Dissertations / Theses on the topic 'Electrolyte hybride'
To see the other types of publications on this topic, follow the link: Electrolyte hybride.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Electrolyte hybride.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Monin, Guillaume. "Stabilisation chimique des électrolytes polymères pour pile à combustible." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00728176.
Abstract:
La dégradation accélérée des membranes conductrices protoniques en pile est en partie due à une oxydation induite par la production d'H2O2. Cette étude présente une stratégie originale de stabilisation chimique d'une matrice de sPEEK par l'inclusion de nano-charges stabilisantes. Quatre nano-charges ont été préparées par fonctionnalisation de nanoparticules de silice avec des fonctions chimiques organosoufrées (disulfure, tétrasulfure et thiourée). Un protocole spécifique de mise en forme des membranes hybrides a permis d'obtenir des composites présentant des propriétés mécaniques et une conductivité protonique compatibles avec l'application pile. Les fonctions polysulfures permettent de ralentir la dégradation de la matrice de sPEEK durant l'étape de mise en œuvre et d'augmenter sa conductivité au cours d'un vieillissement ex-situ (H2O2). En présence de fonctions tétrasulfures, la membrane sPEEK ne se dégrade pas durant un test de 1200h en OCV à 70°C et 100%HR.
2
Chometon, Ronan. "Exploring the role of polymers in scaling up the manufacturing of solid-state batteries." Electronic Thesis or Diss., Sorbonne université, 2024. http://www.theses.fr/2024SORUS046.
Abstract:
Dans un contexte de transition vers les énergies renouvelables et d'électrification de la mobilité, les batteries sont un rouage indispensable à cette transformation. Alors que la technologie lithium-ion est aujourd'hui largement établie, la course à la performance en matière de densité d'énergie mise sur les batteries tout-solide, encore à l'état de prototype. Elles sont basées sur le principe du transfert de charge au travers de contacts purement solides, complexes à former et à maintenir, et donc sources de nombreux problèmes associés à leur fonctionnement. La mise à l'échelle des procédés de fabrication des batteries tout-solide est particulièrement critique et nécessite un changement de stratégie d'assemblage, en abandonnant le format en pastille pour tendre vers un montage en feuillets. Dans ce contexte, nos travaux de recherche ont porté sur le rôle des polymères dans l'adaptation du procédé d'assemblage, en tant que liant des particules inorganiques. Nous avons exploré deux stratégies qui se distinguent par rapport à la nature de ce liant, pouvant être conducteur ou non des ions lithium. Dans une première approche, l'électrolyte polymère PEO:LiTFSI a été utilisé pour préparer des films autosupportés d'électrolyte hybride à haut taux de charges inorganiques Li6PS5Cl, suivant un procédé à sec. L'instabilité des deux électrolytes en contact génère cependant une interphase trop résistive pour assurer une conduction ionique conjointe au sein de l'hybride. Dans un souci de simplification du système, une nouvelle approche a été adoptée, se basant sur un liant non conducteur, le PVDF-HFP, pour la préparation et le coulage en bande d'une encre afin d'obtenir des films d'électrodes et de séparateurs. Une optimisation minutieuse des paramètres a permis d'obtenir des résultats encourageants puisque que proches du système de référence ne contenant pas de liant, et ce même à basse pression de cyclage. La fiabilité du procédé développé au cours de cette thèse ouvre maintenant la voie vers l'assemblage de cellules tout-solide complètes, intégrant une anode à haute densité d'énergie telle que le lithium métalThe imperative transition toward renewable energy sources and the ongoing electrification of transportation position battery technologies at the forefront of this transformation. While the lithium-ion technology is already well-established, the quest for higher energy density has drawn significant attention to the emerging solid-state batteries (SSBs). Their working principle is based on ion and electron transfers through solid-solid contacts, which are complex to master and sustain, giving rise to most of the challenges associated with their realisation. Especially, the capability to scale up SSBs' fabrication process is critical for future implementation and calls for a shift from pellet-type to sheet-type assembly. Thus, this doctoral research delved into the role of polymers in facilitating this transition by exploring two strategies differing on the binder's ability to conduct lithium ions. In the first approach, we capitalised on the polymer electrolyte PEO:LiTFSI favourable mechanical properties to prepare self-standing films of hybrid solid electrolyte with a high content of Li6PS5Cl, using a dry process. However, the instability between the organic and inorganic phases resulted in a resistive interphase that prevents a shared conduction mechanism within the hybrid. After that, we pursued a simpler approach to fabricate self-standing SSBs by employing a conventional non-conductive binder, PVDF-HFP, and using a slurry-based tape casting process. The thorough optimisation of the formulation and preparation of the electrodes and solid-state separators gave promising results, closely approaching the electrochemical performance of binder-free reference SSBs, even under low operating pressure. The reliability of our fabrication process thus paves the way for assembling self-standing solid-state full cells, integrating high energy density anodes such as lithium metal
3
Issa, Sébastien. "Synthèse et caractérisation d'électrolytes solides hybrides pour les batteries au lithium métal." Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0046.
Abstract:
Les problématiques engendrées par l’extraction et l’utilisation intensives des ressources fossiles ont forcé l’humanité à se tourner vers le développement d’énergies renouvelables et de véhicules électriques. Cependant, ces technologies doivent être couplées à des moyens de stockage de l’énergie efficaces pour exploiter leur potentiel. Les systèmes embarquant une anode de lithium métallique sont particulièrement intéressants car ils présentent une densité d’énergie élevée. Cependant, cette technologie souffre de la formation de dendrites pouvant déclencher des courts-circuits provoquant l’explosion du dispositif. Ainsi, de nombreux efforts ont été consacrés à l’élaboration d’électrolytes solides polymères (SPE) à base de POE permettant de constituer une barrière qui bloque la croissance dendritique tout en préservant les propriétés de conduction ionique. Cependant, la conductivité ionique des SPE à base de POE décroît fortement avec la température. A l’heure actuelle, les meilleurs SPE de la littérature nécessiteraient de fonctionner à 60 °C, ce qui signifie qu’une partie de l’énergie de la batterie sera détournée de son utilisation pour maintenir cette température. Ainsi, l’objectif principal de ce travail de thèse est de concevoir un SPE permettant le fonctionnement de la technologie de batterie au lithium métal à température ambiante. Ces SPE doivent présenter une conductivité ionique élevée à température ambiante (≈ 10-4 S.cm-1) et des propriétés mécaniques permettant l’inhibition du phénomène de croissance dendritique. Pour cela, les objectifs du projet sont focalisés sur le développement de nouveaux SPE nanocomposites et hybridesThe problems caused by the intensive extraction and use of fossil fuels have forced humanity to turn to the development of renewable energies and electric vehicles. However, these technologies need to be coupled with efficient energy storage means to exploit their potential. Lithium metal anode systems are particularly interesting because they have a high energy density. However, this technology suffers from the formation of dendrites that can trigger short circuits causing the device to explode. Thus, many efforts have been devoted to the development of POE-based solid polymer electrolytes (SPEs) that provide a barrier that blocks dendritic growth while preserving ionic conduction properties. However, the ionic conductivity of POE-based SPEs decreases strongly with temperature. Currently, the best SPEs in the literature would require operation at 60 °C, which means that some of the energy in the battery will be diverted from its use to maintain this temperature. Thus, the main objective of this thesis work is to design an SPE that allows the operation of lithium metal battery technology at room temperature. These SPEs must exhibit high ionic conductivity at room temperature (≈ 10-4 S.cm-1) and mechanical properties that allow the inhibition of the dendritic growth phenomenon. For this, the objectives of the project are focused on the development of new nanocomposite and hybrid SPEs
4
Leclercq, Florent. "Étude d'électrolytes hybrides solides destinés aux batteries lithium." Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLET068.
Abstract:
Au cours de cette thèse, nous avons comparé deux voies d’élaboration d’un électrolyte solide hybride composé d’un mélange de deux polymères (PEO et PVDF-HFP), d’un sel de lithium (LiTFSI), et d’un réseau de silice formé in situ par voie sol-gel et fonctionnalisé par des groupements imidazolium Dans un premier temps, nous avons utilisé le procédé de coulée-évaporation pour étudier l’influence des différents constituants sur les propriétés physico-chimiques et électrochimiques. Des conductivités de 10⁻⁴ S/cm à 80°C ont été atteintes, ce qui permet de faire cycler des batteries LiFePO₄/Li à des régimes de C/10 à la même température. Le procédé d’extrusion électro-assistée a ensuite été utilisé afin de fabriquer un squelette de nanofibres hybrides PVDF-HFP/silice (fonctionnalisée ou non) dont la porosité est remplie par un mélange PEO/LiTFSI. L’architecture particulière de l’électrolyte ainsi fabriqué permet de découpler les propriétés de conduction des propriétés mécaniques. Les conductivités obtenues à 80°C sont de 5.10⁻⁴ S/cm, ce qui permet de faire cycler des batteries LiFePO₄/Li à des régimes de C/2 à la même température. Les mêmes squelettes hybrides « électrospinnés » ont été évalués en tant que séparateur pour des électrolytes aqueux super-concentrés (également appelés water-in-salt). Leurs excellentes propriétés de mouillage et de rétention permettent d’assurer le fonctionnement d’une batterie LiMn₂O₄/TiO₂ à des régimes atteignant 10C tout en diminuant la quantité d’électrolyte nécessaireThis work focuses on the comparison of two processes for the elaboration of a solid hybrid electrolyte made of a mix of two polymers (PEO and PVDF-HFP), a lithium salt (LiTFSI), and of a silica network made in situ via a sol-gel method and functionalized with imidazolium groups. At first, the influence of the different components on the physicochemical and electrochemical properties of electrolytes made by dry casting is studied. Conductivities of 10⁻⁴ S/cm at 80 °C allow us to cycle LiFePO₄/Li batteries at a C/10 rate at the same temperature. A skeleton of hybrid PVDF-HFP/silica (functionalized or not) nanofibers is synthesized by electrospinning and its porosity is filled with a PEO/LiTFSI mix. The particular architecture of this type of electrolyte enables the decoupling of conduction and mechanical properties. Conductivities of 5.10-4 S/cm at 80 °C allow the cycling of LiFePO₄/Li batteries at a C/2 rate at the same temperature. The same electrospun hybrid membranes are evaluated as separators for hybrid water-in-salt electrolytes. Thanks to their excellent wetting and retention properties, LiMn₂O₄/TiO₂ batteries are cycled at a 10C rate with a low quantity of electrolyte
5
Chamaani, Amir. "Hybrid Polymer Electrolyte for Lithium-Oxygen Battery Application." FIU Digital Commons, 2017. https://digitalcommons.fiu.edu/etd/3562.
Abstract:
The transition from fossil fuels to renewable resources has created more demand for energy storage devices. Lithium-oxygen (Li-O2) batteries have attracted much attention due to their high theoretical energy densities. They, however, are still in their infancy and several fundamental challenges remain to be addressed. Advanced analytical techniques have revealed that all components of a Li-O2 battery undergo undesirable degradation during discharge/charge cycling, contributing to reduced cyclability. Despite many attempts to minimize the anode and cathode degradation, the electrolyte remains as the leading cause for rapid capacity fading and poor cyclability in Li-O2 batteries. In this dissertation, composite gel polymer electrolytes (cGPEs) consisting of a UV-curable polymer, tetragylme based electrolyte, and glass microfibers with a diameter of ~1 µm and an aspect ratio of >100 have been developed for their use in Li-O2 battery application. The Li-O2 batteries containing cGPEs showed superior charge/discharge cycling for 500 mAh.g-1 cycle capacity with as high as 400% increase in cycles for cGPE over gel polymer electrolytes (GPEs). Results using in-situ electrochemical impedance spectroscopy (EIS), Raman spectroscopy, and scanning electron microscopy revealed that the source of the improvement was the reduction of the rate of lithium carbonates formation on the surface of the cathode. This decrease in formation rate afforded by cGPE-containing batteries was possible due to the decrease of the rate of electrolyte decomposition. The increase in solvated to the paired Li+ ratio at the cathode, afforded by increased lithium transference number, helped lessen the probability of superoxide radicals reacting with the tetraglyme solvent. This stabilization during cycling helped prolong the cycling life of the batteries. The effect of ion complexes on the stability of liquid glyme based electrolytes with various lithium salt concentrations has also been investigated for Li-O2 batteries. Charge/discharge cycling with a cycle capacity of 500 mAh·g-1 showed an improvement as high as 300% for electrolytes containing higher lithium salt concentrations. Analysis of the Raman spectroscopy data of the electrolytes suggested that the increase in lithium salt concentration afforded the formation of cation-solvent complexes, which in turn, mitigated the tetragylme degradation.
6
Lundgren, Henrik. "Thermal Aspects and Electrolyte Mass Transport in Lithium-ion Batteries." Doctoral thesis, KTH, Tillämpad elektrokemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-166857.
Abstract:
Temperature is one of the most important parameters for the performance, safety, and aging of lithium-ion batteries and has been linked to all main barriers for widespread commercial success of electric vehicles. The aim of this thesis is to highlight the importance of temperature effects, as well as to provide engineering tools to study these. The mass transport phenomena of the electrolyte with LiPF6 in EC:DEC was fully characterized in between 10 and 40 °C and 0.5 and 1.5 M, and all mass transport properties were found to vary strongly with temperature. A superconcentrated electrolyte with LiTFSI in ACN was also fully characterized at 25 °C, and was found to have very different properties and interactions compared to LiPF6 in EC:DEC. The benefit of using the benchmarking method termed electrolyte masstransport resistivity (EMTR) compared to using only ionic conductivity was illustrated for several systems, including organic liquids, ionic liquids, solid polymers, gelled polymers, and electrolytes containing flame-retardant additives. TPP, a flame-retardant electrolyte additive, was evaluated using a HEV load cycle and was found to be unsuitable for high-power applications such as HEVs. A large-format commercial battery cell with a thermal management system was characterized using both experiments and a coupled electrochemical and thermal model during a PHEV load cycle. Different thermal management strategies were evaluated using the model, but were found to have only minor effects since the limitations lie in the heat transfer of the jellyroll.Temperatur är en av de viktigaste parametrarna gällande ett litiumjonbatteris prestanda, säkerhet och åldring och har länkats till de främsta barriärerna för en storskalig kommersiell framgång för elbilar. Syftet med den här avhandlingen är att belysa vikten av temperatureffekter, samt att bidra med ingenjörsverktyg att studera dessa. Masstransporten för elektrolyten LiPF6 i EC:DEC karakteriserades fullständigt i temperaturintervallet 10 till 40 °C för LiPF6-koncentrationer på 0.5 till 1.5 M. Alla masstransport-egenskaper fanns variera kraftigt med temperaturen. Den superkoncentrerade elektrolyten med LiTFSI i ACN karakteriserades även den fullständigt vid 25 °C. Dess egenskaper och interaktioner fanns vara väldigt annorlunda jämfört med LiPF6 i EC:DEC. Fördelen med att använda utvärderingsmetoden elektrolytmasstransportresistivitet (EMTR) jämfört med att endast mäta konduktivitet illustrerades för flertalet system, däribland organiska vätskor, jonvätskor, fasta polymerer, gellade polymerer, och elektrolyter med flamskyddsadditiv. Flamskyddsadditivet TPP utvärderades med en hybridbils-lastcykel och fanns vara olämplig för högeffektsapplikationer, som hybridbilar. Ett kommersiellt storformatsbatteri med ett temperatur-kontrollsystem karakteriserades med b.de experiment och en kopplad termisk och elektrokemisk modell under en lastcykel utvecklad för plug-inhybridbilar. Olika strategier för kontroll av temperaturen utvärderades, men fanns bara ha liten inverkan på batteriets temperatur då begränsningarna för värmetransport ligger i elektrodrullen, och inte i batteriets metalliska ytterhölje.
QC 20150522
Swedish Hybrid Vehicle Center
7
Romer, Frederik. "Multinuclear NMR of hybrid proton electrolyte membranes in metal oxide frameworks." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/89874/.
8
Seck, Serigne. "Elaboration de matériaux hybrides organiques / inorganiques par extrusion réactive : Application en pile à combustible." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0027.
Abstract:
A l’heure actuelle, les piles à combustible à membrane échangeuse de protons (PEMFC) les plus avancées, qu’elles soient disponibles commercialement ou intégrées dans des démonstrateurs, sont réalisées avec des électrolytes polymères perfluorosulfonés de types Nafion®. En effet, ce type de polymère est celui qui présente à la fois les meilleures performances et la plus grande durée de vie sans pour autant qu’elles soient suffisantes, et ce, quelles que soient les applications (portable, stationnaire, transport). En effet ce polymère présente toutefois trois inconvénients majeurs : son prix, sa perméation au méthanol et sa perte de performance (et surtout de conductivité) dès 80-85 °C. Selon les projections avec les technologies actuelles (source DOE), le prix de vente du Nafion® serait de 80 $/m2 pour une production de 1 Mm2. Il existe un réel besoin de développer de nouveaux matériaux pour membranes échangeuses de protons présentant d’excellentes performances (propriétés mécaniques, imperméabilité maximale au méthanol et H2, conduction protonique..) sur une large gamme de températures, typiquement entre 25 et 150°C (selon l’application visée), mais présentant également un coût de fabrication réduit. Or aujourd’hui, ces différentes fonctions sont assurées par un seul polymère perfluorosulfoné ce qui est le problème principal. Ainsi, l’intérêt du projet est de combiner les avantages d’un matériau hybride obtenu par génération in situ de la phase inorganique (Sol-Gel) nanométrique avec l’utilisation d’un procédé en continu de mise en œuvre par extrusion (voie fondu), exempt de tout solvant et facilement transférable industriellement. La conduction protonique sera assurée par des fonctions sulfoniques générées grâce à l'oxydation des sites fonctionnels apportés par le précurseur fonctionnelFuel cells technologies are electrochemical energy conversion devices and have a real potential to revolutionize the way to produce energy, offering cleaner, more-efficient alternatives to combustion of gasoline and other fossil fuels. In that way, the Proton Exchange Membrane Fuel Cells (PEMFC) are probably the most studied. Those fuel cells are mainly based on perfluorosulfonic acid membranes, such as Nafion®. However, Nafion® membranes, present some limitations such as dehydration at high temperatures or at low relative humidity rate leading to a decrease of proton conductivity and thus poor PEMFC performance. Consequently, PEMFC require significant improvements prior to be largely used in the automobile field. Research efforts have been oriented on the development of new materials for the PEMFC membrane as it is the main limitative component for high temperature fuel cell. In the present contribution, we wish to report the validation of a new concept of hybrid materials for the realization of proton exchange membranes. The originality of this hybrid concept is based on the contribution of both phases’ specific properties. We investigated the preparation of hybrid materials based on an inert polymer matrix (low cost) providing the mechanical stability embedding inorganic phase providing the necessary properties of proton-conduction and water retention. Hybrid nanocomposite membranes were synthesized using evaporation and recasting technique from solution containing dispersion of inorganic particles in the adequate polymer. Scanning electron microscopy (SEM) images for membrane morphology and proton conductivity results using impedance measurements from hybrid membranes will be presented. The performance of the membrane-electrode assembly (MEA) using the hybrid membrane was also evaluated by a fuel cell test. Finally, we wish to present a promising way of research based on Sol-Gel approach to generate a proton-conducting inorganic phase into the polymer matrix
9
Boaretto, Nicola. "Inorganic-organic hybrid polymer electrolytes for secondary lithium metal batteries." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424435.
Abstract:
Polymer electrolytes are an important class of ionic conducting materials, which find application essentially in electrochemical storage devices, such as secondary lithium batteries or fuel cells. Regarding the application in lithium batteries, the interest on polymer electrolytes arises primarily from their inherent safety, at least in comparison with classical liquid electrolytes. Furthermore, polymer electrolytes show higher compatibility with lithium metal. The use of lithium metal as anode material allows a reduction of the total cell mass and thus an increase of its specific energy.
This study describes the synthesis and the physical properties of polysiloxane/polyether-based hybrid polymer electrolytes. The structural, thermo-mechanical, electrochemical and transport properties of the hybrid electrolytes are characterized by means of several analytical techniques. Finally, the performances of lithium-metal polymer batteries with the best performing materials are analyzed. An attempt to enhance the cycling life of these cells by passivation of the lithium electrodes is also described.
The materials are synthesized by sol-gel reaction of functionalized alkoxysilanes and by polymerization of vinyl or epoxide functionalities. The synthesized hybrid polymer electrolytes show good ionic conductivities (up to 8∙10-5 S•cm-1 at room temperature), and high thermo-mechanical and electrochemical stabilities. Broadband electric spectroscopy analysis (BES) shows that the ionic mobility is maximized if a) short-range ion-ion interactions are negligible and b) ordered stacking of the polyether chains is hindered. If both conditions are satisfied, the charge motion is modulated by the segmental motion of the polyether chains.
Full cell tests at 60 °C show that these materials can be used as electrolytes in lithium metal batteries, even though a moderate capacity fade upon cycling is observed. This is attributed, among other factors, to contact and electrochemical stability issues between lithium and electrolyte. Pre-coating of the Lithium surface with cyclic carbonates, or the introduction of a softer electrolyte as buffer, helps preventing electrolyte degradation and improving the performance and cycling life of Li-metal polymer cells.Gli elettroliti polimerici costituiscono un’importante classe di materiali a conduzione ionica, che trova applicazione essenzialmente in dispositivi di stoccaggio elettrochimici, quali batterie al litio o celle a combustibile. Nel campo delle batterie al litio, l’interesse per questi materiali deriva principalmente dalla loro non infiammabilità, che li distingue dagli elettroliti liquidi attualmente utilizzati. In aggiunta, gli elettroliti polimerici mostrano una maggiore compatibilità nei confronti del litio metallico. L’utilizzo di questo come materiale anodico permette una riduzione della massa della cella e quindi un aumento dell’energia specifica della stessa. Questo studio descrive la sintesi e la caratterizzazione di elettroliti polimerici ibridi a base polisilossanica/polieterea. La sintesi include una reazione d’idrolisi/co-condensazione tra alcossisilani funzionalizzati e la reticolazione di gruppi terminali vinilici o epossidici. La struttura, le proprietà termomeccaniche, elettrochimiche e di trasporto sono caratterizzate tramite varie tecniche analitiche. Infine, i materiali più promettenti sono testati in celle con anodi in litio metallico. Lo studio descrive, infine, un tentativo di migliorare la ciclabilità delle celle litio/polimero tramite pre-passivazione degli elettrodi in litio. I materiali sintetizzati sono caratterizzati da buona conducibilità ionica (fino a 8∙10-5 S•cm-1 a temperatura ambiente) e da buona stabilità termomeccanica ed elettrochimica. L’analisi degli spettri elettrici (BES) rivela che la mobilità ionica è massimizzata a) in assenza di interazioni inter-ioniche a corto raggio e b) in assenza di ordine nei domini polieterei. Se queste due condizioni sono soddisfatte, la migrazione ionica a lungo raggio è modulata dal moto segmentale delle catene polieteree. Test in cella a 60 °C dimostrano che questi materiali possono essere utilizzati come elettroliti polimerici in celle con anodo in litio metallico, seppur con una moderata perdita di capacità. Questa è in parte attribuita a problemi di contatto e di stabilità elettrochimica tra l’elettrolita e l’anodo. La pre-passivazione degli elettrodi in litio metallico protegge l’elettrolita dal deterioramento e permette di migliorare le prestazioni in cella.
10
Meyer, Mathieu. "Membranes électrolytes à porteurs de charge Li+." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20119/document.
Abstract:
La demande actuelle en batteries lithium-ion « tout solide » adaptées aux applications mobiles asuscité d'importantes recherches sur des membranes électrolytes polymères de plus en plussophistiquées. Cette thèse porte sur la synthèse et la caractérisation mécanique, thermique etstructurale de nouveaux matériaux électrolytes polymères nanocomposites résultant de la réticulationpar procédé sol-gel de chaînes de poly(oxyde d'éthylène) (PEO) fonctionnalisées aux deux extrémitéspar des groupements alkoxysilane. Les nano-domaines polysilsesquioxanes ainsi formés par hydrolysecondensation,génèrent un haut degré de réticulation et jouent le rôle de nanocharges, apportant unerésistance mécanique permettant d'incorporer des quantités élevées de plastifiant. En outre, leprocédé sol-gel permet de fonctionnaliser ces nano-domaines avec des groupements de type sulfonateou perfluorosulfonate de lithium, qui fournissent des porteurs de charge Li+ de façon uniforme au seinde la membrane. De plus, l'immobilisation des anions par liaisons covalentes supprime leurcontribution à la conductivité, ce qui assure au sein de l'électrolyte (alors dit single-ion) une conductionunipolaire cationique, indispensable pour éviter ultérieurement la formation de dendrites de lithium aucours des cycles de charge et décharge. L'étude de la conductivité ionique de ces membranes, à l'étatsec ou après gonflement dans le carbonate de propylène, a conduit à une réflexion sur la dynamique ducation lithium au sein des membranes nanocomposites et sur les différentes voies envisageables pouraméliorer les performances de ces électrolytesThe topical demand in all-solid lithium-ion batteries suitable for portable consumer electronicdevices has triggered extensive research on more and more sophisticated polymer electrolytemembranes (PEM).This PhD work deals with the synthesis and the mechanical, thermal andstructural characterization of new nanocomposite PEM arising from the sol-gel cross-linking ofPEO chains end-capped with alkoxysilane groups. Thus, the polysilsesquioxane nano-domainsformed by hydrolysis-condensation reactions form a high density of cross-links and play the roleof nanocharges, giving rise to mechanical resistance, which allows incorporating high amounts ofplasticizer. Moreover, sol-gel process allows the functionalization of these nanodomains withlithium sulfonate or perfluorosulfonate groups, which supply Li+ charge carriers homogeneouslydispersed throughout the membrane. In addition the immobilization of the anions via covalentbonds prevents them from contributing to the overall conductivity, thus ensuring a single-ionconduction, which is a compulsory condition to prevent the further formation of lithium dendriteson charge-discharge cycles. The ionic conductivity study of the membranes, in the dry state orafter swelling in propylene carbonate, was done. It led to discuss the dynamics of lithium cation inthe nanocomposite membranes and the possible ways to improve their conductionperformances
11
Chaker, Juliano. "Corrélations structure/propriétés de conduction ionique dans des matériaux hybrides siloxane-poly(oxydepropylène) dopés par des sels de sodium et de potassium." Paris 11, 2004. http://www.theses.fr/2004PA112190.
Abstract:
Les matériaux hybrides siloxane-poly(oxyéthylène) (PEO) ou siloxane-poly(oxypropylène) (PPO) obtenus par le procédé sol-gel présentent un grand intérêt scientifique et technologique du fait de l'interpénétration des réseaux inorganique et organique à l'échelle nanométrique. Lorsque ces matériaux hybrides sont dopés avec des sels alcalins, ils présentent une conductivité ionique élevée, similaire aux polymères conducteurs ioniques (10-4 S/cm), tout en présentant des propriétés mécaniques et optiques bien meilleures. Une des limitations de tous ces matériaux est le manque de connaissance sur la nature des espèces mobiles (ions libres ou solvatés, paires ou agrégats d'ions) responsables de la conduction. Afin d'améliorer encore les propriétés ioniques, la connaissance de la nature et de la structure locale autour des ions mobiles est donc fondamentale. En d'autres mots, l'objectif de ce travail est d'établir des corrélations entre la structure locale des porteurs de charge (coordinence, sphère de solvatation) et les aspects électriques macroscopiques (conduction ionique). Notre approche consiste donc à analyser l'ordre local autour des sels dissous par les spectroscopies d'absorption de rayons X (XANES, EXAFS), de Raman et de RMN afin de corréler ces mesures aux paramètres de conduction ionique. L'établissement de telles relations structure/propriétés aux différentes échelles spatiales est évidemment un des points clé pour optimiser de tels matériauxSiloxane-poly(oxi propylene) (PPO) or Siloxane-poly(oxi propylene) hybrid materials prepared by the sol-gel route show increasing scientific and technological interest due to its particular structure in which the polymer chains are grafted to the inorganic nanoparticules. When doped within alkaline salts these hybrids present ionic conductivity similar to that of ionic conductive polymers (10-4 S/cm), and both their mechanical and optical properties are improved. However, the nature of the mobile species, are responsible for there conductivity (free ions, ion-pairs, aggregates) is not well established. So that the knowledge of the nature and the local structure around the mobile ions is the challenger to improve the ionic properties. The but of this work was to establish the correlations between the local structure around the charge carriers (coordination shell, solvation sphere) and the macroscopic conductivity. To reach this objective the local structure was probed by X ray absorption (XANES and EXAFS), Raman and NMR spectroscopy and the results related to that obtained from conductivity measurements
12
Meera, P. "Nafion based hybrid polymer electrolytes and nanocomposites: design and electrochemical investigations." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2009. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2726.
13
DE, BONIS CATIA. "Hybrid polymer electrolytes for proton exchange membrane fuel cells: synthesis and applications." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/1129.
Abstract:
Le celle a combustibile con membrane a scambio protonico (PEMFCs) sono alternative sorgenti di energia che offrono numerosi vantaggi come l’alta efficienza, l’alta densità di potenza e la bassa emissione d’inquinanti. Esse sono impiegate nelle macchine ad idrogeno e nei dispositivi elettronici quali computer e cellulari alimentati con metanolo. La diffusione su larga scala di queste tecnologie punta sullo sviluppo di membrane a scambio protonico di nuova generazione, il cui costo di produzione sia compatibile con un mercato di massa. Tali conduttori protonici devono esibire una buona conducibilità, stabilità chimica e termica.
Nel presente lavoro, diverse strategie sono state impiegate per la preparazione di materiali a conduzione protonica a partire dai polimeri termoplastici aromatici: polietereterchetone (PEEK) e polifenilsolfone (PPSU). Di particolare rilevanza è la funzionalizzazione di tali polimeri mediante l’introduzione sulla catena aromatica di gruppi solfonici e gruppi contenenti silicio. Infatti, questo approccio sintetico permette di controllare la microstruttura del polimero, modulando il rapporto tra la fase idrofila e quella idrofoba, da cui dipendono fortemente le prestazioni dell’elettrolita.
Diversi tipi di membrane sono state preparate impiegando: PEEK solfonato (SPEEK) e/o PPSU solfonato, variamente funzionalizzati con gruppi contenenti silicio, al fine di ottenere l’effetto sinergico derivante dalla combinazione di polimeri aventi diverse conducibilità protonica e caratteristiche meccaniche.
I sistemi ibridi sono stati preparati mediante la reazione sol-gel che ha portato alla formazione dei legami covalenti Si-O-Si tra due derivati del PPSU diversamente funzionalizzati. Le membrane blend sono state invece preparate mescolando, durante il processo di casting, derivati del PEEK e/o PPSU. La caratterizzazione dei materiali ha riguardato l’analisi della struttura dei polimeri sintetizzati e delle proprietà chimico-fisiche ed elettrochimiche delle membrane. Risultati molto positivi sono stati ottenuti dai test eseguiti sulle membrane in un prototipo di cella a combustibile operante a metanolo diretto.Proton exchange membrane fuel cells (PEMFCs) are promising power sources emerging among alternative energy conversion systems, because they can operate at relatively low temperature and offer numerous benefits, such as high efficiency, high power density and low polluting emissions. The present dissertation deals with the development of new proton conducting membranes having good conductivity, chemical and thermal stability, low methanol permeability and low cost. The main strategy used in this work was the preparation of sulfonated and silylated polyetheretherketone (PEEK) and polyphenylsulfone (PPSU) as membrane materials, because this synthetic approach represents a powerful tool to modulate the proton conductivity and hydrolytic stability of the electrolyte by the dosage of sulfonic acid groups and inorganic moieties covalently bound to the aromatic chains. Several types of proton exchange membranes were studied. Sulfonated and silylated PEEK and/or PPSU were used to prepare systems where two components resulted crosslinked by physical interactions or covalent bonds, obtaining the synergic effect of polymers having different conductivity and mechanical properties. • Sulfonated and silylated polyetheretherketone PhSi0.1S0.9PEEK (degree of sulfonation DS=0.9, and degree of silylation DSi=0.1) was synthesized via (i) sulfonation of PEEK, (ii) conversion of sulfonated polyetheretherketone (S0.9PEEK) into sulfonyl chlorinated derivative (PEEKSO2Cl), (iii) lithiation of PEEKSO2Cl and subsequent addition of PhSiCl3, followed by hydrolysis. The solubility of PEEKSO2Cl in organic solvent allows the silylation reaction to be carried out in homogeneous conditions. The structural characterization of the products by 1H and 13C NMR and ATR/FTIR spectroscopies highlighted the success of the synthetic pathway. The thermogravimetric analysis of PEEK derivatives indicated that the presence of the inorganic moieties stabilizes the aromatic matrix of the sulfonated polyetheretherketone. Blends of PhSi0.1S0.9PEEK and S0.5PEEK (DS=0.5) were prepared using different weight ratios of the two polymers. The membranes were characterized by water uptake measurements and electrochemical impedance spectroscopy (EIS). The results converge to indicate that the developed materials are promising electrolytes for PEMFC application. • Silylated and sulfonated polyphenylsulfone PhSi0.2S2PPSU (DS=2.0 and DSi=0.2) was synthesized via (i) lithiation of PPSU and subsequent addition of PhSiCl3, followed by hydrolysis, (ii) sulfonation by reaction with concentrated sulphuric acid. The chemical structure of polymers was investigated by 1H and 13C NMR, and ATR/FTIR, verifying the success of the developed synthetic route. Blends of PhSi0.2S2PPSU and S0.5PEEK were prepared, obtaining electrolytes with higher hydrolytic stability and increased proton conductivity with respect to those of pure S0.5PEEK membrane. Blend membranes showed also better performance in DMFC, where a reduced methanol permeability and adequately high power density values were observed, at temperature values as high as 100°C. All these features identify the prepared blend membranes as promising electrolytes for DMFC operating at intermediate temperatures. • Two silylated and sulfonated PPSU derivatives: Si0.2S2PPSU (DS=2.0 and DSi=0.2) and Si0.03S0.05PPSU (DS=0.05 and DSi=0.03) were synthesized following two different routes. In the first one, PPSU was silylated by reaction with SiCl4, then sulfonated by reaction with concentrated sulphuric acid, and Si0.2S2PPSU was obtained. In the second route, the use of the mild sulfonating agent ClSO3Si(CH3)3 allowed a careful control of the degree of sulfonation, and PPSU with a lower DS was obtained. Subsequent silylation by reaction with SiCl4 led to the final product Si0.03S0.05PPSU. An organic-inorganic hybrid polymer HSiSPPSU was synthesized by non-hydrolytic sol–gel reaction of Si0.2S2PPSU and Si0.03S0.05PPSU. The condensation between the silanol groups of the two polymers led to the formation of Si-O-Si bonds, as highlighted by analysis of ATR/FTIR spectra. The electrochemical characterization of HSiSPPSU membranes by EIS showed adequately high conductivity values to make the hybrid polymer a suitable candidate for application in PEMFCs operating at T > 100°C. The strategies followed in this work seems to be an effective way to overcome some drawbacks related to conventional polymer membranes currently used, demonstrating the relevant role played by synthesis in the preparation of electrolytes for PEMFCs.
14
Gu, Bin. "Power Converter and Control Design for High-Efficiency Electrolyte-Free Microinverters." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/25236.
Abstract:
Microinverter has become a new trend for photovoltaic (PV) grid-tie systems due to its advantages which include greater energy harvest, simplified system installation, enhanced safety, and flexible expansion. Since an individual microinverter system is typically attached to the back of a PV module, it is desirable that it has a long lifespan that can match PV modules, which routinely warrant 25 years of operation. In order to increase the life expectancy and improve the long-term reliability, electrolytic capacitors must be avoided in microinverters because they have been identified as an unreliable component. One solution to avoid electrolytic capacitors in microinverters is using a two-stage architecture, where the high voltage direct current (DC) bus can work as a double line ripple buffer.
For two-stage electrolyte-free microinverters, a high boost ratio dc-dc converter is required to increase the low PV module voltage to a high DC bus voltage required to run the inverter at the second stage. New high boost ratio dc-dc converter topologies using the hybrid transformer concept are presented in this dissertation. The proposed converters have improved magnetic and device utilization. Combine these features with the converter's reduced switching losses which results in a low cost, simple structure system with high efficiency. Using the California Energy Commission (CEC) efficiency standards a 250 W prototype was tested achieving an overall system efficiency of 97.3%.
The power inversion stage of electrolyte-free microinverters requires a high efficiency grid-tie inverter. A transformerless inverter topology with low electro-magnetic interference (EMI) and leakage current is presented. It has the ability to use modern superjunction MOSFETs in conjunction with zero-reverse-recovery silicon carbide (SiC) diodes to achieve ultrahigh efficiency. The performance of the topology was experimentally verified with a tested CEC efficiency of 98.6%.
Due to the relatively low energy density of film capacitors compared to electrolytic counterparts, less capacitance is used on the DC bus in order to lower the cost and reduce the volume of electrolyte-free microinverters. The reduced capacitance leads to high double line ripple voltage oscillation on DC bus. If the double line oscillation propagates back into the PV module, the maximum power point tracking (MPPT) performance would be compromised. A control method which prevents the double line oscillation from going to the PV modules, thus improving the MPPT performance was proposed.
Finally, a control technique using a single microcontroller with low sampling frequency was presented to effectively eliminate electrolyte capacitors in two-stage microinverters without any added penalties. The effectiveness of this control technique was validated both by simulation and experimental results.Ph. D.
15
Maouacine, Koceila. "Matériaux hybrides poreux silice/polymère comme électrolytes pour batterie lithium-ion tout solide." Electronic Thesis or Diss., Aix-Marseille, 2023. http://www.theses.fr/2023AIXM0024.
Abstract:
La conception de batteries lithium-ion utilisant un électrolyte solide est actuellement l’une des voies les plus étudiées pour s’affranchir des problèmes de sécurité lié à ces dispositifs. Dans ces travaux de thèse, nous proposons une nouvelle approche d'élaboration d'un électrolyte hybride poreux silice/polymère, contenant une fraction massique plus élevée de silice mésoporeuse que de polymère. Deux morphologies de matériaux hybrides de silice ont été étudiées : sous forme de poudres compressées (pastilles) et sous forme de films minces. Dans la première partie du travail, une poudre de silice hybride a été synthétisée puis calcinée pour libérer la porosité. La silice mésoporeuse a, ensuite, été fonctionnalisée par imprégnation en solution avec différents polymères de type PEG de faible poids moléculaire puis, par un sel de lithium, le LiTFSI. Les poudres hybrides ont été compressées sous forme de pastilles, présentant une porosité inter- et intraparticulaire. Il a été montré que, les pastilles hybrides présentent des propriétés de conductivité ionique prometteuse lorsque les porosités inter et intraparticulaires sont remplies par le complexe PEG-LiTFSI pour PEG de faible masse molaire (300-600 g/mol). Dans la seconde partie, des films de silice mésoporeuse ont été déposés sur une électrode de carbone vitreux en utilisant une électrode à disque rotatif (RDE). Après avoir caractérisé ces films du point des propriétés texturales et de la microstructure, ces derniers ont été fonctionnalisés par le complexe PEG-LiTFSI via un procédé d’imprégnation et l’étude préliminaire de leur conductivité ionique a été réaliséeThe design of lithium-ion batteries using a solid electrolyte is currently one of the most studied ways to overcome safety problem of these devices. In this thesis work, we propose a new approach to develop a porous silica/polymer hybrid electrolyte, containing a higher weight fraction of mesoporous silica than polymer. Two morphologies of silica hybrid materials were studied: as compressed powders (pellets) and as thin films. In the first part of the work, a hybrid silica powder was synthesized and then calcined to liberate the porosity. The mesoporous silica was then functionalized with different polymers of PEG of low molecular weight then by a simple solution impregnation. The hybrid powders were shaped as pellets, presenting inter- and intra-particle porosity. It was shown that the hybrid pellets present promising ionic conductivity properties when the inter- and intraparticle porosities are filled with the PEG-LiTFSI complex for PEG of low molar mass (300-600 g/mol). In the second part, mesoporous silica films were deposited on a glassy carbon electrode using a rotating disc electrode (RDE). After the characterization of these films from a textural properties and a microstructure point of view, they were functionalized by the PEG-LiTFSI complex via an impregnation process and the preliminary study of their ionic conductivity was performed
16
Zamanillo, López Isabel. "Membranes hybrides pour pile à combustible." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI120/document.
Abstract:
La pile à combustible est une solution d'avenir pour produire de l'électricité propre. Cependant des problèmes technologiques limitent pour le moment un déploiement à grande échelle. C’est au cœur de pile et plus particulièrement de la membrane conductrice ionique séparant l’anode et la cathode, que certaines difficultés se posent. Nous pouvons ainsi citer l’impossibilité d’améliorer l’efficacité du catalyseur et le rendement du dispositif en augmentant simplement la température de fonctionnement (100 - 120°C). En effet, la membrane de référence (Nafion) perd ses propriétés thermomécaniques au-delà de 80°C, alors que les membranes alternatives (offrant une meilleure stabilité thermomécanique) sont victimes d’un vieillissement chimique trop rapide qui induit un arrêt inopiné du dispositif. Pour lever ce verrou technologique, nous proposons une nouvelle stratégie qui repose sur le développement de membranes nano-composites constituées d'une matrice ionomère commerciale (non réticulée) dans laquelle nous introduirons des précurseurs aptes à former une phase sol-gel offrant une stabilisation chimique et thermomécanique (réticulée). C'est le contrôle de la chimie de ce réseau, de sa morphologie et de sa localisation dans la membrane hôte qui permettra l'amélioration des propriétés de la membrane hybride ainsi obtenue.Nous avons réalisé une analyse minutieuse de l'effet d’un traitement hydrothermique sur la microstructure des membranes sPEEK. Grâce à cette analyse nous pouvons relier la microstructure avec les propriétés fonctionnelles de l’ionomère pour obtenir des membranes sPEEK mieux nanostructurées et donc plus performantes. Le procédé sol-gel permet la croissance de la phase sol-gel sans perturbation de la nanostructuration initiale de l'ionomère. Cette stratégie permet donc de contrôler la distribution et la morphologie de la phase inorganique.Le processus d'élaboration des membranes hybrides a été étudié. Nous avons étudié l'influence des paramètres de fabrication sur les propriétés des membranes hybrides, et ainsi pu produire des membranes hybrides optimisées. Les propriétés physiques et chimiques de ces membranes ont été évaluées par de nombreuses techniques (SANS, IR, DMA, etc.). L'influence de la structure chimique (degré de réticulation) du réseau sol-gel des membranes hybrides et l'impact de la teneur en sol-gel et de sa distribution (morphologie) dans la membrane hôte sur les propriétés fonctionnelles sont présentés. Nous observons une grande influence du dégrée de réticulation et de la quantité de sol-gel présent dans la membrane qui conditionne les propriétés fonctionnelles de la membraneFuel cell is a promising solution for clean production of hydrogen based energy. However to achieve a large-scale deployment of this technology, issues remain to be addressed. One of the remaining problems concerns the heart of the cell (polymer membrane sandwiched between two electrodes). We can stress the fact that it is impossible to improve the catalyst efficiency and the cell performance by a simple increase of the operating temperature (100-120 °C). Indeed the reference membrane (Nafion) exhibit a step decrease of its thermomechanical properties beyond 80 °C, whereas alternative membranes (with a better thermomechanical stability) are victims of a much faster chemical aging resulting into unexpected failure of the device.Our main objective is to develop novel hybrid membranes consisting of a commercial ionomer matrix in which we will introduce precursors capable to form a sol-gel phase. It will result on membrane composed of two interpenetrating phases, an ion conductive non-crosslinked polymer phase and a crosslinked inorganic phase providing chemical and thermomechanical stabilization. The control of the chemistry of this sol-gel phase, its morphology and its location in the membrane, which will improve the membrane properties, are essential to consider the development of these membranes for fuel cells.A careful analysis of the hydrothermal treatment effect on the microstructure of sPEEK membranes has been performed. Thanks to this analyse we can relate the microstructure with the functional properties of the polymer. The sol-gel process enables the growth of the sol-gel phase without disturbance of the initial nanostructured membrane. This strategy makes possible to control the distribution and morphology of the inorganic phase.The elaboration process of hybrid membrane has been studied. We presented the influence of elaboration parameters regarding the best conditions to prepare an optimized hybrid membrane. The physical and chemical properties of the inorganic phase were evaluated by many techniques (SANS, IR, DMA, etc.). The influence of the chemical structure (cross-linking degree) of the sol-gel network andthe impact of the sol-gel content and its distribution (morphology) into the host membrane on their functional properties is presented. We observed the great influence of cross-linking degree and of the amount of sol-gel present in the membrane which determines the functional properties of the membrane
17
Goh, Wei Chiun. "Hybrid hydrogen energy stored in stand-alone power system." Thesis, Curtin University, 2008. http://hdl.handle.net/20.500.11937/578.
Abstract:
A stand-alone power system is an autonomous system that supplies electricity to the user load without being connected to the electric grid. This kind of decentralized system is frequently located in remote and inaccessible areas. The purpose of this thesis is the modelling and simulation of a solar hydrogen hybrid power system to supply the typical residential electric customers in stand alone. It couples a photovoltaic (PV) generator, an alkaline water electrolyzer, a storage gas tank, a proton exchange membrane fuel cell (PEMFC), and power conditioning units (PCU) to give different system topologies. The overall mathematical model was obtained by integrating between their various subsystems models derived from literature. The system is intended to be an environmentally friendly solution since it tries maximizing the use of a renewable energy source. The results of the simulations showed that the hydrogen is one of the future energy storage mediums by using both TRNSYS software and HOMER software.
18
Yahata, Yoshikazu. "Extended Design of Concentrated-Polymer-Brush-Decorated Hybrid Nanoparticles and Their Use for Phase-Separation Control." Kyoto University, 2018. http://hdl.handle.net/2433/232486.
19
Kroll, Douglas M. "Using polymer electrolyte membrane fuel cells in a hybrid surface ship propulsion plant to increase fuel efficiency." Thesis, Cambridge Massachusetts Institute of Technology, 2010. http://hdl.handle.net/10945/4941.
Abstract:
CIVINSApproved for public release; distribution is unlimited
An increasingly mobile US Navy surface fleet and oil price uncertainty contrast with the Navy's desire to lower the amount of money spent purchasing fuel. Operational restrictions limiting fuel use are temporary and cannot be dependably relied upon. Long term technical research toward improving fuel efficiency is ongoing and includes advanced gas turbines and integrated electric propulsion plants, but these will not be implemented fleet wide in the near future. The focus of this research is to determine if a hybrid fuel cell and gas turbine propulsion plant outweigh the potential ship design disadvantages of physically implementing the system. Based on the potential fuel savings available, the impact on surface ship architecture will be determined by modeling the hybrid fuel cell powered ship and conducting a side by side comparison to one traditionally powered. Another concern that this solution addresses is the trend in the commercial shipping industry of designing more cleanly running propulsion plants.
20
Kroll, Douglas M. (Douglas Michael). "Using polymer electrolyte membrane fuel cells in a hybrid surface ship propulsion plant to increase fuel efficiency." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61909.
Abstract:
Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 59).
An increasingly mobile US Navy surface fleet and oil price uncertainty contrast with the Navy's desire to lower the amount of money spent purchasing fuel. Operational restrictions limiting fuel use are temporary and cannot be dependably relied upon. Long term technical research toward improving fuel efficiency is ongoing and includes advanced gas turbines and integrated electric propulsion plants, but these will not be implemented fleet wide in the near future. The focus of this research is to determine if a hybrid fuel cell and gas turbine propulsion plant outweigh the potential ship design disadvantages of physically implementing the system. Based on the potential fuel savings available, the impact on surface ship architecture will be determined by modeling the hybrid fuel cell powered ship and conducting a side by side comparison to one traditionally powered. Another concern that this solution addresses is the trend in the commercial shipping industry of designing more cleanly running propulsion plants.
Douglas M. Kroll.
S.M.in Engineering and Management
Nav.E.
21
Gazey, Ross Neville. "Sizing hybrid green hydrogen energy generation and storage systems (HGHES) to enable an increase in renewable penetration for stabilising the grid." Thesis, Robert Gordon University, 2014. http://hdl.handle.net/10059/947.
Abstract:
A problem that has become apparently growing in the deployment of renewable energy systems is the power grids inability to accept the forecasted growth in renewable energy generation integration. To support forecasted growth in renewable generation integration, it is now recognised that Energy Storage Technologies (EST) must be utilised. Recent advances in Hydrogen Energy Storage Technologies (HEST) have unlocked their potential for use with constrained renewable generation. HEST combines Hydrogen production, storage and end use technologies with renewable generation in either a directly connected configuration, or indirectly via existing power networks. A levelised cost (LC) model has been developed within this thesis to identify the financial competitiveness of the different HEST application scenarios when used with grid constrained renewable energy. Five HEST scenarios have been investigated to demonstrate the most financially competitive configuration and the benefit that the by-product oxygen from renewable electrolysis can have on financial competitiveness. Furthermore, to address the lack in commercial software tools available to size an energy system incorporating HEST with limited data, a deterministic modelling approach has been developed to enable the initial automatic sizing of a hybrid renewable hydrogen energy system (HRHES) for a specified consumer demand. Within this approach, a worst-case scenario from the financial competitiveness analysis has been used to demonstrate that initial sizing of a HRHES can be achieved with only two input data, namely – the available renewable resource and the load profile. The effect of the electrolyser thermal transients at start-up on the overall quantity of hydrogen produced (and accordingly the energy stored), when operated in conjunction with an intermittent renewable generation source, has also been modelled. Finally, a mass-transfer simulation model has been developed to investigate the suitability of constrained renewable generation in creating hydrogen for a hydrogen refuelling station.
22
Weldekidan, Ephrem Terefe. "Design of lithium ion conducting porous hybrid materials for the development of solid Li-battery electrolytes." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0707.
Abstract:
Dans ce travail, des matériaux hybrides polymères-silice poreuse sous forme de poudre et de film mince ont été synthétisés et caractérisés. L'étude préliminaire de leurs conductivité ionique Li+ a également été réalisée. Les poudres hybrides ont été synthétisées par voie sol-gel en utilisant des triblocs classiques (Pluronic, P123) et des diblocs copolymères amphiphiles bifonctinels fabriqués en laboratoire comme agents dirigeant la structure (SDA). Dans le premier cas, la modification post-synthétique a été utilisée pour fonctionnaliser la surface des pores de la silice avec du PEO. Dans un second temps, la fonctionnalisation de la surface des pores avec le bloc hydrophile (PEO) a été réalisée par extraction du bloc hydrophobe. Des films de silice avec des mésocanaux ordonnés de manière hexagonale et orientés verticalement ont été synthétisés sur la surface de l'électrode via un procédé d'auto-assemblage électro-assisté dans des conditions hydrodynamiques. Les films formés sont mésoporeux (3 nm de diamètre) et entièrement accessibles. Un film de 660 nm d'épaisseur a été obtenu en 200 secondes. Ce film a été fonctionnalisé avec du PEO puis du sel de lithium par le biais d'une méthode d'imprégnation en solution. La conductivité ionique des matériaux hybrides a été étudiée après la mise en forme de la poudre sous forme de pastille ou de film directement formé à la surface de l'électrode. Les résultats montrent la conductivité des ions Li+ apportée aux matériaux. Les pastilles ont une porosité interparticulaire de 40% et le remplissage avec l’électrolyte polymère a un effet positif sur l’optimisation de la conductivité des pastillesIn this work, porous polymer-silica hybrid materials as a powder and thin film are synthesized and characterized. The preliminary study of their Li+ ionic conductivity properties are carried out as well. Here, the polymer electrolyte is embedded in silica matrix - polymer-in-ceramic approach. The hybrid powders are synthesized through sol-gel using conventional triblock (Pluronic, P123) and laboratory made bifunctional diblock amphiphilic copolymers as structure directing agents (SDA). In the first case, post-synthetic modification is used to functionalize the pore surface of silica with PEO. The second allowed to direct functionalization the pore surface with hydrophilic block (PEO) through extraction of hydrophobic block. Particle-free mesoporous silica films with hexagonally ordered and vertically oriented mesochannels are synthesized on electrode surface via electro-assisted self-assembly method under hydrodynamic condition. The resulting films are mesoporous (a diameter of 3 nm) and fully accessible. A film with thickness of 660 nm was grown in 200 s, and functionalized with PEO and then lithium salt through solution impregnation method. The ionic conductivity properties of hybrids were performed after shaping the powder as a pellet or with the hybrid film directly formed on the electrode surface. The results showed that the Li+ conductivity brought to the materials. The pellets have 40 % interparticle porosity and filling this with polymer electrolyte has positive effect on optimizing conductivity of the pellets (2.0 x 10-7 Scm-1 for 35 % filling and 6.8 x 10-7 Scm-1 for 100% filling at 25 °C)
23
Lancel, Gilles. "Synthèse et caractérisation de membranes hybrides pour la conduction des ions lithium, et application dans les batteries lithium-air à électrolyte aqueux." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066011/document.
Abstract:
La technologie lithium-air à électrolyte aqueux pourrait révolutionner le stockage de l'énergie, mais la protection du lithium métallique par une vitrocéramique conductrice du lithium reste une limitation importante. Cela rend le système plus fragile, limite sa cyclabilité et augmente la chute ohmique. L'objectif de ce travail a été de remplacer cette vitrocéramique par une membrane hybride réalisée par extrusion électro assistée ou electrospinning, qui combine des propriétés d'étanchéité à l'eau, de flexibilité et de conductivité du lithium. La conductivité ionique est apportée par la partie céramique, pour laquelle les matériaux Li1,4Al0,4Ti1,6(PO4)3 (LATP) et Li0,33La0,57TiO3 (LLTO) ont été étudiés. L'étanchéité est assurée par un polymère fluoré. Différentes voies de synthèse des poudres ont été étudiées et comparées en termes de pureté, de microstructure, de surface spécifique et de propriétés électrochimiques. En particulier, des particules de LATP sub-microniques ont été obtenues pour la première fois par chauffage micro-onde, en des temps aussi courts que 2 min. Des membranes ont ensuite été réalisées à partir de suspensions. Dans une seconde approche, un réseau de nanofibres interconnectées et conductrices du lithium a été réalisé par couplage entre la chimie sol-gel et le procédé d'electrospinning. L'imprégnation de ce réseau donne une membrane hybride flexible, conductrice du lithium et étanche à l'eau. Un renforcement mécanique par les fibres inorganiques est observé. Cette approche a été appliquée aux deux matériaux LATP et LLTO. Ce travail ouvre de nombreuses perspectives pour les batteries lithium-air, lithium soufre et lithium-ionAqueous lithium-air batteries could be a revolution in energy storage, but the main limitation is the use of a thick glass-ceramic lithium ionic conductor to isolate the metallic lithium from the aqueous electrolyte. This makes the system more fragile, limits its cyclability and increases ohmic resistance. The aim of this work is to replace the glass-ceramic by a hybrid membrane made by electrospinning, which combines water tightness, flexibility and lithium-ions conductivity. The ionic conductivity is provided by a nanostructured solid electrolyte ceramic: both Li1,4Al0,4Ti1,6(PO4)3 (LATP) and Li0,33La0,57TiO3 (LLTO) were studied. The water tightness is ensured by a fluorinated polymer. Different powders synthesis methods are reported and compared in terms of purity, microstructure, specific surface area and electrochemical properties. Especially, the LATP microwave-assisted synthesis is reported for the first time. Sub-micrometric LATP particles were obtained in times as short as 2 min. The fabrication of hybrid membranes from suspension is then reported. In a second approach, the coupling between sol-gel chemistry and electrospinning made possible the fabrication of a self-standing lithium-conducting network, made of interconnected crystalline nanofibers. After an impregnation step, a flexible, lithium-conducting and watertight hybrid membrane is obtained. A mechanical reinforcement is observed, which is attributed to the inorganic nanofibers. This approach is exposed for both LATP and LLTO solid electrolytes. This work opens new prospects in lithium-air, lithium-sulfur and lithium-ion batteries
24
Wickramaarachchi, Kethaki. "Synthesis of electrolytic manganese dioxide (EMD) and biomass waste-derived carbon for hybrid capacitors." Thesis, Wickramaarachchi, Kethaki (2022) Synthesis of electrolytic manganese dioxide (EMD) and biomass waste-derived carbon for hybrid capacitors. PhD thesis, Murdoch University, 2022. https://researchrepository.murdoch.edu.au/id/eprint/66472/.
Abstract:
Renewable energy (RE) is expected to be the primary energy supplier in the future energy mix. This has created the necessity for low-cost, safe, and reliable energy storage to guarantee a continuous energy supply by the intermittent RE sources. Due to the inbuilt rich chemistry of manganese dioxide (MnO2) and the advantageous characteristics; of low cost, environmentally friendliness, and nontoxic, it can be adapted for a wide range of applications such as biosensors, humidity sensors, catalysts, and so on. Among the different forms of MnO2, electrolytic manganese dioxide (EMD) is well-demanded energy storage material. However, the limitations such as lower capacitance, irreversibility, and cyclability of EMD in comparison with other metal oxides such as cobalt and nickel oxides, have hindered its application in capacitor energy storage, which was one of the focuses of this thesis.
Therefore, this Ph.D. research project aimed at synthesizing modified EMD materials as the positive electrode for hybrid capacitor applications. The modified EMD was coupled with the biomass-derived activated carbon (AC) which is synthesized as the negative electrode to fabricate hybrid capacitors. This Ph.D. research work has contributed to the existing knowledge through the following: 1) synthesizing pristine EMD using galvanostatic electrodeposition and studying its suitability for capacitor applications via experimental and theoretical analysis, 2) biopolymer alginate assisted EMD synthesis and optimization via experimental and computational modeling, 3) studying the effect of varying surfactants to improve the electrochemical characteristics of EMD, 4) synthesis of biomass waste-derived activated carbon and modeling their parameters for capacitance prediction.
The results indicated the challenge and importance of the delicate tailoring of the EMD characteristics for capacitor application. Pristine EMD was synthesized under different electrodeposition experiment conditions by varying applied current density (100, 200, 300 A m-2) and deposition duration (4, 5, 6 h). The electrodeposition was carried out in a low acidic medium electrolytic bath where a lead (Pb) anode and stainless steel (SS) cathode were used. The EMD was deposited on the Pb anode via Mn2+ oxidation to form Mn4+ and its oxide MnO2. The physicochemical and electrochemical characterization of the obtained EMD powder concluded that the material deposited at 200 A m-2 for 5 hours, showing the spindle-like morphology was suitable over others for supercapacitor (SC) application. The pristine EMD at these experimental conditions delivered 98 F g-1 capacitance at 1 mA cm-2 applied current density tested in 2 M NaOH aqueous electrolyte and proved its potential development by modifying its characteristics. Therefore, the pristine EMD was modified by introducing the biopolymer alginic acid crosslinking to improve its electrochemical performance. The alginic acid was added to the electrolytic bath at varying concentrations; 0, 0.1, 0.25, 0.5, and 1 g l-1, to optimize the added bio-polymer amount to maximize the capacitance. At 0.5 g l-1, the pristine EMD morphology was rearranged to a cactus-shaped with flutes. The calculated specific capacitance of the modified EMD was ~5 times higher (487 F g-1) than the pristine EMD. The molecular dynamics simulation results determined the polymer-ion interactions in the electrolytic bath and provided evidence, showing that the alginic acid could act as a template for binding the Mn2+ ions in a relatively ordered manner for the growth of the EMD deposit. 0.42 of pyrolusite and 0.58 of ramsdellite fractions present in the modified material were quantitatively determined using the neutron powder diffraction (NPD) data. The slight increments of the lattice spacing observed in high-resolution transmission electron microscopy (HRTEM) images were well aligned with the NPD results of unit cell volume expansions of the EMD-polymer composite showing the polymer intercalation within the EMD structure influencing its characteristics. At 2 mA cm-2, the fabricated hybrid capacitor delivered 52 F g-1 specific capacitance, 14 Wh g-1 specific energy, 500 W g-1 specific power, and 94 % capacitance retention over 5000 cycles. The results highlighted the importance of the functional molecular structure of the biopolymer alginic acid to produce a binary composite of EMD-polymer as a capacitor material.
Further, the pristine EMD was modified by electrodepositing the MnO2 using surfactant mediated electrolyte solutions. The electrochemical performance of the synthesized EMD in the presence of three novel cationic surfactants was compared with the pristine EMD and the EMD co-deposited with commonly used cetyltrimethylammonium ammonium bromide (C-AB) surfactant. The three surfactants with different molecular structures are Tetradecyltrimethylammonium bromide (T-AB), Didodecyldimethylammonium bromide (D-AB), Benzyldodecyldimethylammonium bromide (B-AB) used at varying concentrations (15, 30, 60 g l-1) in the electrolytic bath. Among the B-AB surfactant at 30 mg l-1, the EMD (EMD/B-AB30) showed the highest capacitance of 602 F g-1 tested at 1 mA cm-2 current density. The molecular dynamics simulation indicated that when the B-AB surfactant was attached to the Pb electrode via electrostatic, Van der Walls interactions, then the nucleation of MnO2 particles occurred surrounding the surfactant molecule. The unique molecular structure influenced the nucleation formation well-ordered, whereas, for pristine EMD, the nucleation was random. The hybrid capacitor comprises the best performed modified EMD (EMD/B-AB30), and biomass waste-derived AC exhibited 91 F g-1 specific capacitance, an outstanding energy density of 32.4 Wh kg-1 for a corresponding power density of 971 W kg-1.
Valorization of the biomass waste, Mango seed husk (MS), and the Grape marc (GM) was carried out by converting the waste into AC for capacitor electrodes. The MS was carbonized, followed by chemical activation using KOH as the activating agent. Activation temperature was varied at 800, 900, 1000, and 1100 °C temperatures, among at 1100 °C highest surface area of 1943 m2 g-1, and the specific capacitance of 135 F g-1 was obtained for the MS-AC. The MS-AC experimental data were incorporated in four machine learning (ML) algorithms; linear regression (LR), decision tree (DT), support vector regression (SVR), and multi-layer perceptron (MLP) for capacitance prediction. Among, the MLP model showed the best correlation (R2 = 0.9868) between the experimental and predicted capacitance values and proved its potential application for computing the complex non-linear relationships between the input and output datasets. Further, the porous carbon materials were derived from GM using four synthesis routes by varying the parameters of activating agent (KOH and ZnCl2), dopant (Nitrogen), and carbonization (450, 600 °C) and activation (450, 800 °C) temperatures. Among the different GM-AC products, the GM carbon, doped with urea and activated by KOH (KACurea), exhibited better morphology, hierarchical pore structure, larger surface area (1356 m2 g-1), and the highest specific capacitance of 139 F g-1 in 2 M NaOH aqueous electrolyte. The miscellaneous collection of datasets based on AC experiments was used for specific capacitance and power prediction using the MLP ML model.
Overall, this thesis showed that the EMD could be produced in bulk to be used for hybrid capacitor applications. Particularly, it provided insights about the specie interactions in the electrolyte solution that improved the material performance. This built the platform for further studies on altering the additive concentrations and combinations for developing high-performing EMD materials. This Ph.D. work also highlighted the opportunities to valorize the biomass waste to produce AC with desired characteristics of hierarchical pore structure, larger surface area, etc., to replace the conventional AC electrodes. Finally, the electrochemical performance of the hybrid capacitor fabricated using best performed EMD material (EMD/B-AB30) and biomass-waste derived AC (MS-AC 1100) surpassed the energy density values of the existing supercapacitors, proving its potential development in commercial applications.
25
Martín, Dalmas Joël. "Modélisation multi-échelle du transport du lithium dans des électrolytes Li-ion solides et hybrides et leurs interfaces." Electronic Thesis or Diss., Université Grenoble Alpes, 2023. http://www.theses.fr/2023GRALY098.
Abstract:
Les électrolytes solides hybrides (HSE) offrent une alternative prometteuse aux électrolytes liquides classiques dans les batteries Li-ion. Ils intègrent des charges céramiques, souvent sous forme de nanoparticules, dans les électrolytes polymères pour résoudre le principal défi des électrolytes polymères solides (SPE) : leur conductivité réduite par rapport aux alternatives telles que les électrolytes liquides ou céramiques. Cependant, l'impact de l'ajout de charges céramiques aux SPE purs reste incertain. La littérature présente deux ensembles de résultats distincts. Le premier, provenant principalement de recherches expérimentales menées il y a deux décennies, préconise une nette amélioration de la conductivité des SPE grâce à l'intégration de charges céramiques passives telles que la silice ou l'alumine, à diverses concentrations et températures. En revanche, une perspective opposée met en évidence des résultats défavorables des céramiques sur la mobilité ionique au sein des SPE, en particulier lorsque le polymère est à l'état amorphe.Cette thèse vise à répondre à la question cruciale : l'inclusion de nanoparticules céramiques dans les électrolytes polymères solides améliore-t-elle ou entrave-t-elle la mobilité ionique ? Nous utilisons des simulations de dynamique moléculaire pour analyser deux systèmes hybrides composés de Polyéthylène Oxide (PEO) comme polymère, LiTFSI comme sel de lithium, et de silice ou d'alumine comme composants céramiques. Nos simulations explorent les comportements dynamiques et les interactions de ces matériaux sur des échelles de temps prolongées, jusqu'à plusieurs dizaines de nanosecondes, avec le champ de force OPLS-AA. Les paramètres du champ de force sont soigneusement examinés à partir de diverses sources littéraires, chacune ayant été validée individuellement par comparaison avec des données expérimentales.Nous analysons leurs propriétés structurales, examinant leur corrélation avec le comportement dynamique des ions. Cette analyse fournit un compte rendu détaillé des variations dans la dynamique du système. Nos résultats montrent une grande précision en reproduisant le comportement dépendant de la température observé dans les études expérimentales des SPE purs. De plus, nos simulations reproduisent fidèlement les mécanismes de solvatation du sel dans le PEO, validant ainsi nos conclusions pour les SPE purs.Nos résultats concernant l'utilisation de nanoparticules de silice révèlent une réduction substantielle de la conductivité, indépendamment de la concentration ionique. Cette réduction peut en grande partie s'expliquer par l'équation de diffusion, car l'espace occupé par les nanoparticules devient inactif et incapable de soutenir la diffusion ionique, perturbant le mouvement des ions. Nous identifions deux régimes de concentration : un au-dessus et un en dessous d'une concentration seuil de 2 mol/L, correspondant au point de conductivité maximale. Ces régimes présentent des distributions ioniques contrastées et des propriétés de coordination parmi les espèces. Dans le régime de faible concentration, les ions lithium sont principalement couplés aux atomes d'oxygène du PEO, conduisant à sa saturation à 2 mol/L. Dans le second régime, l'excès d'ions lithium interagit avec les anions TFSI, influençant les interactions entre les autres ions du système.L'absence d'amélioration de la conductivité dans nos simulations concorde avec les mesures expérimentales récentes, à l'inverse des rapports antérieurs sur les électrolytes hybrides céramique/polyéthylène-oxyde. Des résultats similaires sont observés dans nos simulations pour les nanoparticules d'alumine. Même avec des paramètres de champ de force modifiés, nos simulations indiquent constamment une réduction de la conductivité lors de l'ajout de nanoparticules d'alumineHybrid Solid Electrolytes (HSEs) offer a promising alternative to conventional liquid electrolytes in the field of Li-ion batteries. These HSEs incorporate ceramic fillers, typically in nanoparticle form, into polymeric electrolytes. This integration aims to address the primary challenge encountered by Solid Polymeric Electrolytes (SPEs): their lower conductivity when compared to alternatives such as liquid or ceramic electrolytes. However, it remains uncertain whether the addition of ceramic fillers to pure SPEs yields a positive impact. The literature presents two distinct sets of findings. The first, stemming from early experimental research conducted two decades ago, advocates a significant improvement in SPE conductivity through the incorporation of passive ceramic fillers such as silica or alumina across various concentrations and temperatures. Conversely, an opposing perspective has emerged, highlighting outcomes that demonstrate an adverse effect of ceramics on the ionic mobility within SPEs, particularly when the polymer is in its amorphous phase.The ongoing debate in this field calls for a needed clarification. In this thesis, we seek to provide answers to a critical question: Does the inclusion of ceramic nanoparticles in Solid Polymeric Electrolytes enhance or impede ion mobility? To address this inquiry, we employ molecular dynamics simulation techniques to analyze two hybrid systems comprised of Polyethylene Oxide (PEO) as the polymer, LiTFSI as the lithium salt, and either silica or alumina as the ceramic components. Our approach involves classical molecular dynamics simulations using the OPLS-AA force field, enabling us to explore the dynamic behaviors and interactions of these materials over extended time scales, typically spanning tenths of nanoseconds. The force field parameters are examinated from various literature sources, each having undergone individual validation through comparisons with experimental data.We carried out an analysis of their structural properties, closely examining their correlation with the dynamic behavior of ions. This analysis provides a detailed account of the shifts in the system's dynamics.Our results demonstrate a high precision in replicating the temperature-dependent behavior observed in experimental studies of pure SPEs. Moreover, our simulations reproduce the solvation mechanisms of the salt on PEO, serving as a robust validation of our findings for pure SPEs.Our findings concerning the use of silica nanoparticles reveal a substantial reduction in conductivity upon their addition, regardless of the ionic concentration. Most of this reduction can be accounted for by the diffusion equation, resulting from the fact that the space occupied by the nanoparticles is made inactive and unable to sustain ionic diffusion, interupting the movement of the ions. We identify two distinct concentration regimes: one above and one below a threshold concentration of 2 mol/L, which coincides with the point of maximum conductivity. These regimes exhibit contrasting ionic distributions and coordination properties among species. In the low-concentration regime, lithium ions are predominantly coupled to oxygen atoms within the PEO, leading to its saturation at 2 mol/L. In the second regime, the surplus of lithium ions interacts with TFSI anions, influencing interactions among other ions in the system.The absence of conductivity enhancement observed in our simulations aligns with recent experimental measurements, contrary to earlier reports on hybrid ceramic/polyethylene-oxide electrolytes. Similar outcomes are evident in our results for alumina nanoparticles. In the specific case of alumina nanoparticles, we explored the utilization of a new set of force field parameters, resulting in significant alterations in the internal organization of the electrolyte. Despite these variations, our simulations consistently indicate a reduction in conductivity upon the addition of alumina nanoparticles
26
Gu, Yu. "A PVDF-BASED HYBRID ELECTROLYTE INCORPORATING LATP AND Al2O3 FILLERS WITH ENHANCED IONIC CONDUCTIVITY AND THERMAL STABILITY FOR LI-ION BATTERIES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1618903524872759.
27
Klett, Matilda. "Electrochemical Studies of Aging in Lithium-Ion Batteries." Doctoral thesis, KTH, Tillämpad elektrokemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145057.
Abstract:
Lithium-ion batteries are today finding use in automobiles aiming at reducing fuel consumption and emissions within transportation. The requirements on batteries used in vehicles are high regarding performance and lifetime, and a better understanding of the interior processes that dictate energy and power capabilities is a key to strategic development. This thesis concerns aging in lithium-ion cells using electrochemical tools to characterize electrode and electrolyte properties that affect performance and performance loss in the cells. A central difficulty regarding battery aging is to manage the coupled effects of temperature and cycling conditions on the various degradation processes that determine the lifetime of a cell. In this thesis, post-mortem analyses on harvested electrode samples from small pouch cells and larger cylindrical cells aged under different conditions form the basis of aging evaluation. The characterization is focused on electrochemical impedance spectroscopy (EIS) measurements and physics-based EIS modeling supported by several material characterization techniques to investigate degradation in terms of properties that directly affect performance. The results suggest that increased temperature alter electrode degradation and limitations relate in several cases to electrolyte transport. Variations in electrode properties sampled from different locations in the cylindrical cells show that temperature and current distributions from cycling cause uneven material utilization and aging, in several dimensions. The correlation between cell performance and localized utilization/degradation is an important aspect in meeting the challenges of battery aging in vehicle applications. The use of in-situ nuclear magnetic resonance (NMR) imaging to directly capture the development of concentration gradients in a battery electrolyte during operation is successfully demonstrated. The salt diffusion coefficient and transport number for a sample electrolyte are obtained from Li+ concentration profiles using a physics-based mass-transport model. The method allows visualization of performance limitations and can be a useful tool in the study of electrochemical systems.QC 20140512
28
Sundaresan, Meenakshi. "A thermal model to evaluate sub-freezing startup for a direct hydrogen hybrid fuel cell vehicle polymer electrolyte fuel cell stack and system /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
29
Zhou, Tao. "Commande et supervision énergétique d’un générateur hybride actif éolien incluant du stockage sous forme d’hydrogène et des super-condensateurs pour l’intégration dans le système électrique d’un micro réseau." Thesis, Ecole centrale de Lille, 2009. http://www.theses.fr/2009ECLI0010/document.
Abstract:
Un système hybride multi-source est étudié dans cette thèse pour la génération dispersée basée sur des sources d’énergie renouvelable et des systèmes de stockage d’énergie. Il comprend un générateur éolien comme source d’énergie primaire, des super-condensateurs comme système de stockage à dynamique rapide, des piles à combustible et des électrolyseurs comme système de stockage sur le long terme sous forme d’hydrogène. Ils sont tous connectés à un bus continu commun et un onduleur est utilisé pour la connexion du système entier au réseau. Dans ce mémoire, nous avons présenté la modélisation du système, la conception du contrôle y compris des stratégies de répartition des flux de puissance et la gestion énergétique. Cette centrale hybride peut finalement générer des puissances lissées et contrôlables comme la plupart des générateurs classiques. Les performances ont été testées en simulation numérique et aussi sur un prototype expérimental. Les contributions scientifiques principales de cette thèse sont les suivantes : l’utilisation et l’adaptation des formalismes pour la modélisation des systèmes complexes et la conception de leur commande ; la conception et la réalisation expérimentale des émulateurs pour réduire le temps et le cout du développement du prototype expérimental ; la proposition et la validation de deux stratégies de gestion des puissances pour la régulation du bus continu et le contrôle des puissances transitées au réseau et enfin la proposition des stratégies de supervision énergétique avec la définition des modes de fonctionnement pour le générateur actif éolien afin d’assurer une disponibilité énergétiqueA hybrid power system is studied in this thesis for the distributed generation based on renewable energy resources and energy storage systems in microgrid applications. It consists of a wind generator as primary energy source, super-capacitors as fast-dynamic storage system, fuel cells and electrolyzers as long-term storage system in hydrogen. They are all connected to a common DC bus and an inverter is used for the connection of the whole system to the grid. In this thesis, we have presented the system modeling, the control design including the power balancing and energy management strategies. This hybrid power system can finally supply controllable smooth powers as most conventional power plants. The performances have been tested in numerical simulations and also on an experimental test bench. As result, it is able to provide ancillary services to the microgrid. The main scientific contributions of this thesis are: the use and the adaptation of the graphical tools for the modeling of complex systems and their design; the design and the experimental implementation of real-time emulators in order to reduce the time and the cost of an experimental platform; the proposition and the validation of two power balancing strategies for the DC-bus voltage regulation and the grid power control and finally the proposition of energy management strategies for the active wind generator to ensure the energy availability
30
Lancel, Gilles. "Synthèse et caractérisation de membranes hybrides pour la conduction des ions lithium, et application dans les batteries lithium-air à électrolyte aqueux." Electronic Thesis or Diss., Paris 6, 2016. http://www.theses.fr/2016PA066011.
Abstract:
La technologie lithium-air à électrolyte aqueux pourrait révolutionner le stockage de l'énergie, mais la protection du lithium métallique par une vitrocéramique conductrice du lithium reste une limitation importante. Cela rend le système plus fragile, limite sa cyclabilité et augmente la chute ohmique. L'objectif de ce travail a été de remplacer cette vitrocéramique par une membrane hybride réalisée par extrusion électro assistée ou electrospinning, qui combine des propriétés d'étanchéité à l'eau, de flexibilité et de conductivité du lithium. La conductivité ionique est apportée par la partie céramique, pour laquelle les matériaux Li1,4Al0,4Ti1,6(PO4)3 (LATP) et Li0,33La0,57TiO3 (LLTO) ont été étudiés. L'étanchéité est assurée par un polymère fluoré. Différentes voies de synthèse des poudres ont été étudiées et comparées en termes de pureté, de microstructure, de surface spécifique et de propriétés électrochimiques. En particulier, des particules de LATP sub-microniques ont été obtenues pour la première fois par chauffage micro-onde, en des temps aussi courts que 2 min. Des membranes ont ensuite été réalisées à partir de suspensions. Dans une seconde approche, un réseau de nanofibres interconnectées et conductrices du lithium a été réalisé par couplage entre la chimie sol-gel et le procédé d'electrospinning. L'imprégnation de ce réseau donne une membrane hybride flexible, conductrice du lithium et étanche à l'eau. Un renforcement mécanique par les fibres inorganiques est observé. Cette approche a été appliquée aux deux matériaux LATP et LLTO. Ce travail ouvre de nombreuses perspectives pour les batteries lithium-air, lithium soufre et lithium-ionAqueous lithium-air batteries could be a revolution in energy storage, but the main limitation is the use of a thick glass-ceramic lithium ionic conductor to isolate the metallic lithium from the aqueous electrolyte. This makes the system more fragile, limits its cyclability and increases ohmic resistance. The aim of this work is to replace the glass-ceramic by a hybrid membrane made by electrospinning, which combines water tightness, flexibility and lithium-ions conductivity. The ionic conductivity is provided by a nanostructured solid electrolyte ceramic: both Li1,4Al0,4Ti1,6(PO4)3 (LATP) and Li0,33La0,57TiO3 (LLTO) were studied. The water tightness is ensured by a fluorinated polymer. Different powders synthesis methods are reported and compared in terms of purity, microstructure, specific surface area and electrochemical properties. Especially, the LATP microwave-assisted synthesis is reported for the first time. Sub-micrometric LATP particles were obtained in times as short as 2 min. The fabrication of hybrid membranes from suspension is then reported. In a second approach, the coupling between sol-gel chemistry and electrospinning made possible the fabrication of a self-standing lithium-conducting network, made of interconnected crystalline nanofibers. After an impregnation step, a flexible, lithium-conducting and watertight hybrid membrane is obtained. A mechanical reinforcement is observed, which is attributed to the inorganic nanofibers. This approach is exposed for both LATP and LLTO solid electrolytes. This work opens new prospects in lithium-air, lithium-sulfur and lithium-ion batteries
31
Nyman, Andreas. "An Experimental and Theoretical Study of the Mass Transport in Lithium-Ion Battery Electrolytes." Doctoral thesis, KTH, Tillämpad elektrokemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-29121.
Abstract:
Lithium‐ion batteries are particularly suitable as energy storage solutions in high power applications, such as hybrid electric vehicles. It is generally considered that one of the processes that limit the power density for lithium‐ion batteries is the mass transport in the electrolyte. Yet, it is still difficult to find a set of properties that fully describe the mass transport for the most common electrolytes. In this work, characterization studies of the mass transport were undertaken for two technically important lithium‐ion battery electrolytes: (1) a liquid electrolyte which consist of LiPF6 dissolved in ethyl methyl carbonate (EMC) and ethylene carbonate (EC) and, (2) a gel electrolyte which consists of LiPF6 dissolved in ethylene carbonate, propylene carbonate (PC) and poly(vinylidenefluoride‐hexafluoropropylene) (P(VdFHFP)).The mass transport in the electrolytes was characterized by combining several experiments. The Maxwell‐Stefan equation was used as basis for the characterization. Models of the transport were formulated from the equation and the apparent transport properties were identified. The characterization methods were first analyzed mathematically in order to establish at which conditions the characterization experiments should be performed. The values of the apparent transport properties were then obtained by optimizing the models to the experimental responses. In order to give the characterization results a comprehensible interpretation and to allow benchmarking of electrolytes, the concept of a normalized potential gradient was introduced.The characterization results of the liquid electrolyte were used in a full cell model of a LiNi0.8Co0.15Al0.05O2 | LiPF6 EC:EMC (3:7) | MAG‐10 cell. The model was developed to analyze the mass transport during a hybrid pulse power characterization (HPPC) test. The analysis was made with a method where the polarization was split up into parts each associated with a process within the cell. The optimum composition in terms of mass transport was found to lie between 0.5 and 1.2 mol/dm3 LiPF6 for the liquid electrolyte and between 5 and 7 wt. % LiPF6 for the gel electrolyte. Less amount of polymer in the gel electrolyte gave a faster mass transport. It was also found that the mass transport in the liquid electrolyte contributed to a major part of the polarization during HPPC tests.Litiumjonbatterier är speciellt lämpliga som ackumulatorer i högeffektsapplikationer som elhybridfordon. Det är idag allmänt accepterat att en av processerna som begränsar effekttätheten för litiumjonbatterier är masstransporten i elektrolyten. Trots detta är det fortfarande svårt att få tag på data som fullständigt beskriver masstransporten i de vanligaste elektrolyterna. I det här arbetet har masstransportkarakteriseringar gjorts för två tekniskt viktiga elektrolyter: (1) en vätskeelektrolyt som består av LiPF6 upplöst i etylenkarbonat (EC) och etylmetylkarbonat (EMC), och (2) en gel elektrolyt som består av LiPF6 upplöst i EC, propylenkarbonat (PC) och poly(vinylidene fluoride‐hexafluoro propylene) (P(VdFHFP)). Masstransporten i elektrolyterna karakteriserades genom att kombinera ett antal karakteriseringsexperiment. Maxwell‐Stefans ekvation användes som utgångspunkt i karakteriseringarna. Modeller av transporten formulerades från ekvationen och de effektiva transportegenskaperna identifierades. En matematisk analys gjordes först av karakteriseringstekniken, så att det kunde fastslås för vilka förhållanden experimenten skulle utföras. Värderna av transportegenskaperna erhölls genom att optimera modellerna till det experimentella beteendet. För att ge karakteriseringsresultaten en begriplig tolkning och för att kunna mäta prestandan av elektrolyter, infördes konceptet normaliserad potentialgradient. Resultatet från karakteriseringen av vätskeelektrolyten användes i en model av en LiNi0.8Co0.15Al0.05O2 | LiPF6 EC:EMC (3:7) | MAG‐10 cell. Modellen utvecklades för att analysera masstransporten i cellen under ett hybridpulstest (HPPC). Analysen gjordes med en metod där polarisationen delades upp i delar som var och en var kopplad till en process i batteriet. Den optimala sammansättningen med avseende på masstransporten låg i regionen 0.5–1.2 mol/dm3 LiPF6 för vätskeelektrolyten och 5‐7 vikt% LiPF6 för gelelektrolyten. Mindre mängd polymer i gelelektrolyten gav en snabbare masstransport. Det konstaterades också att masstransporten i vätskeelektrolyten bidrog med en av de största delarna till polarisationen i HPPC testen.
QC 20110128
32
Baumann, Lars. "Improved system models for building-integrated hybrid renewable energy systems with advanced storage : a combined experimental and simulation approach." Thesis, De Montfort University, 2015. http://hdl.handle.net/2086/11103.
Abstract:
The domestic sector will play an important role in the decarbonisation and decentralisation of the energy sector in the future. Installation numbers of building-integrated small-scale energy systems such as photovoltaics (PV), wind turbines and micro-combined heat and power (CHP) have significantly increased. However, the power output of PV and wind turbines is inherently linked to weather conditions; thus, the injected power into the public grid can be highly intermittent. With the increasing share of renewable energy at all voltage levels challenges arise in terms of power stability and quality. To overcome the volatility of such energy sources, storage technologies can be applied to temporarily decouple power generation from power consumption. Two emerging storage technologies which can be applied at residential level are hydrogen systems and vanadium-redox-flow-batteries (VRFB). In addition, the building-integrated energy sources and storage system can be combined to form a hybrid renewable energy system (HRES) to manage the energy flow more efficiently. The main focus of this thesis is to investigate the dynamic performance of two emerging energy storage technologies, a hydrogen loop composed of alkaline electrolyser, gas storage and proton exchange membrane (PEM) fuel cell, and a VRFB. In addition, the application of building-integrated HRES at customer level to increase the self-consumption of the onsite generated electricity and to lower the grid interaction of the building has been analysed. The first part deals with the development of a research test-bed known as the Hybrid Renewable Energy Park (HREP). The HREP is a residential-scale distributed energy system that comprises photovoltaic, wind turbine, CHP, lead acid batteries, PEM fuel cell, alkaline electrolyser and VRFB. In addition, it is equipped with programmable electronic loads to emulate different energy consumption patterns and a charging point for electric vehicles. Because of its modular structure different combinations of energy systems can be investigated and it can be easily extended. A unified communication channel based on the local operating network (LON) has been established to coordinate and control the HREP. Information from the energy systems is gathered with a temporal resolution of one second. Integration issues encountered during the integration process have been addressed. The second part presents an experimental methodology to assess the steady state and dynamic performance of the electrolyser, the fuel cell and the VRFB. Operational constrains such as minimum input/output power or start-up times were extracted from the experiments. The response of the energy systems to single and multiple dynamic events was analysed, too. The results show that there are temporal limits for each energy system, which affect its response to a sudden load change or the ability to follow a load profile. Obstacles arise in terms of temporal delays mainly caused by the distributed communication system and should be considered when operating or simulating a HRES at system level. The third part shows how improved system models of each component can be developed using the findings from the experiments. System models presented in the literature have the shortcoming that operational aspects are not adequately addressed. For example, it is commonly assumed that energy systems at system level can respond to load variations almost instantaneously. Thus, component models were developed in an integrated manner to combine theoretical and operational aspects. A generic model layout was defined containing several subsystems, which enables an easy implementation into an overall simulation model in MATLAB®/Simulink®. Experimental methods were explained to extract the new parameters of the semi-empirical models and discrete operational aspects were modelled using Stateflow®, a graphical tool to formulate statechart diagrams. All system models were validated using measured data from the experimental analysis. The results show a low mean-absolute-percentage-error (<3%). Furthermore, an advanced energy management strategy has been developed to coordinate and to control the energy systems by combining three mechanisms; statechart diagrams, double exponential smoothing and frequency decoupling. The last part deals with the evaluation, operation and control of HRES in the light of the improved system models and the energy management strategy. Various simulated case studies were defined to assess a building-integrated HRES on an annual basis. Results show that the overall performance of the hydrogen loop can be improved by limiting the operational window and by reducing the dynamic operation. The capability to capture the waste heat from the electrolyser to supply hot water to the residence as a means of increasing the overall system efficiency was also determined. Finally, the energy management strategy was demonstrated by real-time experiments with the HREP and the dynamic performance of the combined operation has been evaluated. The presented results of the detailed experimental study to characterise the hydrogen loop and the VRFB as well as the developed system models revealed valuable information about their dynamic operation at system level. These findings have relevance to the future application and for simulation studies of building-integrated HRES. There are still integration aspects which need to be addressed in the future to overcome the proprietary problem of the control systems. The innovations in the HREP provide an advanced platform for future investigations such as electric-vehicles as decentralised mobile storage and the development of more advanced control approaches.
33
Gailly, Frédéric. "Alimentation électrique d'un site isolé à partir d'un générateur photovoltaïque associé à un tandem électrolyseur/pile à combustible (batterie H2/O2)." Phd thesis, Toulouse, INPT, 2011. http://oatao.univ-toulouse.fr/11527/1/Gailly_Frederic.pdf.
Abstract:
Les systèmes à énergies renouvelables couplés à un stockage hydrogène apportent des solutions nouvelles et innovantes à l'alimentation électrique des milieux peu ou non électrifiés. Le concept de batterie H2 qui équipe ce type de système est une forme de stockage originale qui apporte l'autonomie et l'indépendance électrique pour des longues durées (typiquement stockage saisonnier). Le fonctionnement de cette batterie H2 est le suivant : un électrolyseur produit des gaz (H2 et O2) avec les surplus d'énergie de la source renouvelable ; l'hydrogène, voire l'oxygène, est ensuite stocké dans des réservoirs pour être utilisé ultérieurement grâce à une pile à combustible lorsque la source renouvelable est insuffisante. Dans cette étude, nous nous intéresserons spécifiquement au couplage entre des générateurs photovoltaïques avec une batterie H2/O2 pour l'alimentation d'un site isolé sans interruption. Ces travaux de recherche s'inscrivent dans le projet ANR PEPITE (ANR-PanH 2007-2012) et ont été menés en partenariat avec HELION Hydrogen Power, le CEA Liten et l'Université de Corse. Le projet est également labellisé par les pôles de compétitivité CAPENERGIES et TENERRDIS. Tout d'abord, une réflexion générale s'appuyant sur les propriétés d'une batterie H2/O2 démontre la nécessité d'introduire une batterie (ici au plomb) pour garantir un fonctionnement instantané et sans interruption. Puis, une étude qualitative sur les architectures électriques possibles (bus de tension DC, AC…) a été menée pour s'achever sur une étude quantitative réalisée spécifiquement pour le projet PEPITE. Parallèlement à cela, différentes stratégies de gestions énergétiques ont été proposées afin d'utiliser les deux stockages dans les meilleures conditions, de limiter leur vieillissement ainsi que les pertes. Deux bancs d'essais à échelle réduite (un premier à bus DC et un second à bus AC) ont été réalisés au sein du laboratoire LAPLACE afin de valider les études et de préparer le prototype final qui sera testé sur le site de HELION Hydrogen Power au cours de l'été 2011.
34
Tabanjat, Abdulkader. "Modélisation, commande et supervision d'un système multi-sources connecté au réseau avec stockage tampon de l'énergie électrique via le vecteur hydrogène." Thesis, Belfort-Montbéliard, 2015. http://www.theses.fr/2015BELF0266/document.
Abstract:
Les réserves limitées de combustibles fossiles et la pollution entrainée par les gaz produits ouvrent la voie à desressources énergétiques renouvelables (RER) alternatives et prometteuses telles que les ressources solaires (RS)et les ressources éoliennes (RE). Ces ressources sont librement disponibles et respectueuses de l'environnement.Cependant, les RER sont de nature intermittente. Par conséquent, il existe un besoin de lissage des fluctuations depuissance en stockant l'énergie pendant les périodes de surproduction pour la restituer au réseau lorsque lademande énergétique devient importante. Les systèmes de stockage de l'énergie (SSE) peuvent alors être utilisésde manière appropriée à cette fin.L'utilisation de plusieurs sources d'énergie et de stockeurs pour construire des systèmes de puissance hybrides(SPH) exige une stratégie de gestion de l'énergie pour atteindre le minimum de coût des SPH et un équilibre entrela production et la consommation de l'énergie. Cette méthode de gestion de l'énergie est un mécanisme pourobtenir une production d'énergie idéale et pour satisfaire convenablement la demande de charge à rendementrelativement élevé.Dans cette thèse, un SPH intégrant production électrique photovoltaïque, éolienne, une micro-turbine à gaz ainsiqu'un système de stockage de l'électricité par le vecteur hydrogène est considéré. Le but de cette hybridation estde construire un système fiable, qui est en mesure de fournir la charge et qui a la capacité de stocker l'énergieexcédentaire sous forme hydrogène et de la réutiliser plus tard. En outre, le problème d'ombrage partiel dePanneaux Photovoltaïques est étudié de manière approfondie. Une nouvelle solution basée sur des interrupteurssimples et un contrôle par logique floue intégré dans une carte électronique dSPACE a été proposée. Unereconfiguration des panneaux photovoltaïques en temps réel et de déconnexion de ceux ombragés est égalementeffectuée en cherchant à minimiser les pertes de puissance. Le couplage thermique entre ces panneauxphotovoltaïques et un électrolyseur à membrane polymère est également étudié, à l'échelle système. Enrécupérant une partie de l'énergie thermique reçue par les panneaux, une amélioration du rendement du systèmehybride PPVELS MEP est réaliséeThe limited reserves of fossil fuel and the pollution gases produced pave the way to promising alternativeRenewable Energy Sources (RESs) such as Solar Energy Sources (SESs) and Wind Energy Sources (WESs).SESs and WESs are freely available and environmentally friendly. However, RESs are intermittent in nature.Therefore, the smoothing of power fluctuations by storing the energy during periods of oversupply and restore it tothe grid when demand becomes necessary. Accordingly, Energy Storage Systems (ESSs) can be appropriatelyused for this purpose.Using several energy sources for constructing HPSs alongside with ESS will require an energy managementstrategy to achieve minimum HPS cost and optimal balance between energy generation and energy consumption.This energy management method is a mechanism to achieve an ideal energy production and to conveniently satisfythe load demand at relatively high efficiency.In this thesis, a Hybrid Power System (HPS) including Renewable Energy Sources (RESs) such as main sourcescombined with Gas Micro-Turbine (GMT) and hydrogen storage system such as Back-up Sources (BKUSs) hasbeen presented. The aim of this hybridization is to build a reliable system, which is able to supply the load andhaving the ability to store the excess energy in hydrogen form and reuse it later when demanded. Consequently, thestored energy at the end of each cycle will be zero and a minimum generated power cost is achieved. In addition,partial shading problem of Photovoltaic (PV) panels is comprehensively studied and a new solution based on simpleswitches and Fuzzy Logic Control (FLC) integrated into dSPACE electronic card is created. Consequently, a realtime PV panels reconfiguration and disconnecting shaded ones is performed and minimum power losses isachieved. Then, the PV panels are connected to a Proton Exchange Membrane Electrolyser (PEM ELS). Theemitted temperature by the PV panels is transferred to the endothermic element PEM ELS. Consequently, anefficiency enhancement of the hybrid system PVPEM ELS is realized
35
Hibino, Takashi, Atsuko Tomita, Mitsuru Sano, Toshio Kamiya, Masahiro Nagao, and Pilwon Heo. "Sn0.9In0.1P2O7-Based Organic/Inorganic Composite Membranes : Application to Intermediate-Temperature Fuel Cells." The Electrochemical Society, 2007. http://hdl.handle.net/2237/18430.
36
Ndipingwi, Miranda Mengwi. "Graphol and vanadia-linkedzink-doped lithium manganese silicate nanoarchitectonic platforms for supercapatteries." University of Western cape, 2020. http://hdl.handle.net/11394/7236.
Abstract:
Philosophiae Doctor - PhDEnergy storage technologies are rapidly being developed due to the increased awareness of global warming and growing reliance of society on renewable energy sources. Among various electrochemical energy storage technologies, high power supercapacitors and lithium ion batteries with excellent energy density stand out in terms of their flexibility and scalability. However, supercapacitors are handicapped by low energy density and batteries lag behind in power. Supercapatteries have emerged as hybrid devices which synergize the merits of supercapacitors and batteries with the likelihood of becoming the ultimate power sources for multi-function electronic equipment and electric/hybrid vehicles in the future. But the need for new and advanced electrodes is key to enhancing the performance of supercapatteries. Leading-edge technologies in material design such as nanoarchitectonics become very relevant in this regard. This work involves the preparation of vanadium pentoxide (V2O5), pristine and zinc doped lithium manganese silicate (Li2MnSiO4) nanoarchitectures as well as their composites with hydroxylated graphene (G-ol) and carbon nanotubes (CNT).
2023-12-01
37
Barakat, Mahmoud. "Development of models for inegrating renewables and energy storage components in smart grid applications." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC217/document.
Abstract:
Cette thèse présente un modèle unique du MASG (Modèle d’Architecture du Smart Grid) en considérant l 'état de l’art des différentes directives de recherche du smart grid. Le système hybride de génération d'énergie active marine-hydrogène a été modélisé pour représenter la couche de composants du MASG. Le système intègre l'électrolyseur à membrane d’échange de proton (à l’échelle de méga watt) et les systèmes de piles à combustible en tant que composants principaux du bilan énergétique. La batterie LiFePO4 est utilisée pour couvrir la dynamique rapide de l'énergie électrique. En outre, la thèse analyse le système de gestion de l'énergie centralisé et décentralisé. Le système multi-agents représente le paradigme du système décentralisé. La plate-forme JADE est utilisée pour développer le système multi-agents, en raison de son domaine d'application général, de ses logiciels à licence libre, de son interface avec MATLAB et de sa calculabilité avec les standards de la Fondation des Agents Physiques Intelligentes. Le système de gestion d'énergie basé sur JADE équilibre l'énergie entre la génération (système de conversion d'énergie marine-courant) et la demande (profil de charge résidentielle) pendant les modes de fonctionnement autonome et connecté au réseau. Le modèle proposé du MASG peut être considéré comme une étude de cas pilote qui permet l'analyse détaillée et les applications des différentes directions de recherche du smart gridThis thesis presents a unique model of the SGAM (Smart Grid Architecture Model) with considering the state of the art of the different research directions of the smart grid and. The hybrid marine-hydrogen active power generation system has been modeled to represent the component layer of the SGAM. The system integrates the MW scale PEM electrolyzer and fuel cell systems as the main energy balance components. The LiFePO4 battery is used to cover the fast dynamics of the electrical energy. Moreover, the thesis analyzes the centralized and the decentralized energy management system. The MAS (Multi-Agent Systems) represents the paradigm of the decentralized system. The JADE platform is used to develop the MAS due to its general domain of application, open source and free license software, interface with MATLAB and the computability with the FIPA (Foundation of Intelligent Physical Agent) standards. The JADE based energy management system balances the energy between the generation (marine-current energy conversion system) and the demand side (residential load profile) during the stand-alone and the grid-connected modes of operation. The proposed model of the SGAM can be considered as a pilot case study that enables the detailed analysis and the applications of the different smart grid research directions
38
Sayah, Simon. "Impact de la formulation d'électrolytes sur les performances d'une électrode négative nanocomposite silicium-étain pour batteries Li-ion." Thesis, Tours, 2017. http://www.theses.fr/2017TOUR4025/document.
Abstract:
Ce projet de thèse porte sur la recherche de nouveaux électrolytes et additifs dans le but d’améliorer la cyclabilité d’une électrode négative composite de formule Si0.32Ni0.14Sn0.17Al0.04C0.35 et d’obtenir une interface électrode|électrolyte stable. En effet, comme la plupart des matériaux à base de silicium, ce composite de grande capacité (plus de 600 mA.h.g-1) souffre actuellement d’une faible durée de vie provenant essentiellement des expansions volumiques qu’il subit lors de sa lithiation et de sa SEI défaillante. Deux types d'électrolytes ont été évalués : (i) un mélange de carbonates d’alkyles EC/PC/3DMC auquel a été ajouté un sel de lithium (LiPF6, LiTFSI, LiFSI ou LiDFOB) ainsi que des additifs aidant à la formation de la SEI tels que le carbonate de vinylène (VC) ou le carbonate de fluoroéthylène (FEC), (ii) des liquides ioniques (LI) contenant un cation ammonium quaternaire (N1114+), imidazolium (EMI+) ou pyrrolidinium (PYR+), associé à un anion à charge délocalisée comme le bis(trifluorométhanesulfonyl)amidure (TFSI-) ou le bis(fluorosulfonyl)amidure (FSI-). L’analyse du diagramme d’ionicité de Walden a permis de mettre en évidence la bonne dissociation de LiFSI et LiPF6 dans EC/PC/3DMC assurant ainsi des conductivités ioniques supérieures à 12 mS.cm-1. Bien que possédant des propriétés de transport a priori moins intéressantes dans ce mélange ternaire que les autres sels, LiDFOB forme en réduction une SEI permettant au composite de fournir les meilleures performances en cyclage sans additif avec 560 mA.h.g-1 pour un rendement coulombique de 98,4%. L’ajout d’additif est cependant nécessaire pour atteindre les objectifs fixés par le projet en termes de rendement coulombique (>99,5%). Dans ce cas, l’ajout de 2%VC+10%FEC au mélange ternaire est le plus intéressant avec LiPF6. Le matériau fourni ainsi des capacités de 550 mA.h.g-1 durant une centaine de cycles à un régime de C/5 avec un rendement coulombique de 99,8%. En milieu LI, les performances optimales sont atteintes avec le [EMI][FSI] et 1 mol.L-1 de LiFSI. Le composite atteint alors une capacité de 635 mA.h.g-1 durant 100 cycles à un régime de C/5 avec un rendement coulombique très proche de 100%, tout en s’affranchissant de l’ajout d’additifs. Malgré une viscosité bien plus élevée que celles des mélanges de carbonates d’alkyles, cette formulation permet de générer une SEI plus stable dont la nature, principalement minérale, est issue majoritairement des produits de réduction de FSI-This study focuses on new electrolytes and additives in order to improve the cyclability of a Si0.32Ni0.14Sn0.17Al0.04C0.35 negative composite electrode (Si-Sn) and to obtain a stable electrolyte|electrolyte interface. Indeed, like most silicon-based materials, this high-capacity Si-Sn composite (over 600 mA.hg-1) currently suffers from a short cycle life due to volume expansion during charge-discharge processes leading to the degradation of the SEI. To improve the quality of the interface, two kinds of electrolytes were evaluated: (i) mixtures of alkyl carbonates EC/PC/3DMC in which a lithium salt (LiPF6, LiTFSI, LiFSI or LiDFOB) and additives like SEI builder (vinylene carbonate (VC) or fluoroethylene carbonate (FEC)) were added, (ii) ionic liquids (IL) based on quaternary ammonium (N1114+), imidazolium (EMI+) or pyrrolidinium (PYR+) cation, associated with delocalized charge anions such as bis(trifluoromethanesulfonyl)imide (TFSI-) or bis(fluorosulfonyl)imide (FSI-). The Walden diagram confirms the efficient dissociation of LiFSI and LiPF6 in EC/PC/3DM ensuring ionic conductivities as high as 12 mS.cm-1. Although possessing limited transport properties in such a ternary mixture compared to other salts, LiDFOB forms, without additional additives, an high quality SEI allowing the composite to provide the best performances in half cells (560 mA.hg-1 and 98.4% coulombic efficiency). The use of additive is however necessary to reach the objectives fixed by the ANR research project in terms of coulombic efficiency (>99.5%). In this case, the addition of 2%VC+10%FEC to the ternary mixture is the most interesting composition with LiPF6 as lithium salt. So, the Si-Sn nanocomposite material reaches 550 mA.h.g-1 during 100 cycles at C/5 with 99.8% efficiency. In IL, the best performances are achieved in [EMI][FSI]/LiFSI (1 mol.L-1). The performances of the Si-Sn composite reaches 635 mA.h.g-1 for 100 cycles at C/5 with coulombic efficiency close to 100%, without additives. This electrolyte formulation generates a stable SEI which the mainly mineral composition, is predominantly derived from the reduction products of FSI-
39
Lo, Cheng Hsing, and 羅正欣. "Experimental investigations on PVA/PEO hybrid polymer electrolytes." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/11099861979646423606.
Abstract:
碩士長庚大學
化工與材料工程研究所
91
The alkaline polymer electrolyte membranes containing polyethylene oxide (PEO), polyvinyl alcohol (PVA) and using water as the solvent and potassium hydroxide (KOH) as the salt have been investigated in the present study. These polymer electrolyte membranes were characterized by A.C. impedance spectroscopic techniques. The ionic conductivity of the polymer electrolyte membranes increased with increasing PEO/PVA ratio. Ionic conductivity of these polymer membranes increases from 6.8×10-6 S/cm to 1.12×10-2 S/cm at room temperature when the ratio of PEO:PVA varied from 10:0 to 2:8. Temperature dependence of the conductivity was found to be in agreement with Arrhenius type with activation energy in the range of 2-9 kJ mole-1, depending on the electrolyte compositions. The characterizations of electrolyte properties were carried out on the PEO/PVA hybrid polymer membranes using DSC, SEM, POM, a.c impedance spectroscopic techniques and electrochemical spectroscopic techniques. It was found that the polymer electrolyte membranes exhibited high ionic conductivity, good mechanical property and excellent electrochemical stability.
40
Cardoso, Marita Alves. "Luminescent organic-inorganic hybrid electrolytes for smart building glazing." Doctoral thesis, 2021. http://hdl.handle.net/10773/31524.
Abstract:
There is a global need to improve the building energy generation efficiency in
the new generation of buildings, so called zero-energy buildings (ZEBs). One
strategy includes the development of smart windows based on electrochromic
devices (ECDs) coupled to luminescent layers and luminescent solar
concentrators (LSCs). New materials based on lanthanide complexes with high
quantum efficiency incorporated in appropriate host matrices prepared by solgel
chemistry opens challenging opportunities for the development of new
devices with remarkable electro-optical performance and foreseen application
as smart windows for ZEBs. In this thesis, new electrolytes based on organicinorganic
hybrids doped with an ionic liquid allowed the production of ECDs
with high visible and NIR transparency and voltage-actuated dual coloration
tuning, enabling three-mode operation (bright hot, semi-bright warm, and dark
cold). The ECD delivers a number of extraordinary features, in particular high
switching efficiency and optical modulation, good cycling stability, large
coloration efficiency, excellent optical memory, and unusual self-healing ability
following mechanical stress. In addition, new lanthanide ions (Ln3+ = Nd3+, Eu3+,
Tb3+, Yb3+)-doped surface functionalized ionosilicas (ISs) were produced,
characterized and embedded in poly(methyl methacrylate) yielding transparent
films with negligible self-absorption with potential to be used LDS layers, and
LSC into a single device. The significant absolute increase observed in the PV
cell external quantum efficiency (EQE~32% between 300-360 nm relatively to
the bare PV cell) supports the applicability of the developed materials for ZEBs.Existe uma necessidade global de melhorar a eficiência energética nos edifícios com vista a uma nova geração de edifícios denominados edifícios de balanço energético nulo (ZEBs). Uma das estratégias propostas inclui o desenvolvimento de janelas inteligentes baseadas em dispositivos eletrocrómicos (ECDs) acoplados a camadas luminescentes e concentradores solares luminescentes (LSCs). Novos materiais baseados em complexos de iões lantanídeos com elevado rendimento quântico de emissão incorporados em matrizes hospedeiras apropriadas, preparadas pelo método sol-gel, abrem um leque de oportunidades para o desenvolvimento de novos dispositivos com notável desempenho eletro-ótico para janelas de ZEBs. Nesta tese, novos eletrólitos baseados em híbridos orgânicos-inorgânicos dopados com um líquido iónico luminescente permitiram a produção de ECDs com elevada transparência nas regiões espetrais do visível e NIR e, possibilitando o ajuste fino da passagem de luz solar e da energia solar, permitindo operação em três modos (brilhante quente, semi-brilhante quente, e frio escuro). O ECD oferece uma série de recursos extraordinários, em particular alta eficiência e modulação ótica, boa estabilidade, grande eficiência de coloração, excelente memória ótica e capacidade de auto-regeneração após stress mecânico. Além disso, novas ionossílicas funcionalizadas na superfície dopadas com iões lantanídeos (Ln3+ = Nd3+, Eu3+, Tb3+,Yb3+) foram produzidas, caracterizadas e incorporadas em poli(metil metacrilato) produzindo filmes transparentes com auto-absorção desprezável com potencial aplicação em LDS e LSC. Foi observado um aumento absoluto significativo na eficiência quântica externa da célula PV (EQE ~ 32% entre 300-360 nm em relação à célula PV base) demostrando a aplicabilidade dos materiais desenvolvidos para ZEBs.
Programa Doutoral em Ciência e Engenharia de Materiais
41
Angjeli, Kristina, Carlo Versace, Isabella Nicotera, and Roberto Bartolino. "Hybrid nanostructured fillers for polymer electrolytes in the PEM Fuel Cells." Thesis, 2012. http://hdl.handle.net/10955/1150.
Abstract:
Dottorato di Ricerca in Scienze e Tecnologie delle Mesofasi e dei Materiali Molecolari, XXV Ciclo, a.a. 2011-2012The present thesis is focused on the development of novel nancomposite membranes, prepared by the incorporation of two-dimensional inorganic layered structures such as (i) smectite clays (synthetic and natural), (ii) graphene oxide (GO), and (iii) layered double hydroxides (LDHs) with different compositions into the polymer matrix of Nafion, for use as electrolytes in Proton Exchange Membrane fuel cells. The characteristics of the membranes were studied mainly, in terms of transport properties by NMR spectroscopy, in order to study the water dynamics inside the electrolyte membranes. For this purpose the Pulse-Field-Gradient Spin-Echo NMR (PFGSENMR) method was employed to obtain a direct measurement of water self-diffusion coefficients on the water-swelled membranes in a wide temperature range (25-140 °C). This technique together with the 1H-NMR spectral analysis and NMR spin-lattice relaxation times (T1) conducted under variable temperature. Furthermore, both pristine materials (fillers and Nafion) as well as the resulted nanocomposite membranes were characterized by a combination of X-ray diffraction, FTIR spectroscopy, thermal analysis (DTA/TGA), Raman spectroscopies and scanning electronic microscopy (SEM).
Università della Calabria
42
Chou, Chih-Yu, and 周致羽. "Glyme solvents based on Mg(BH4)2 as electrolyte for magnesium hybrid batteries." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/f4gtn8.
Abstract:
碩士國立中央大學
化學工程與材料工程學系
104
Magnesium is an attractive anode material for secondary batteries because of low cost, low pollution, abundance, high energy density and high safety. However, there are two major obstacle in developing ideal magnesium ion batteries (MIBs). The first one is the formation of passivation layer on the surface due to the high chemical activity of magnesium. This result in restrictions on selecting suitable electrolytes. The other one is the strong coulombic interaction between Mg2+ and the intercalation host, which makes the ion diffusion sluggish, creating a barrier for the development of the cathode materials for MIBs. In this study, MoS2 is chosen as the active material which Mg2+ ion cannot intercalate/deintercalate into the host structure in the presence of APC electrolyte. After adding the lithium salt (LiCl) in the APC electrolyte, the Mg//MoS2 cell starts storing energy and its electrochemical behavior is very similar to MoS2 in lithium-ion battery system. The electrochemical performances significantly increase with the increase of lithium-ion concentration. At low concentration (0.1 M), the cell delivers reversible capacity of 45 mAh/g (at 25 mA/g), whereas at high concentration (0.7 M) the cell delivers superior capacity of 166 mAh/g. Similarly, the cell with high concentration of Li salt showed excellent high rate retention of 64% at 1000 mA/g, whereas the cell with low concentration of Li salt showed poor retention of 31%. The ion mobility is believed to play important role in electrochemical performance. After showing the remarkable benefits of dual-salts electrolyte, it is worth expanding this concept to other electrolytes, which have the nature of high safety and environmental friendliness. Therefore, we introduce Mg(BH4)2 salt and Glyme-based solvents as electrolyte. The present study indicate that substrates, temperature, concentration, solvent and the additive effects the reversibility of Magnesium deposition and dissolution. The study showed addition of LiBH4 and NaBH4 can improve the electrochemical performance of MIBs to a greater extent. To investigate the properties of different dual-salts Mg(BH4)2 (MBH) electrolyte, MoS2/Graphene composite is chosen as the active material. Among them, MBH-diglyme electrolyte delivered highest capacity, whereas MBH-triglyme and MBH-tetraglyme electrolytes showed slightly decreased capacity owing to their high viscosity. Despite the electrochemical performance between MBH and APC electrolyte are similar, MBH electrolyte is expected to replace APC electrolyte for practical application. This study reports the possibility of Na/Mg hybrid battery based on intercalated cathode material for the first time. Compared to lithium-ion and Li/Mg hybrid battery, the high rate retention of Na/Mg hybrid battery is much higher (up to 76%) but the capacity at low current density needs to be further improved. These results provide insight for further development of Na/Mg hybrid battery.
43
Pan, Yu-chi, and 潘育麒. "Structural characterization and dynamic properties of star-like organic-inorganic hybrid electrolytes." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/69131505390397753054.
Abstract:
碩士國立中央大學
化學研究所
96
A sol-gel synthetic route for preparing poly(oxyalkylene) block copolymers has been developed by using 2,4,6-trichloro-1,3,5-triazine (cyanuric chloride, cc) as the coupling core. The coupling reaction involves the selective substitutions of oligo(oxyalkylene)-amines at 0?C, 25?C and 130?C. Afterwards, (3-glycidyloxypropyl)-trimethoxysilane (GLYMO) reacts with the NH2 end groups of oligo(oxyalkylene)amines (Jeffamine-ED serious), and then the Si-OCH3 will condensation with other GLYMO. The effects of several variables on ionic conductivity were investigated, such as length of PEO chain, percentage of EO/PO segment, extent of cross-linking, and salt concentration (LiClO4). Characterization was made by solid-state NMR, Differential scanning calorimetry (DSC), AC-Impedance and IR spectroscopy. The optimal lithium conductivity for the copolymer electrolytes thus obtained reaches 4.3 x 10-5 S/cm at 30?C.
44
Lu, Shao Hao, and 呂紹豪. "Application of flexible composite lithium ion conducting membranes in hybrid electrolyte lithium air batteries." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107CGU05063035%22.&searchmode=basic.
45
Lo, Chieh, and 羅傑. "Studies on LixSnOS Superionic Conductor and its Hybrid Electrolyte for Solid State Lithium Ion Battery." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/2z8wch.
Abstract:
碩士國立臺灣科技大學
材料科學與工程系
106
In recent years, commercially available lithium ion batteries have been mainly produced using organic electrolytes, but the problem of heat and explosion caused by improper use of batteries still continuously occurs. In addition, considering the miniaturization, flexibility and high energy density, the development of flexible all-solid-state lithium batteries is of importance. At present, there are two types of solid electrolyte materials: (1) Inorganic ceramic solid electrolyte and (2) Polymer solid electrolyte thin film. Although inorganic ceramic solid electrolyte membrane can provide the required lithium ion conductivity, there is a problem of rigidity, which cannot be applied to the flexible electronics; the polymer solid electrolyte membrane materials are all conductive macromolecules and can transfer conjugated electrons, but its lithium ion conductivity is not ideal. At present, in terms of research, Li10GeP2S12 and its derivatives Li10MP2X12 (M= Ge; Sn; Si, X=S; Se) and others have shown the good lithium ion conductivity of 10-2 S/cm at room temperature. Unfortunately, this type of sulfides is extremely sensitive to moisture. This study combines the advantages of high Li ion conductivity of sulfides and high chemical stability of oxides to prepare Li-Sn bimetal oxysulfide at different Li:Sn molar ratios to form the Li ion conductor of Li3x[LixSn1-x(O,S)2]. The experimental parameters include the different Li:Sn molar ratios for LixSnOS powders at x= 1, 1.5, 1.8, 2, and 2.2, the different processing temperatures at 500 oC, 550oC, and 600oC, and the different numbers of compensation disks for sulfurization at 0S, 0.5S, 1S, and 1.5S. The best solid electrolyte is the Li2SnOS-550-1S with Li ion conductivity of 1.92×10-4 S/cm, in which Li2SnOS-550-1S means the LixSnOS mixed powder has a Li:Sn molar ratio of 2:1 and is fired at 550 oC under one compensation disk. Solid-state lithium ion conductive powder of Li2SnOS-550-1S in the amount of 10, 20, 30, 40, and 50 wt.% was mixed with the modified PVDF-HFP electrolyte provided by the Institute of Nuclear Energy Research of Taiwan to form the inorganic/organic hybrid electrolytes. The hybrid electrolyte and its Li-ion battery device were evaluated for their properties. It was observed that the Li-ion conductivity of Li2SnOS-550/ PVDF-HFP hybrid films decreased with the increase in the amount of Li2SnOS-550, but the hybrid Li-ion battery with the sandwich structure of LiCoO2 /hybrid solid electrolyte/Li demonstrated improved performance. The hybrid Li-ion battery with the electrolyte of 30 wt.% Li2SnOS-550/ PVDF-HFP had the electrical capacity of 134.6 mAh/g and an efficiency of 95% for 30 cycle runs.
46
Chen, Yu-hsiu, and 陳育修. "Structural characterization and dynamic properties of organic-inorganic hybrid electrolytes based on alkoxysilane modification." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/34601708235558264454.
Abstract:
碩士國立中央大學
化學研究所
95
This research focus on the preparation and characterization of organic–inorganic hybrid electrolytes based on poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) (ED600、ED900、ED2000) complexed with LiClO4 via the co-condensation of tetraethoxysilane (TEOS) and 3-(triethoxysilyl)propyl isocyanate. The dry organic–inorganic hybrid electrolytes thus obtained were also plasticized by a solution of ethylene carbonate (EC)/propylene carbonate (PC) mixture (1:1 by volume). The ionic conductivity of the dry hybrid electrolyte films was enhanced by two orders of magnitude via plasticization, reaching a maximum conductivity value of 2.11×10-3 S/cm of the polymer molecule weight 2000 at 30℃. A variety of techniques such as DSC、TGA、FT-IR、SEM、XRD、AC Impedance and solid state NMR spectroscopy are performed to elucidate the realtionship between the structural and dynamic properties of the hybrid electrolyte and the ion mobility. According to DSC results, the glass transition temperature (Tg) raised with increasing the lithium salt content. By means of 2D 1H-13C WISE (WIdeline SEparation) NMR, the dynamic information within such a hybrid system can be qualitatively assessed by examining the proton line shapes in the F1 dimension that are directly related to structural elements resolved in the 13C CP/MAS NMR spectrum in the F2 dimension. Furthermore, the 7Li diffusion coefficients of the dry hybrid electrolytes were determined by pulsed gradient spin-echo (PGSE) experiment to correlate with the behavior of the ion conductivity.
47
Liang, Wuu-Jyh, and 梁武智. "Studies on Preparation and Characterization of Lithium-ion Polymer Electrolytes Based on Polysiloxane Hybrid." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/a6g24j.
Abstract:
博士國立成功大學
化學工程學系碩博士班
92
In this dissertation, two categories of novel materials for polymer electrolytes based on polysiloxane hybrid were prepared, and their microstructures associated with ion conduction behavior were investigated. This monograph is divided into four parts as follows: 1. A new hybrid polymer electrolyte system containing polysiloxane and polyether segments is designed and prepared via epoxide-crosslinking. The thermal behavior, structure, and ionic conductivity of the hybrid materials are investigated and characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), 13C solid-state NMR, and alternating current (AC) impedance measurements. Two glass transition temperatures have been observed, showing their dependence on the composition and LiClO4/PC content. The miscibility of the polymer components in the hybrid has been studied by examining the 1H spin-relaxation times in the laboratory frame (T1(H)) and in the rotating frame (T1r(H)) with various compositions. Multi-relaxation T1r(H) behavior has been observed, indicative of the presence of structural heterogeneity at the time scale of T1r(H). These results are correlated and used to interpret the phenomena of conductivity of lithium ion in the matrix of hybrid networks. 2. Solid polymer electrolytes based on epoxide-crosslinked polysiloxane/polyether hybrid (SE55) were characterized by DSC, impedance measurements and 7Li MAS NMR spectra. The DSC results indicate that initially a cation complexation dominated by the crosslink site of SE55 is present, and subsequently the formation of transient cross-links between Li+ ions and the ether oxygens of polyether segment results in an increase in Tg of the polyether segment (Tg1). However, the Tg1 remains almost invariant at the highest salt concentration of O/Li+ = 4. A VTF-like temperature dependence of ionic conductivity is observed, implying that the diffusion of charge carrier is coupled with the segmental motions of the polymer chains, and furthermore, a maximum conductivity value is observed at O/Li+ = 20 in the analyzed temperature range. Significantly, the 7Li MAS NMR spectra provide high spectral resolution to demonstrate the presence of at least two distinct Li+ local environments in SE55-based electrolytes. Detailed analyses of DSC and 7Li MAS NMR spectra results are achieved and discussed in terms of ion-polymer and ion-ion interactions, and further correlated with ion transport behavior. 3. Hybrid organic-inorganic materials derived from 3-glycidoxypropyltrimethoxyl- silane (GPTMS) were prepared via two different synthetic routes: (1) HCl-catalyzed sol-gel approach of silane followed by lithium perchlorate (LiClO4)/HCl catalyzed opening of epoxide; (2) simultaneous gelation of tin/LiClO4 catalyzed silane/epoxide groups. LiClO4 catalyzes the epoxide polymerization, and its effects on the structure of these hybrid materials were studied by solid-state 13C and 29Si CP/MAS NMR. The different synthetic routes have been found to significantly affect the polymerization behaviors of organic and inorganic sides in the presence of LiClO4. Larger amount of LiClO4 promotes the opening of epoxide and leads to the formation of longer PEO chains via HCl-catalyzed sol-gel approach, whereas in the case of tin-catalyzed, the faster polymerization of inorganic side hinders the growth of the organic network. The addition of LiClO4 was proved to be without crystalline salt present in the hybrid networks by wide-angle X-ray powder diffraction. 4. A new class of hybrid ionic conductors with covalent bonds between the organic poly(ethylene oxide) chains and the siloxane phase were prepared based on poly(ethylene glycol) diglycidyl ether (PEGDE) and 3-glycidoxypropyltrisilane (GPTMS) in the presence of lithium perchlorate (LiClO4) which acted as both ionic source and the epoxide ring-opening catalyst. The effect of salt-doped level on the microstructure and ionic conductivity of these composite electrolytes were investigated by means of Fourier transform infra-red (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), a. c. impedance and multinuclear solid-state nuclear magnetic resonance (NMR) measurements. Specially, DSC results indicate the formation of transient cross-links between Li+ ions and the ether oxygens on complexation with LiClO4 results in an increase in polyether segment Tg. However, the polyether segment Tg decreases at the highest salt concentration (5.0 mmol LiClO4 /g PEGDE). This is ascribed to the plasticizing effect, and can be further confirmed by 13C, 1H and 7Li MAS NMR spectra. Moreover, the behavior of ion transport is coupled with the segmental motions of polymer chains and also correlated with the interactions between ions and polymer host.
48
-zu, Hung, and 洪子迪. "Organic-Inorganic Hybrid Electrolytes Based on PPG-PEG-PPG Diamine, Alkoxysilanes, and Lithium Perchlorate." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/85032712347648602515.
Abstract:
碩士國立中央大學
化學研究所
95
A novel organic-inorganic hybrid electrolyte based on the formation of ureasils through the reaction in different ratios of poly (propylene glycol)-block-poly (ethylene glycol)-block-poly (propylene glycol) bis (2-aminopropyl ether) (ED2000) with 3-isocyanatopropyltriethoxysilane (ICPTES), followed by the via the co-condensation of 3-Glycidoxypropyl -trimethoxysilane (GLYMO) in the presence of LiClO4, has been prepared. The structure and functionality of the materials thus obtained were characterized a variety of techniques including alternating current impedance, FT-IR spectroscopy, differential scanning calorimetry, and multinuclear solid-state NMR spectroscopy. The results of DSC measurements indicate the formation of transient cross-links between Li+ ions and the ether oxygens on complexation with LiClO4, resulting in an increase in the soft segment Tg. Behavior of ionic conductivity is Vogel-Tammann-Fulcher (VTF)-type. Solid-state NMR was used to probe the structure and dynamics of organic and inorganic components in the hybrid electrolyte and 13C cross-polarization/magic angle spinning NMR results from variable contact time measurements indicated that a significant decrease in the mobility of the polymer chains as the salt content was increased. 7Li NMR characterization was performed to study ionic mobility by measuring spectral line widths, T1 relaxation times, and diffusion coefficients. The results of the lithium diffusion coefficient measurements indicated that the ionic conductivity in the present electrolytes was mainly dominated by the mobility of the lithium cations.
49
Wu, Chen Yang, and 吳震洋. "Study on Refillable Bi-electrolyte Fuel Cell and the Method of Range-extending Charging Hybrid Mechanism." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/xfhm2p.
Abstract:
博士國立臺北科技大學
機電科技研究所
104
Nowadays proton exchange membrane fuel cell has been prosperously developed all over the world. Nevertheless, there exist a lot of obstacles about how to store, transport and fill up with fuel cell, no matter in solid, liquid or gas state. For safety concern, electric car runs short-distance trips only, and such inconvenience makes it unable to be promoted successfully. Therefore, we design an innovatively structured fuel cell, which takes add-on solid/liquid two-state electrolyte fuel cell as auxiliary power, and uses a new mechanical range-extending charging and driving mechanism. The fuel cell makes use of a wheel motor attached with planetary gear assembly, making an electric car have its mileage, speed and torsion increased, and be charged when running. It is hoped that zinc air fuel cell can step out of the laboratory to facilitate practical use of electric cars. In the study we firstly use micro-spherical Zn grains to synthesize hollowed Zn microspheres. Then the microspheres are mixed with KOH electrolyte to formZn plaster, but resulting in aggregation and precipitation. Later on, we employ a stirring technique to make Zn grains become permanently suspended, thus solving the problems of aggregation and precipitation.We also use 65 wt. % KOHelectrolyte to fabricate 35 wt. % Zn colloids. We test the current density7.41 mA/cm2, specific energy by mass840.14 Wh/kg, and capacitance of cell3023 mAh. The Zn grains purchased for the study this time are mixed with KOH electrolyte to form Zn colloids. Using constant voltage method, and when open-circuit voltage being 1.4V, reaction area being 25cm2, relative humidity being 100% and temperature being 60oC, the constant voltage is 0.3V; its current density is 70 mA / cm2; and the power is 0.53W. Due to use of various additives, unexpected product must adhere to it, and full reaction complexity must be caused, so the effect is not as good as expected. And it cannot solve Zn grains’most headachy and toughest problems, i.e. aggregation and precipitation. But we solve the corrosion and inactivation problems of Zn grains by refillable bi-electrolyte fuel cell. Special designs like press grinding and anode flow channel can solve the commercial Zn powder’s aggregation and precipitation problems. New cathode flow channel, which avoids cathode from using large amount of PTFE in order to prevent outflow of electrolyte, is yet followed by the problem of insufficient air intake. The special design of cathode flow channel can solve the problem of small-amount leakage easily caused at the entrance of flow channel where cells are accumulated. The solid electrolyte of anion exchange membrane is taken as reaction membrane. We do not use the nonwoven-cloth-made separation membrane, which may cause anode penetration and result in an extremely great danger ofshort circuit of cell. Therefore, add-on feeding can solve the inconvenient conventional way, by which Zn plaster was manually applied all over the anode power collection grid, and allows fuel cell to step out of the laboratory. In the process of reaction, air bubbles and produced water are produced continuously, proving that the fuel cell designed by the study is successful.
50
Su, Jia-Hong, and 蘇佳鴻. "The Preparation of PPG/SiO2/IL/LiClO4 Hybrid Ionogel Electrolyte and Its Application on Lithium Battery." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/62462502915834739210.
Abstract:
碩士中原大學
奈米科技碩士學位學程
100
Most of the traditional preparation of polymer electrolytes are complicated and use organic solvent to dissolve the Polymer during the process. Besides, the solvent removing process usually causes energy loss and pollution problems, making the application of solid polymer electrolytes difficult to be pratical. In this study, the polymer/ionogel nanocomposite electrolyte membranes were successfully prepared by the one pot synthesis via sol-gel process with tetraethylorthosilicate (TEOS) as the precursor, 1-butyl-4-methyl imidazolium perchlorate [BMIM-ClO4], an ionic liquid, as ionic conductor, poly(propylene glycol) as reinforcer, lithium perchlorate (LiClO4) as Li-ion source and formic acid as catalyst. The as-prepared membranes were free-standing, translucent, flexible, non-crystallinity, solid-like electrolytes. Their physical and chemical properties were investigated by FT-IR, TGA, DSC, X-ray and SEM measurements. In addition, the capability and electrochemical properties were measured by performing charge-discharge cycles at different charge rate and temperature. The results showed that the one pot sol-gel process is a easier and cost effective method to prepare the polymer/ionogel nanocomposites without using organic solvents, avoiding the solvent removing problem.The highest conductivity of the polymer/ionogel nanocomposite electrolytes at room temperature was 5.88x10-4 S/cm exhibited by P5SI6C05. There is no weight loss until 237℃ from TGA study of P5SI6C05. The cyclic voltammetry measurement also showed that addition of the polymer enhanced the stability of electrochemical and interfaces properties of the nanocomposite elecatrolytes. Compared to the Ionic liquid electrolyte and ionogel electrolyte, the polymer/ionogel nanocomposite electrolyte showed better electrochemical properties and interface in the symmetric Li/ P5SI6C05/Li cells . The investigation of the effect of interactions among SiO2, BMIM,ClO4 and LiClO4 in the polymer/ionogel nanocomposite electrolyte showed that the activation energy of ionic migration in the nanocomposite electrolyte is lower than that in the ionic liquid electrolyte, revealing that the ion transport ability in the polymer/ionogel nanocomposite electrolyte is slightly better than that in the ionic liquid electrolyte. The capability of Li/P5SI6C05/LiFePO4 cell measured was unsatisfactory and is ascribed to the poor interface betweem the electrolyte membrane and the LiFePO4 electrode was that affected intercalation/outcalation ability of the Li+ to the cathode. Evan so, a commercial solar cell-LED was successfully assembled with the Li/P5SI6C05/LiFePO4 cell, and used the sun light to charge and discharge the cell. It is found that the cell is still functionable for more than 2 months, revealing the possiblility of application on the pocket eletronic products. As far as I understand, this is the first report of the half cell assembled by polymer/ionogel nanocomposite electrolyte with it’s lithium properties and applied to a pocket electronic device. The improvement of interface between the polymer/ionogels nanocomposite electrolyte and the electrodes of lithium battery is suggested for the future study.