Dissertationen zum Thema „Proton batteries“

Des batteries vertes qui sont sûres, fabriquées à partir de ressources facilement disponibles et éthiquement sourcées, rentables et faciles à fabriquer sont nécessaires. La technologie lithium-ion, qui utilise des matériaux à base de Li et des solvants inflammables toxiques, ne répond pas actuellement à tous ces critères. Dans cette optique, nous proposons une solution complémentaire aux batteries Li-ion sous la forme d'une batterie proton-ion aqueuse. Les principaux défis posés par les batteries aqueuses proviennent de leur faible densité énergétique, dû à la fenêtre de stabilité électrochimique restreinte de l'eau. Cette limitation réduit le champ des candidats capables d'intercaler des protons sans déclencher des réactions parasites telles que la réaction d'évolution de l'hydrogène (HER). Les matériaux TiO2 présentent une option intéressante pour être utilisés comme électrode négative pour l'insertion de protons. La structure chimique synthétisée en condition solvothermale a été modifiée pour obtenir trois composés distincts : un échantillon titanate de type lépidocrocite amorphe disposé en feuillet, qui a été optimisé par la suite avec des ions zinc chimiquement incorporé dans son interfeuillet, un anatase avec des défauts cationiques et un anatase stœchiométrique. L'analyse électrochimique des échantillons de titanate en feuillet optimisé au zinc et d'anatase défectueux, et leur intégration en tant qu'électrodes négatives dans des conditions de cellule complète, montre des caractéristiques prometteuses avec notamment, une fenêtre de potentiel étendue et une capacité réversible de protons accrue. Ces résultats ont été corrélés à la caractérisation des matériaux et à l'effet sur le transport des protons
Green batteries that are safe, made of readily available and ethically sourced resources, cost-effective and easy to manufacture are needed. Lithium-ion technology, which uses Li-based materials and toxic flammable solvents, does not currently meet all of these criteria. With this in mind, we propose a complementary solution to Li-ion batteries in the form of an aqueous proton-ion battery. The primary challenges posed by aqueous batteries stem from their low energy density, which is the result of the restricted electrochemical stability window of water. This limitation narrows the field of candidates capable of intercalating protons without triggering parasitic reactions such as the hydrogen evolution reaction (HER). TiO2 materials present an intriguing option for use as a negative electrode for proton insertion. The chemical structure synthesized in solvothermal condition has been modified to achieve three distinct compounds: a layered, amorphous lepidocrocite type titanate sample further optimized with zinc ions chemically incorporated into its interlayer, a cationic defective anatase, and a stoichiometric anatase. The electrochemical analysis of the zinc-optimized layered titanate and defective anatase samples, and their integration as negative electrodes in full-cell conditions, demonstrates promising characteristics with notably, an extended potential window and heightened reversible proton capacity. These results were correlated to the materials characterization and the effect on proton transport

The use of liquid electrolytes in energy storage devices are associated with several constraints pertaining to safety. Polymer electrolytes are suitable candidates to overcome several problems associated with free-flowing liquid electrolytes. The current thesis deals with the development of proton, lithium, and zinc conducting gel polymer electrolytes for electrochemical energy storage devices such as supercapacitors, lithium-metal batteries, and zinc-metal batteries. Special emphasis is given to the improvement of electrode|electrolyte interface in polymer electrolyte-based energy storage devices by the ultraviolet-light-induced in situ processing strategy. Ultimately, the prospects of employing polymer electrolytes as an alternative to liquid electrolytes in energy storage devices is revisited in this dissertation through four dedicated working chapters.
University Grants Commissions (UGC), India CSIR, India
AcSIR

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

The subject of this thesis relates to the design of new polymer electrolytes for battery and fuel cell applications. Classical Molecular Dynamics (MD) modelling studies are reported of the nano-structure and the local structure and dynamics for two types of polymer electrolyte host: poly(ethylene oxide) (PEO) for lithium batteries and perfluorosulfonic acid (PFSA) for polymer-based fuel cells. Both polymers have been modified by side-chain substitution, and the effect of this on charge-carrier transport has been investigated. The PEO system contains a 89-343 EO-unit backbone with 3-15 EO-unit side-chains, separated by 5-50 EO backbone units, for LiPF6 salt concentrations corresponding to Li:EO ratios of 1:10 and 1:30; the PFSA systems correspond to commercial Nafion®, Hyflon® (Dow®) and Aciplex® fuel-cell membranes, where the major differences again lie in the side-chain lengths. The PEO mobility is clearly enhanced by the introduction of side-chains, but is decreased on insertion of Li salts; mobilities differ by a factor of 2-3. At the higher Li concentration, many short side-chains (3-5 EO-units) give the highest ion mobility, while the mobility was greatest for side-chain lengths of 7-9 EO units at the lower concentration. A picture emerges of optimal Li+-ion mobility correlating with an optimal number of Li+ ions in the vicinity of mobile polymer segments, yet not involved in significant cross-linkages within the polymer host. Mobility in the PFSA-systems is promoted by higher water content. The influence of different side-chain lengths on local structure was minor, with Hyflon® displaying a somewhat lower degree of phase separation than Nafion®. Furthermore, the velocities of the water molecules and hydronium ions increase steadily from the polymer backbone/water interface towards the centre of the proton-conducting water channels. Because of its shorter side-chain length, the number of hydronium ions in the water channels is ~50% higher in Hyflon® than in Nafion® beyond the sulphonate end-groups; their hydronium-ion velocities are also ~10% higher. MD simulation has thus been shown to be a valuable tool to achieve better understanding of how to promote charge-carrier transport in polymer electrolyte hosts. Side-chains are shown to play a fundamental rôle in promoting local dynamics and influencing the nano-structure of these materials.

Un des freins à la commercialisation de masse de la pile à combustible et notamment de la technologie à membrane échangeuse de proton vient de sa faible durée de vie due à la difficulté de contrôler le système sous certaines conditions. Pour pallier à ce problème, l’élaboration d’un modèle mathématique précis de la pile à combustible à membrane échangeuse de protons permettant d’observer les variables internes et l'état de la pile à combustible au cours de son fonctionnement permettrait le développement de la stratégie de contrôle du système.Cette thèse propose d’élaborer un modèle dynamique multi-physique complet pour la pile à combustible à membrane échangeuse de protons. Le modèle proposé couvre les domaines multi-physiques pour les caractéristiques électriques, fluidiques et thermiques. Dans ces deux derniers domaines, les phénomènes transitoires sont notamment pris en compte dans le modèle proposé, tels que les comportements dynamiques de la teneur en eau de la membrane de la pile et la température. Par conséquent, ce modèle peut être utilisé pour analyser les effets de couplage des variables dynamiques entre différents domaines physiques.Grace à ce modèle ainsi définit, un second modèle multi-physique bidimensionnel plus détaillé est également présenté. Le modèle proposé couvre les domaines électriques et fluidiques avec une approche de modélisation 2-D innovante. Les distributions spatiales de quantité physique dans le domaine électrique peuvent ainsi être obtenues. Par conséquent, ce modèle 2-D PEMFC peut être utilisé pour étudier les influences des paramètres de modélisation sur la prédiction de performance multidimensionnelle locale. Une étude expérimentale est effectuée pour valider le modèle 2-D proposé avec une pile commerciale PEMFC Ballard NEXA de 1,2 kW.Dans un second chapitre, une analyse des phénomènes dynamiques est réalisée en fonction du modèle dynamique multidisciplinaire développé en s’appuyant sur la méthode RGA (gain relatif) pour diverses variables d'entrée de contrôle, afin d'analyser quantitativement les effets de couplage dans différents domaines physiques. L’étude s’intéresse entre autre aux interactions de la teneur en eau et de la température de la membrane. L'analyse de couplage présentée dans cette thèse peut aider les ingénieurs à concevoir et à optimiser les stratégies de contrôle des piles à combustible, en particulier pour la gestion de l'eau et de la chaleur dans les systèmes de piles à combustible.Une deuxième analyse portant sur la sensibilité aux paramètres de l'étude est effectuée sur la base du modèle multidisciplinaire bidimensionnel développé. Ces résultats d'analyse de sensibilité globale fournissent des informations utiles pour la compréhension de la dégradation, le réglage des paramètres et la simplification du modèle des piles à combustible.Dans un troisième temps, le modèle proposé se décline dans un algorithme de résolution mathématique en temps réel basé sur un algorithme de matrice tri diagonal efficace (TDMA). Les résultats expérimentaux démontrent les possibilités pratiques du modèle 2-D proposé pour le contrôle en temps réel avancé des systèmes de pile à combustible avec un temps de calcul de la boucle de contrôle de l'ordre de la milliseconde. Le temps d'exécution du modèle peut être quadruplé par rapport aux algorithme séquentiels présent dans la littérature; garantissant ainsi des décisions et des actions de contrôle rapide
Before mass commercialization of proton exchange membrane fuel cell, the research on the design of appropriate control strategies and auxiliaries need to be done for achieving proton exchange membrane fuel cell (PEMFC) optimal working modes. An accurate mathematical PEMFC model can be used to observe the internal variables and state of fuel cell during its operation, and could further greatly help the system control strategy development.A comprehensive multi-physical dynamic model for PEMFC is developed in chapter I. The proposed model covers multi-physical domains for electric, fluidic and thermal features. Particularly, the transient phenomena in both fluidic and thermal domain are simultaneously considered in the proposed model, such as the dynamic behaviors of fuel cell membrane water content and temperature. Therefore, this model can be used to analyze the coupling effects of dynamic variables among different physical domains.Based on the developed multi-physical PEMFC model, a full two-dimensional multi-physical model is further presented. The proposed model covers electrical and fluidic domains with an innovative 2-D modeling approach. In order to accurately describe the characteristics of reactant gas convection in the channels and diffusion through the gas diffusion layer, the gas pressure drop in the serpentine pipeline is comprehensively analyzed by fully taking the geometric form of flow field into consideration, such as the reactant gas pressure drop due to the pipeline sharp and U-bends. Based on the developed 2-D fluidic domain modeling results, spatial physical quantity distributions in electrical domain can be further obtained. Therefore, this 2-D PEMFC model can be use to study the influences of modeling parameters on the local multi-dimensional performance prediction. The simulation and experimental test are then performed to validate the proposed 2-D model with a commercial Ballard NEXA 1.2 kW PEMFC stack.In chapter II, analyses of dynamic phenomena step responses are conducted based on the developed multi-physical dynamic PEMFC model using the relative gain array (RGA) method for various control input variables, in order to quantitatively analyze the coupling effects in different physical domains, such as the interactions of membrane water content and temperature. Based on the calculated values of relative gain array, the proposed model can be considered as a fuel cell MIMO system, which could be divided into two independent control sub-systems by minimizing parameter coupling effects between each other. Due to the closely coupled parameters in the proposed first control sub-system, a decoupling control method is recommended to achieve optimized control results. The coupling analysis presented in this thesis can help engineers to design and optimize the fuel cell control strategies, especially for the water and thermal management in fuel cell systems

Cette thèse se concentre sur les méthodes d’apprentissage pour la transcription automatique de la batterie. Elles sont basées sur un algorithme de transcription utilisant une méthode de décomposition non-négative, la NMD. Cette thèse soulève deux principales problématiques : l’adaptation des méthodes au signal analysé et l’utilisation de l’apprentissage profond. La prise en compte des informations du signal analysé dans le modèle peut être réalisée par leur introduction durant les étapes de décomposition. Une première approche est de reformuler l’étape de décomposition dans un contexte probabiliste pour faciliter l’introduction d’informations a posteriori avec des méthodes comme la SI-PLCA et la NMD statistique. Une deuxième approche est d’implémenter directement dans la NMD une stratégie d’adaptation : l’application de filtres modelables aux motifs pour modéliser les conditions d’enregistrement ou l’adaptation des motifs appris directement au signal en appliquant de fortes contraintes pour conserver leur signification physique. La deuxième approche porte sur la sélection des segments de signaux à analyser. Il est préférable d’analyser les segments où au moins un événement percussif a lieu. Un détecteur d’onsets basé sur un réseau de neurones convolutif (CNN) est adapté pour détecter uniquement les onsets percussifs. Les résultats obtenus étant très intéressants, le détecteur est entraîné à ne détecter qu’un seul instrument permettant la réalisation de la transcription des trois principaux instruments de batterie avec trois CNN. Finalement, l’utilisation d’un CNN multi-sorties est étudiée pour transcrire la partie de batterie avec un seul réseau
This thesis focuses on learning methods for automatic transcription of the battery. They are based on a transcription algorithm using a non-negative decomposition method, NMD. This thesis raises two main issues: the adaptation of methods to the analyzed signal and the use of deep learning. Taking into account the information of the signal analyzed in the model can be achieved by their introduction during the decomposition steps. A first approach is to reformulate the decomposition step in a probabilistic context to facilitate the introduction of a posteriori information with methods such as SI-PLCA and statistical NMD. A second approach is to implement an adaptation strategy directly in the NMD: the application of modelable filters to the patterns to model the recording conditions or the adaptation of the learned patterns directly to the signal by applying strong constraints to preserve their physical meaning. The second approach concerns the selection of the signal segments to be analyzed. It is best to analyze segments where at least one percussive event occurs. An onset detector based on a convolutional neural network (CNN) is adapted to detect only percussive onsets. The results obtained being very interesting, the detector is trained to detect only one instrument allowing the transcription of the three main drum instruments with three CNNs. Finally, the use of a CNN multi-output is studied to transcribe the part of battery with a single network

Rechargeable lithium ion batteries (LIBs) are playing a dominant role in powering enormous numbers of portable electronic products and modernizing our everyday life. In the past decade, intense investment, research and development have been devoted to improving the major components of LIBs such as active materials, separators and electrolytes to further the application of LIBs for high energy consumption devices. The currently available LIBs however, cannot meet all requirements primarily because of low electronic/ion conductivity of electrodes. Furthermore, cost, safety, and environmental issues continue to impede further development of LIBs. In particular, the traditional electrode fabrication process commonly involves the consumption of toxic organic solvents such us NMP. To address all these issues, this thesis attempts to develop green electrode fabrication technologies for low cost and high performance LIBs by selection and modification of low cost and sustainable natural binders and removing the adoption of the toxic organic solvents. To convert the traditional LIB electrode production process from an organic solvent-based process into a green and water-based production technology, the water-soluble polymer Eastman AQTM 55S (EAQ) was chosen as a binder for graphite anodes in LIBs.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment.
Science, Environment, Engineering and Technology
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Des nanotubes de dioxyde de titane (TiO2nts) sont étudiés comme électrodes négatives potentielles pour des microbatteries Li-ion 3D. Ces TiO2nts lisses et hautement auto-organisés sont élaborés par anodisation du Ti dans des électrolytes organiques à base de glycérol ou d'éthylène glycol contenant des ions fluor et de l'eau en faible quantité. Les structures présentant un diamètre de 100 nm et une longueur variant de 1,5 à 14 µm sont particulièrement appropriés pour l'application visée. Les TiO2nts ont été tapissés de manière conforme par un électrolyte polymère (PMA-PEG) comportant un sel de lithium (LiTFSI) grâce à la technique d'électropolymérisation. Les études morphologiques menées par SEM et TEM ont montré que les nanotubes sont entièrement recouverts d'un film mince polymère de 10 nm d'épaisseur, ce qui permet de préserver la structure 3D de l'électrode. Les tests électrochimiques portant sur les nanotubes seuls ainsi que sur les TiO2nts tapissés d'électrolyte polymère ont été effectués en demi-cellule et en cellule complète en utilisant un électrolyte polymère à base de MA-PEG contenant du LiTFSI. En demi-cellule, les TiO2nts de 1,5 µm de long delivrent une capacité surfacique de 22 µAh cm-2 relativement stable sur 100 cycles. La performance de la demi-cellule est améliorée de 45% à une cinétique de 1C lorsque les TiO2nts sont tapissés de manière conforme par un electrolyte polymère (PMA-PEG). Cet effet résulte d'un meilleur transport de charges lié à l'augmentation de la surface de contact entre l'électrode et l'électrolyte
Titania nanotubes (TiO2nts) as potential negative electrode for 3D lithium-ion microbatteries have been reported. Smooth and highly-organized TiO2nts are fabricated by electrochemical anodization of Ti foil in glycerol or ethylene glycol electrolyte containing fluoride ions and small amount of water. As-formed TiO2nts shows the open tube diameter of 100 nm and the length from 1.5 to 14 µm which are suitable for the fabrication of the 3D microcbatteries. The deposition of PMA-PEG polymer electrolyte carrying LiTFSI salt into TiO2nts has been achieved by the electropolymerization reaction. The morphology studies by SEM and TEM reveal that the nanotubes are conformally coated with 10 nm of the polymer layer at the inner and outer walls from the bottom to the top without closing the tube opening. 1H NMR and SEC show that the electropolymerization leads to PMA-PEG that mainly consists of trimers. XPS confirms the presence of LiTFSI salt in the oligomers.The electrochemical studies of the as-formed TiO2nts and polymer-coated TiO2nts have been performed in the half-cells and full cells using MA-PEG gel electrolyte containing LiTFSI in Whatman paper as separator. The half-cell of TiO2nts (1.5 µm long) delivers a stable capacity of 22 µAh cm-2 over 100 cycles. The performance of the half-cell is improved by 45% at 1C when TiO2nts are conformally coated with the polymer electrolyte. The better performance results from the increased contact area between electrode and electrolyte, thereby improving the charge transport

Redox flow batteries (RFBs) are electrochemical cells that are able to reversibly convert the chemical energy stored into the redox couples into electrical power. Vanadium redox flow batteries (VRFBs) exploit redox couples both based on vanadium species. To make VRFB technology commercially viable, technical and economic barriers including high capital cost and rapid capacity decay need to be addressed. The primary objective of this thesis is to achieve high performance VRFB with long durability, mainly by reducing the vanadium permeability through the membrane. Nowadays perfluorosulfonic acid membranes are widely used in VRFB, such as Nafion. Nafion has high chemical and mechanical stability, and it exhibits good proton conductivity. Nevertheless, the VRFB cell with Nafion membrane has fast capacity decay due to the high vanadium crossover. In an effort to overcome the limitations of Nafion, this thesis reports the synthesis and characterization of hybrid inorganic-organic proton-conducting membrane alternatives to classic perfluorinated ionomers. Two families of hybrid membranes were synthesized: 1) Nafion membrane doped with WO3 nanofiller, in order to reduce its vanadium crossover while maintaining the high proton conductivity; 2) synthesis of sulfonated poly (ether ether ketone) (SPEEK) membrane with optimized degree of sulfonation as an alternative low-cost membrane. Then further dope the SPEEK membrane with WO3 to reduce vanadium crossover. For all the hybrid membranes prepared by a solvent-casting procedure, the introduction of WO3 nanoparticles does not alter significantly the thermal degradation events of the polymer host and the hybrid membranes maintain the good thermal stability. MDSC reveals that in hybrid membranes the endothermic events are slightly shifted attributed to the formation of “dynamic crosslinks” between the WO3 nanoparticles and the polymer host, that stabilize the hybrid membrane. The hydrophilic domains of the polymer host are reduced in size as the content of WO3 is raised. The water uptake of hybrid membranes decreases with the increasing loading of WO3 nanofillers; as a consequence, the pathways of charge migration become more tortuous. While the higher charge migration tortuosity would correspond to a dramatically lower permeability to vanadium species. The tortuosity for protons is likely much less than that for vanadium, as the vanadium ions are only passing through the bulk water, while the protons are also delocalized at the polymer-nanofiller interfaces in the presence of interface water. The vanadium permeability of hybrid membranes decreases significantly and the ion selectivity is much improved in comparison with Nafion. The hybrid membranes with highest ion selectivity are chosen for VRFB single cell test. They exhibits a higher coulombic efficiency in comparison with the Nafion 212 reference. The reduced permeation of vanadium species is also revealed by the lower discharge capacity decay and longer self-discharge times for the hybrid membranes. Therefore, the new family of hybrid membranes may be promising candidates for application in VRFBs. The final chapter describes the study by Raman spectroscopy of the species present in the positive feed of a VRFB as a function of the state of charge (SOC). Changes in complexation due to presence of stable oxygenated coordination complexes of vanadium, also interacting strongly with HSO4- and SO42- ligands, are put in evidence. In particular, it is demonstrated that the positive feed includes additional species beyond VO2+ and VO2+, with a particular reference to dimers such as HV2O5- and H3V2O7-. Such species may be accounted to understand in detail the charge-discharge processes taking place at the electrodes of a VRFB. Indeed, on these bases, the processes are expected to involve a broad distribution of V(IV) and V(V) species, that may end up affecting significantly crucial macroscopic features of the overall VRFB.
Le batterie Redox a Flusso (RFB) sono celle elettrochimiche capaci di convertire reversibilmente l'energia chimica immagazzinata in coppie redox in energia elettrica. Le batterie a flusso al vanadio (VRFB) sfruttano coppie redox entrambe basate su specie di vanadio. Per far sì che la tecnologia VRFB sia commercialmente valida, occorre superare barriere tecniche ed economiche che includono elevati costi di capitale ed un rapido decadimento della capacità. L'obiettivo principale di questa tesi è di ottenere VRFB ad alte prestazioni e di lunga durata, principalmente riducendo la permeabilità del vanadio attraverso la membrana. Al giorno d'oggi nelle VRFB vengono utilizzate membrane a base di acido perfluorosolfonico, come il Nafion. Il Nafion ha un'elevata stabilità chimica e meccanica, e presenta una buona conducibilità protonica. La VRFB con membrana al Nafion hanno un rapido decadimento della capacità a causa dell'alto crossover del vanadio. Per superare i limiti del Nafion, questa tesi riporta la sintesi e la caratterizzazione di membrane ibride inorganico-organiche conduttrici di protoni alternative agli ionomeri perfluorurati. Due famiglie di membrane ibride sono state ottenute: 1) membrana di Nafion drogata con nanofiller WO3, per ridurre il crossover del vanadio mantenendo un’elevata conducibilità protonica; 2) sintesi di una membrana a base di poli(etere-etere-chetone) solfonato (SPEEK), con grado di solfonazione ottimizzato. Anche la membrana a base di SPEEK viene poi drogata con WO3 per ridurre il crossover del vanadio. Nelle membrane ibride preparate mediante una procedura di solvent-casting, l'introduzione di nanoparticelle di WO3 non altera in modo significativo gli eventi di degradazione termica della matrice polimerica, mantenendo così una buona stabilità termica. Misure MDSC rivelano che nelle membrane ibride gli eventi termici sono leggermente spostati a causa della formazione di "crosslink dinamici" tra le nanoparticelle di WO3 e la matrice polimerica, che stabilizzano la membrana. La dimensione dei domini idrofili e l’assorbimento d’acqua della mambrana si riducono all’aumentare del contenuto di WO3. Di conseguenza, i percorsi di migrazione di carica diventano più tortuosi. Questa maggiore tortuosità alla migrazione di carica corrisponde ad una permeabilità inferiore delle specie vanadio. Al contrario del vanadio, la tortuosità ha probabilmente un effetto inferiore per i protoni, poiché gli ioni di vanadio attraversano solo i domini massivi di acqua, mentre i protoni vengono scambiati anche alle interfacce polimero-nanofiller. Così, la permeabilità al vanadio delle membrane ibride diminuisce significativamente e la selettività degli ioni è molto migliorata rispetto al Nafion. Le migliori membrane ibride sono scelte per il test in cella VRFB. Esse esibiscono una maggiore efficienza coulombica rispetto al riferimento Nafion 212. La ridotta permeazione delle specie di vanadio è rivelata anche dal minore decadimento della capacità di scarica e dai tempi di autoscarica più lunghi per le membrane ibride. Pertanto, la nuova famiglia di membrane ibride è un promettente candidato per l'applicazione in VRFB. Il capitolo finale descrive lo studio, attraverso la spettroscopia Raman, delle specie presenti nella soluzione positiva (catolita) di una VRFB in funzione dello stato di carica (SOC). Gli equilibri dovuti alla presenza di complessi di coordinazione del vanadio, che interagiscono fortemente con i leganti HSO4- e SO42-, vengono evidenziati. In particolare, viene dimostrato come il catolita includa specie addizionali oltre a VO2+ e VO2+, quali HV2O5- e H3V2O7-. La presenza di tali specie deve essere considerata per comprendere in dettaglio i processi di scarica e carica che avvengono agli elettrodi di una VRFB. Infatti, su queste basi, ci si aspetta il coinvolgimento di un'ampia distribuzione di specie V(IV) e V(V), che potrebbero influenzare le caratteristiche macroscopiche significativamente cruciali di una VRFB.

Les trois grands domaines d'application de batteries au plomb sont les batteries de démarrage, les batteries de traction et les batteries stationnaires. Les évolutions des marchés, notamment celui de l'énergie, ouvrent de nouvelles applications de stockage par accumulateur au plomb: transports électriques, énergies renouvelables dont éolien et photovoltaïque, stockage réseau, qualité, secours. Dans la plupart des cas, les contraintes de l'application mènent à revoir profondément les algorithmes de charge. Nous avons mené différentes études sur les batteries au plomb dans des conditions extrêmes: charge rapide pour batteries ouvertes, maintien en charge pour batteries stationnaires, décharge profonde avec inversion de polarité. À partir de ces travaux, un nouvel algorithme de charge rapide avec une phase de déstratification précoce a été mis au point. De plus, une nouvelle méthode de maintien en charge par faible courant imposé a été testée sur différentes technologies de batteries au plomb. Elle montre plusieurs avantages en termes de réduction importante de la corrosion, de diminution de la perte d'eau due à la corrosion et de besoin de charges périodiques.

Les syndromes myélodysplasiques (SMD) sont un groupe hétérogène de maladies clonales de la cellule souche hématopoïétique caractérisé par une dysplasie de la lignée myéloïde. Ces syndromes évoluent dans environ 40% des cas en leucémie aiguë myéloïde (LAM). L'étude des modèles animaux représente une opportunité de mieux comprendre la leucémogénèse myéloïde. C'est aussi le point de départ du développement de nouvelles thérapies afin de mieux traiter les patients atteints d'un SMD et d'une LAM post SMD. Nous avons réalisé un criblage génomique à grande échelle par puce à ADN afin d'obtenir le profil d'expression génique de deux modèles transgéniques de SMD et LAM post SMD. Ces profils ont été comparés avec le profil d'expression génique de patients afin de mettre en évidence leur pertinence pour l'étude des SMD et LAM post SMD de l'homme. Cette analyse a montré des similarités entre les profils d'expression des modèles et des patients et mis en avant des altérations de l'expression de gènes impliqués dans des fonctions cellulaires encore peu décrites comme impliquées dans le développement de la maladie. Nous avons également évalué l'efficacité d'un vaccin à ADN non spécifique, le pVAX14, et d'une molécule inhibitrice des protéines à domaine BH3 dont les protéines anti-apoptotiques de la famille BCL-2, l'ABT-737, dans différents modèles animaux. Dans un modèle murin transplantable de LAP et le modèle murin transgénique de SMD de haut risque, la vaccination par pVAX14 entraîne une prolongation de la survie ainsi qu'une activation de la réponse immunitaire humorale et cellulaire similaire à ce qui a déjà été observé dans le modèle murin LAP avec un vaccin spécifique exprimant un antigène du gènes de fusion PML-RARot. Ces résultats suggèrent une utilisation « générique » du pVAX14 dans d'autres types de cancers ou hémopathies malignes. L'ABT-737 quand à lui, améliore la survie dans le modèle murin transgénique de SMD de haut risque en ciblant les cellules initiatrices de la leucémie et les cellules progénitrices primitives, en régulant le cycle cellulaire, la différenciation et l'apoptose
Myelodysplastic syndromes (MDS) are a heterogeneous group of clonai hematopoietic stem tell diseases characterized by dysplasia in the myeloid lineage. 40% of MDS patients evolve to an acute myeloid leukemia (AML). The study of animal models provides an opportunity to better understand the myeloid leukemogenesis. It is also the starting point for the development of nevi therapies to better treat patients with MDS and AML post a SMD. We conducted a large-scale genomic screening by DNA chip to obtain the gene expression profile of two transgenic mouse models of MDS and AML post MDS. These profiles were compared with the gene expression profile of patients in order to highlight their relevance to the study of MDS and AML post SMD. These analyses showed similarities between expression profiles of patient and mouse models and have shown alterations in expression of genes involved in cellular functions described as yet little involved in the development of the disease. We also assessed the efficacy of a DNA nonspecific vaccine, the pVAX14, and a molecule which inhibite proteins BH3 domain. ABT-737 has an effect on anti-apoptotic BCL-2 proteins family. In a mouse model of transplantable LAP and transgenic mouse model of high-risk MDS, vaccinatior with pVAX14 increase mice survival and activate the immune response as it was already shown in the LAP mouse model with a specific vaccine expressing PML-RAR alpha antigen. These results suggest a use "generic" pVAX14 to treat other types of cancer or haematological malignancies. ABT-737 improves the survival in the transgenic mouse model of high-risk MDS and target leukemia initiating cells and primitive progenitor cells, by regulating the tell cycle, differentiation, and apoptosis

Améliorer notre compréhension des mécanismes de transport/transfert de charges et de stockage de charges dans les films d'oxyde métallique semi-conducteur mésoporeux transparents (fonctionnalisés ou non par des chromophores redox-actifs) dans des électrolytes aqueux est d'une importance fondamentale pour le développement et l'optimisation d'une large gamme de dispositifs de production ou de stockage d'énergie éco-compatibles et/ou éco-durables (cellules solaires à colorants, batteries, photoélectrolyseurs, ….). Dans ce but, des films de TiO2 semi-conducteur mésoporeux préparés par dépôt sous incidence rasante (GLAD-TiO2) ont été sélectionnés pour leur grande surface spécifique, leur morphologie bien contrôlée, leur transparence élevée dans le visible et leur semiconductivité bien définie qui peut être facilement ajustée par l’application d’un potentiel externe, autorisant ainsi leur caractérisation aisée par spectroélectrochimie en temps réel. Nous avons d'abord étudié le transfert et transport de charges dans des électrodes GLAD-ITO et GLAD-TiO2 fonctionnalisées par une porphyrine de manganèse redox-active jouant à la fois le rôle de chromophore et de catalyseur. Nous avons démontré que la réponse électrochimique des électrodes ainsi modifiées, enregistrée en l'absence ou en présence du substrat O2, dépend fortement de la conductivité du film mésoporeux. En utilisant la voltamétrie cyclique couplée à la spectroscopie d'absorption UV-visible, nous avons pu extraire des informations clés telles que la vitesse du transfert d'électrons hétérogène entre le chromophore redox immobilisé et le matériau semi-conducteur, et aussi pu rationaliser le comportement électrochimique spécifique obtenu sur un film GLAD-TiO2 modifié par la porphyrine en condition catalytique. En parallèle, nous avons développé un procédé de fonctionnalisation de ces films d'oxyde métallique mésoporeux (en l’occurrence des films GLAD-ITO) par électrogreffage de sels d'aryldiazonium générés in situ, permettant d'obtenir des électrodes fonctionnalisées avec un taux de recouvrement surfacique élevé et une stabilité dans le temps particulièrement bonne en conditions hydrolytiques. Nous avons également étudié le stockage de charges au sein d’électrodes GLAD-TiO2 dans divers électrolytes aqueux. Nous avons notamment démontré pour la première fois qu’une insertion rapide, massive et réversible de protons peut être effectuée dans des films de TiO2 nanostructurés amorphes immergés dans un tampon aqueux neutre, le donneur de protons étant alors la forme acide faible du tampon. Nous avons également démontré que ce processus de stockage d’électrons couplé à l’insertion de protons peut se produire sur toute la gamme de pH et pour un vaste panel d'acides faibles organiques ou inorganiques, mais aussi de complexes aqueux d'ions métalliques multivalents, à condition que le potentiel appliqué et le pKa de l'acide faible soient correctement ajustés
Better understanding of the mechanisms of charge transport/transfer and charge storage in transparent mesoporous semiconductive metal oxide films (either functionalized or not by redox-active chromophores) in aqueous electrolytes is of fundamental importance for the development and optimization of a wide range of safe, eco-compatible and sustainable energy producing or energy storage devices (e.g., dye-sensitized solar cells, batteries, photoelectrocatalytic cells, …). To address this question, mesoporous semiconductive TiO2 films prepared by glancing angle deposition (GLAD-TiO2) were selected for their unique high surface area, well-controlled morphology, high transparency in the visible, and well-defined semiconductivity that can be easily adjusted through an external bias, allowing thus their characterization by real-time spectroelectrochemistry. We first investigated charge transfer/transport at GLAD-ITO and GLAD-TiO2 electrodes functionalized by a redox-active manganese porphyrin that can play both the role of chromophore and catalyst. We demonstrate that the electrochemical response of the modified electrodes, recorded either in the absence or presence of O2 as substrate, is strongly dependent on the mesoporous film conductivity. By using cyclic voltammetry coupled to UV-visible absorption spectroscopy, we were able to recover some key information such as the heterogeneous electron transfer rate between the immobilized redox-active dye and the semiconductive material, and also to rationalize the specific electrochemical behavior obtained at a porphyrin-modified GLAD TiO2 film under catalytic turnover. In parallel, we developed a new functionalization procedure of mesoporous metal oxide films (GLAD-ITO in the present case) by electrografting of in-situ generated aryldiazonium salts, allowing for modified electrodes characterized by both a high surface coverage and a particularly good stability over time under hydrolytic conditions. Also, we investigated charge storage at GLAD-TiO2 electrodes under various aqueous electrolytic conditions. We notably evidenced for the first time that fast, massive, and reversible insertion of protons can occur in amorphous nanostructured TiO2 films immersed in near neutral aqueous buffer, with the proton donor being the weak acid form of the buffer but not water. We also demonstrated that this proton-coupled electron charge storage process can occur over the entire range of pH and for a wide range of organic or inorganic weak acids, but also of multivalent metal ion aquo complexes, as long as the applied potential and pKa of weak acid are properly adjusted

L'estimation de l'état de charge (SOC) est un point crucial pour la sécurité des performances et la durée de vie des batteries lithium-ion (Li-ion) utilisées pour alimenter les VE.Dans cette thèse, la précision de l'estimation de l'état de charge est étudiée à l'aide d'algorithmes de réseaux neuronaux récurrents profonds (DRNN). Pour ce faire, pour une cellule d’une batterie Li-ion, trois nouvelles méthodes sont proposées : une mémoire bidirectionnelle à long et court terme (BiLSTM), une mémoire robuste à long et court terme (RoLSTM) et une technique d'unités récurrentes à grille (GRU).En utilisant ces techniques, on ne dépend pas de modèles précis de la batterie et on peut éviter les méthodes mathématiques complexes, en particulier dans un bloc de batterie. En outre, ces modèles sont capables d'estimer précisément le SOC à des températures variables. En outre, contrairement au réseau de neurones récursif traditionnel dont le contenu est réécrit à chaque fois, ces réseaux peuvent décider de préserver la mémoire actuelle grâce aux passerelles proposées. Dans ce cas, il peut facilement transférer l'information sur de longs chemins pour recevoir et maintenir des dépendances à long terme.La comparaison des résultats indique que le réseau BiLSTM a de meilleures performances que les deux autres méthodes. De plus, le modèle BiLSTM peut travailler avec des séquences plus longues provenant de deux directions, le passé et le futur, sans problème de disparition du gradient. Cette caractéristique permet de sélectionner une longueur de séquence équivalente à une période de décharge dans un cycle de conduite, et d'obtenir une plus grande précision dans l'estimation. En outre, ce modèle s'est bien comporté face à une valeur initiale incorrecte du SOC.Enfin, une nouvelle méthode BiLSTM a été introduite pour estimer le SOC d'un pack de batteries dans un EV. Le logiciel IPG Carmaker a été utilisé pour collecter les données et tester le modèle en simulation. Les résultats ont montré que l'algorithme proposé peut fournir une bonne estimation du SOC sans utilisation de filtre dans le système de gestion de la batterie (BMS)
The State Of Charge (SOC) estimation is a significant issue for safe performance and the lifespan of Lithium-ion (Li-ion) batteries, which is used to power the Electric Vehicles (EVs). In this thesis, the accuracy of SOC estimation is investigated using Deep Recurrent Neural Network (DRNN) algorithms. To do this, for a one cell Li-ion battery, three new SOC estimator based on different DRNN algorithms are proposed: a Bidirectional LSTM (BiLSTM) method, Robust Long-Short Term Memory (RoLSTM) algorithm, and a Gated Recurrent Units (GRUs) technique. Using these, one is not dependent on precise battery models and can avoid complicated mathematical methods especially in a battery pack. In addition, these models are able to precisely estimate the SOC at varying temperature. Also, unlike the traditional recursive neural network where content is re-written at each time, these networks can decide on preserving the current memory through the proposed gateways. In such case, it can easily transfer the information over long paths to receive and maintain long-term dependencies. Comparing the results indicates the BiLSTM network has a better performance than the other two. Moreover, the BiLSTM model can work with longer sequences from two direction, the past and the future, without gradient vanishing problem. This feature helps to select a sequence length as much as a discharge period in one drive cycle, and to have more accuracy in the estimation. Also, this model well behaved against the incorrect initial value of SOC. Finally, a new BiLSTM method introduced to estimate the SOC of a pack of batteries in an Ev. IPG Carmaker software was used to collect data and test the model in the simulation. The results showed that the suggested algorithm can provide a good SOC estimation without using any filter in the Battery Management System (BMS)

Les leucémies aiguës lymphoblastiques de la lignée T (LAL-T) sont des proliférations malignes présentant les caractéristiques de précurseurs lymphoïdes thymiques bloqués dans leur différenciation. La mise en évidence et la caractérisation des remaniements/mutations somatiques du génome, permettant d'identifier des gènes dérégulés, constitue une étape majeure pour progresser dans la compréhension des mécanismes de leucémogenèse et l'identification des voies biologiques critiques des cellules tumorales. Nous avons entrepris un crible des remaniements génomiques à partir d'une grande série de cas de LAL-T annotés pour l'immunophénotype et l'expression des principaux oncogènes (TAL1, TLX1, TLX3, LMO2. . . ). Deux approches génétiques pan-génomes ont été utilisées : i) un criblage par FISH des translocations associées aux gènes du TCR puis l'identification des régions partenaires par clonage par PCR cerclée, ii) un profilage chromosomique par CGH-array à la recherche de délétîons ou duplications cryptiques. Nous avons ainsi identifié plusieurs nouveaux remaniements récurrents des LAL-T et montré qu'ils dérégulaient l'expression de gènes importants pour la différenciation thymique : les gènes HOXA, Cycline D2 et C-MYB. Ces anomalies ont été intégrées dans un vaste portrait moléculaire des LAL-T établi par une analyse de données d'expression à large échelle. De nouveaux sous-types oncogéniques ont été définis, notamment un groupe HOXA incluant les cas avec translocations TCRB-HOXA ou microdélétion SET-NUP214, et un sous-type homogène de leucémies T du très jeune enfant associé à la translocation TCRB-MYB
T-cell acute lymphoblastic leukemia are malignancies derived from lymphoid thymic precursors arrested in their differentiation. Identification and characterization of somatic rearrangements/mutations of the genome is a major step for leukemogenesïs mechanisms understanding and identification of the critical biological pathways of tumoral cells. We performed a screen for genomic rearrangements in a series of adult and pediatric T-ALL cases annotated for immunophenotypic data and expression of known oncogenes (TAL1, TLX1, TLX3, LMO2. . . ). Two genome-wide approaches were used: i) FISH screening for TCR-mediated translocations and breakpoint doning using cirded-PCR to identify partner sequences, ii) genomic profiling using array-CGH in a search for cryptic deletions or duplications. We thus identified several new recurrent rearrangements of T-ALL and showed that they lead to dysregulated expression of genes critical for thymic differentation: HOXA, Cylin D2 and C-MYB gènes. These abnormalities were included in a general molecular portrait of T-ALL performed by lange-scale gene expression analysis. Importantly, new oncogenic subtypes were defined, including a HOXA-group including cases with TCRB-HOXA translocation and SET-NUP214 microdeletion, and a homogeneous subtype of T-cell leukemias in very young children with TCRB-MYB translocation

abstract: Microgrids are a subset of the modern power structure; using distributed generation (DG) to supply power to communities rather than vast regions. The reduced scale mitigates loss allowing the power produced to do more with better control, giving greater security, reliability, and design flexibility. This paper explores the performance and cost viability of a hybrid grid-tied microgrid that utilizes Photovoltaic (PV), batteries, and fuel cell (FC) technology. The concept proposes that each community home is equipped with more PV than is required for normal operation. As the homes are part of a microgrid, excess or unused energy from one home is collected for use elsewhere within the microgrid footprint. The surplus power that would have been discarded becomes a community asset, and is used to run intermittent services. In this paper, the modeled community does not have parking adjacent to each home allowing for the installment of a privately owned slower Level 2 charger, making EV ownership option untenable. A solution is to provide a Level 3 DC Quick Charger (DCQC) as the intermittent service. The addition of batteries and Fuel Cells are meant to increase load leveling, reliability, and instill limited island capability.
Dissertation/Thesis
M.S.Tech Engineering 2013

The research presented in this thesis focuses on developing new functional polymeric materials that can conduct ions, H+, or OH - or Li+. The motivation behind this work was to understand the similarities and/or differences in the structure property relationships between polymer membranes and the conductivity of H+ and OH - ions, and between polymer membranes and the anhydrous conductivity of H+ and Li+ ions. This understanding is critical to developing durable polymer membranes with high H+, OH - and Li+ ion conductivity for proton exchange membrane fuel cells (PEMFCs), alkaline anion exchange membrane fuel cells (AAEMFCs) and lithium ion batteries respectively. Chapter 1 describes the basic functioning of PEMFCs, AAEMFCs and lithium ion batteries, the challenges associated with each research topic, and the fundamental mechanisms of ion transport. The proton conducting properties of poly(4-vinyl-1H-1,2,3-triazole) were investigated on a macroscopic scale by impedance spectroscopy and microscopic scale by solid state MAS NMR. It was found that proton conductivity is independent of molecular weight of the polymer, but influenced by orders of magnitude by the presence of residual dimethylformamide. To improve the mechanical properties of otherwise liquid-like 1H-1,2,3-triazole functionalized polysiloxane homopolymers, hybrid inorganic-organic proton exchange membranes (PEMs) containing 1H-1,2,3-triazole grafted alkoxy silanes were synthesized, using sol-gel chemistry. This method enabled self-supporting membranes having proton conductivity comparable to uncrosslinked homopolymers. One of the biggest challenges with AEMs for use in AAEMFCs is finding a cationic polyelectrolyte that is chemically stable at elevated temperatures in high pH environment. Novel triazolium ionic salts were developed, having greater chemical stability under alkaline conditions compared to existing imidazolium ionic salts. However, the chemical stability of triazolium cations was not sufficient for AAEMFC applications. Excellent chemical stability of (C5H5)2Co+ in 2 M NaOH at 80°C over 30 days was demonstrated and polymerizable vinyl functionalized cobaltocenium monomers were synthesized. This work paves the way for future development of AEMs containing cobaltocenium moieties to facilitate hydroxide ion transport. Polymers containing covalently attached cyclic carbonates were synthesized and doped with lithium triflate and their lithium ion conductivities were investigated. The findings highlight the importance of high charge carrier density and flexibility of the polymer matrix to achieve high lithium ion conductivity. These results are similar to the key factors influencing anhydrous proton transport.

Tese no âmbito do Doutoramento em Química, ramo de especialização em Fotoquímica, apresentada ao Departamento de Química da Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
Indigo, an iconic molecule of colour, is included in the most ancient and important natural dyes used by mankind. The longevity as a colourant and unique properties of this compound are related with its high (photo)stability which is linked to a rapid proton transfer in the excited state (ESPT). In the past few years, indigo and its derivatives have gained renewed interest due to applications in several fields such as photoswitches, electronic devices and sensors. The study and development of an improved and fast approach for the synthesis of mono- and di-substituted indigo derivatives combined with a comprehensive characterization of their electronic spectral and photophysical properties in different solvents and temperatures was undertaken and constitutes the first part of this thesis. The study was further rationalized with density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations. The second part of this thesis reports the synthesis of tryptanthrin and tryptanthrin derivatives, important compounds with a variety of biological and pharmacological applications as well as redox properties. Tryptanthrin was synthesized from indigo under mild conditions using microwave irradiation. A comprehensive study of the excited state of these compounds was also undertaken. In contrast with indigo, emission of the triplet state of tryptanthrin and its derivatives, with the exception of 2-aminotryptanthrin, where fluorescence dominates, was observed with a very efficient singlet oxygen sensitization quantum yield. These results indicate intersystem crossing (ISC) to be the dominant deactivation channel in tryptanthrin and its derivatives, with high quantum yields. Time-resolved fluorescence and femtosecond transient absorption (fs-TA) data, further supported with TDDFT calculations, show for tryptanthrin, two species, a locally excited (LE) and a charge transfer (CT) with a highly reversible inter-conversion rate constant (LE to CT state). A pratical and modern application of storage of chemical energy with, an aqueous organometallic and an all-organic redox flow battery (RFB) with sulfonated tryptanthrin, working at neutral pH and with long-term stability, was further developed. The single cell tests showed reproducible charge-discharge cycles with significant improvement results for the aqueous all-organic RFB, with higth coulombic, voltaic and energetic efficiencies stabilized over several working cycles. The work paves the way to the promising development of new tryptanthrin based structures for environmentally friendly aqueous all-organic RFBs working at neutral pH values.
O índigo, uma icónica molécula da cor, é um dos corantes mais antigos e importantes usados pela humanidade. A longevidade deste corante assim como as suas propriedades únicas estão relacionadas com a sua elevada (foto)estabilidade que esta ligada a uma rápida transferência de protão no estado excitado. Nos últimos anos, o índigo e os seus derivados ganharam um interesse renovado devido a aplicações em diversos campos, tais como, interruptores fotónicos, dispositivos elétricos e sensores. O estudo e desenvolvimento de uma abordagem mais rápida e aprimorada da síntese de derivados mono- e di-substituídos do índigo combinados com uma caracterização abrangente das suas propriedades eletrónicas, espectrais e fotofísicas, em diferentes solventes e temperaturas foi realizada e constitui a primeira parte desta tese. O estudo foi racionalizado com cálculos teóricos através da teoria do funcional da densidade (DFT) e da teoria do funcional da densidade dependente do tempo (TDDFT). A segunda parte desta tese relata a síntese da triptantrina e seus derivados. Estes compostos são importantes pois para além de apresentarem uma vasta aplicação biológica e farmacológica possuem também propriedades de oxidação-redução. A triptantrina foi sintetizada a partir do índigo sob condições suaves utilizando radiação de micro-ondas como fonte de energia. Um estudo abrangente do estado excitado destes compostos foi também realizado. Em contraste com o índigo, na triptantrina e seus derivados, com exceção da 2-aminotriptantrina, onde a fluorescência domina, foi observada emissão do estado tripleto com rendimentos quânticos de formação de oxigénio singleto muito eficientes. Estes resultados indicam que a conversão intersistemas (ISC) é a principal via de desativação na triptantrina e seus derivados, com elevados rendimentos quântico. Os dados de fluorescência resolvida no tempo e absorção transiente de femtosegundos (fs-TA), complementados com cálculos TDDFT, mostram que no caso da triptantrina, existem duas espécies, uma excitada localmente (LE) e uma com transferência de carga (CT), com uma constante de interconversão altamente reversível (LE para o estado CT). Uma aplicação prática e moderna de armazenamento de energia química com, uma bateria redox de fluxo aquoso organometálico e exclusivamente orgânico com triptantrina sulfonada, trabalhando em pH neutro com estabilidade a longo prazo foi desenvolvida. Os testes de célula única demostraram ciclos de carga-descarga reprodutíveis, com melhores resultados no sistema exclusivamente orgânico, com eficiências coulômbica, voltaica e enérgicas estáveis e elevadas ao longo de vários ciclos. Este trabalho fornece uma nova perspetiva sobre o desenvolvimento de derivados da triptantrina solúveis em água com potencial aplicação em baterias de fluxo aquoso de sistemas exclusivamente orgânico que trabalham em pH neutro e são mais sustentáveis em termos ambientais.