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Yang, Luyi. "Batteries beyond Li-ion : an investigation of Li-Air and Li-S batteries". Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/384921/.
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VERSACI, DANIELE. "Materials for high energy Li-ion and post Li-ion batteries". Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2896992.
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Andersson, Anna. "Surface Phenomena in Li-Ion Batteries". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-5120-9/.
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Oltean, Alina. "Organic Negative Electrode Materials For Li-ion and Na-ion Batteries". Licentiate thesis, Uppsala universitet, Institutionen för kemi - Ångström, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-243273.
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Whitehead, Adam Harding. "Carbon-based negative electrodes for Li-ion batteries". Thesis, University of Southampton, 1997. https://eprints.soton.ac.uk/394278/.
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Ruggeri, Irene <1989>. "Beyond Li-ion batteries: novel concepts and designs". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8763/1/Thesis_IR.pdf.
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Efforts are being globally spent today to boost stored energy produced by renewable sources and to encourage a sustainable electric transportation. High-energy conversion systems like batteries can satisfy these demands in an efficient way. Although Li-ion batteries (LIBs) are the best batteries on the market in terms of energy content, a drastic change is desirable to increase both energy and power performance. In this context, Li/O2 is the next generation system due to the theoretical 10-fold higher specific energy than commercial LIBs (3500 vs. 250 Wh kg-1).
The aim of this PhD thesis is the development of novel concepts and cell designs with the purpose to increase the performance of the aprotic Li and Li/O2 batteries.
Specifically, a novel design of electrolyte (i.e. solvent-in-salt “SIS” solutions, where the salt-to-solvent ratio is higher than 1), and an innovative concept of semi-solid lithium redox flow air (O2) battery (SLRFAB) technology, based on the use of a O2-saturated semi-solid catholyte, have been proposed.
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VERGORI, ELENA. "Li-ion batteries monitoring for electrified vehicles applications". Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2839860.
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Fleury, Xavier. "Corrélation entre dégradation des composants internes et sécurité de fonctionnement des batteries Li-ion". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI060/document.
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Les batteries lithium-ion sont présentes dans de nombreuses applications portables ou embarquées car leurs énergies massique et volumique et leur cyclabilité les placent en tête des autres technologies de stockage. Cependant, elles ne résistent pas aux fonctionnements abusifs et peuvent subir des emballements thermiques avec risque d’explosion. Par ailleurs, l’état des composants internes évoluant au cours du vieillissement de la batterie, son comportement en sécurité doit être considéré pour n'importe quel état de santé afin de mieux concevoir la gestion thermique des cellules et du pack batterie. Dans ce contexte, il est donc primordial de comprendre les mécanismes de dégradation de l’ensemble des composants internes d’un élément (matériaux d'électrodes, collecteurs, séparateur et électrolyte) lors d’un vieillissement en fonctionnement normal et le déroulement des évènements en conditions abusives pouvant aboutir à un scénario accidentel.Le séparateur doit alors être considéré comme le premier dispositif de sécurité intrinsèque car il assure la séparation physique entre l’électrode positive et négative. Il doit alors être étudié sur le plan de ses propriétés électrochimiques, mécaniques et thermiques. Pour cela, une méthodologie de caractérisation a été développée, mettant en œuvre un large panel de techniques de caractérisation physique et chimique, et appliquée sur des séparateurs issus de vieillissements en conditions normales et après surcharge. Différentes méthodes de lavage ont permis de discréditer l’évolution morphologique et électrochimique du polymère poreux sans l’interaction des résidus solides associées aux produits de dégradation de l’électrolyte. Ainsi, la porosité et la tortuosité de la matrice polymère, associées à la conductivité ionique du système séparateur/électrolyte, ont été pleinement étudiées.Il a pu être montré que, en accord avec la croissance de la SEI sur l’électrode négative graphite, sa porosité de surface se dégrade avec un encrassement des pores par accumulation de composés solides de la SEI. Aucune conséquence sur les propriétés mécaniques n’a été observée, mais les performances électrochimiques en puissance se dégradent fortement. Une évaluation face aux risques de court-circuit interne par percée dendritique a permis de montrer que la formation de dendrite est favorisée. Le séparateur en tant qu’organe de sécurité face aux risques mécaniques garde donc son efficacité tout au long de la vie de la batterie lithium-ion mais le risque de court-circuit est plus élevéLithium-ion batteries have undeniable assets to meet several of the requirements for embedded applications. They provide high energy density and long cycle life. Nevertheless, they can face irreversible damage during their lives which could cause safety issues like the thermal runaway of the battery and its explosion. It is then essential to understand the degradation mechanisms of all the internal components of an accumulator (i.e. electrode materials, collectors, separator and electrolyte) and the progress of events in abusive conditions that can lead to an accident scenario. The aim of this thesis is to work on the security aspects of Lithium-ion batteries in order to understand these degradation mechanisms and to help to prevent future incidents.Even if the degradation mechanisms of all the internal components are studied in this work, a special attention is given to the separator. This component is indeed one of the most important safety devices of a battery and have to be electrochemically, mechanically and thermally characterized after ageing. Different washing methods have been study in order to characterize the separator without any degradation product of the electrolyte which could interfere. Porosity and tortuosity associated with the ionic conductivity of the separator have been tested.The results show that even if the separator is electrochemically inactive, its porosity can decrease because of the degradation of the negative graphite electrode. Indeed, SEI components obstruct the surface porosity of the separator. This porosity change do not cause any mechanical degradation but decrease separator performances at high current rate and promote lithium dendrite growth
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Perre, Emilie. "Nano-structured 3D Electrodes for Li-ion Micro-batteries". Doctoral thesis, Uppsala universitet, Institutionen för materialkemi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-119485.
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A new challenging application for Li-ion battery has arisen from the rapid development of micro-electronics. Powering Micro-ElectroMechanical Systems (MEMS) such as autonomous smart-dust nodes using conventional Li-ion batteries is not possible. It is not only new batteries based on new materials but there is also a need of modifying the actual battery design. In this context, the conception of 3D nano-architectured Li-ion batteries is explored. There are several micro-battery concepts that are studied; however in this thesis, the focus is concentrated on one particular architecture that can be described as the successive deposition of battery components (active material, electrolyte, active material) on free-standing arrays of nano-sized columns of a current collector. After a brief introduction about Li-ion batteries and 3D micro-batteries, the electrodeposition of Al through an alumina template using an ionic liquid electrolyte to form free-standing columns of Al current collector is described. The crucial deposition parameters influencing the nucleation and growth of the Al nano-rods are discussed. The deposition of active electrode material on the nano-structured current collector columns is described for 2 distinct active materials deposited using different techniques. Deposition of TiO2 using Atomic Layer Deposition (ALD) as active material on top of the nano-structured Al is also presented. The obtained deposits present high uniformity and high covering of the specific surface of the current collector. When cycled versus lithium and compared to planar electrodes, an increase of the capacity was proven to be directly proportional to the specific area gained from shifting from a 2D to a 3D construction. Cu2Sb 3D electrodes were prepared by the electrodeposition of Sb onto a nano-structured Cu current collector followed by an annealing step forcing the alloying between the current collector and Sb. The volume expansion observed during Sb alloying with Li is buffered by the Cu matrix and thus the electrode stability is greatly enhanced (from only 20 cycles to more than 120 cycles). Finally, the deposition of a hybrid polymer electrolyte onto the developed 3D electrodes is presented. Even though the deposition is not conformal and that issues of capacity fading need to be addressed, preliminary results attest that it is possible to cycle the obtained 3D electrode-electrolyte versus lithium without the appearance of short-circuits.
10
Gullbrekken, Øystein. "Thermal characterisation of anode materials for Li-ion batteries". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19224.
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Coin cells with lithium and graphite electrodes were assembled using different combinations of graphite material and electrolyte. Specifically, three commercially available graphite materials and five electrolyte compositions were studied. The cells were discharge-charge cycled with varying parameters in order to determine the performance of the graphite materials and electrolytes. Particularly, a temperature chamber was employed to cycle some cells at temperatures between 0 and 40°C to find the significance of the electrolyte composition and graphite material on the cell performance at these temperatures. The cycled cells were disassembled and samples from the graphite electrode soaked with electrolyte were prepared for thermal analysis, specifically differential scanning calorimetry (DSC). The thermal stability of the graphite electrodes and the influence from the graphite and electrolyte properties and the cycling parameters were analysed. In order to facilitate the interpretation of the results from discharge-charge cycling at different temperatures, DSC analysis from -80 to +50°C was performed on the pure electrolytes.Confirming previous studies, it was found that both the thermal stability and cycling performance were highly influenced by the properties of a solid electrolyte interphase (SEI), situated between the graphite surface and the electrolyte and formed during cycling. The three graphites were good substrates for stable SEI formation, exhibited by high thermal stability after being cycled at room temperature. After cycling with a temperature program, subjecting the cells to temperatures between 0 and 40°C, the thermal stability was generally reduced. This was attributed to increased SEI formation. The properties of both the electrolyte and graphite influenced the SEI and consequent thermal stability, though in different ways.The cell capacity was considerably reduced upon cycling at lower temperatures, such as 10 and 0°C. The results indicate that the electrolyte properties, particularly the viscosity and resulting conductivity, played the most important role in determining the cell performance. Low viscosity electrolyte components should be utilised, maintaining the electrolyte conductivity even at reduced temperatures. The graphite properties did not influence the cell performance at the temperatures studied. Advice is given on which electrolyte components should be avoided to build Li-ion cells performing acceptably at temperatures from 0 to 40°C.
11
Berti, Nicola. "MgH2-TiH2 hydrides as negative electrodesof Li-ion batteries". Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1029/document.
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Les batteries lithium-ion sont aujourd’hui très utilisées pour alimenter l’électronique portable telle que les ordinateurs, les smartphones et les caméras. Cependant, de nouvelles applications telles que les véhicules électriques et les systèmes stationnaires de stockage d'énergie nécessitent des batteries à performances améliorées. En particulier, de nouveaux matériaux d'électrode avec des densités d'énergie plus élevées sont requis. Les hydrures de MgH2 et TiH2 et leurs mélanges possèdent de très fortes capacités électrochimiques (>1 Ah/g). Ils ont été étudiés comme matériaux d’électrode négative dans les batteries Li-ion. La réaction de conversion de ces hydrures avec du lithium et les changements structuraux induits ont été étudiés en détails pour mieux comprendre les mécanismes réactionnels et leur réversibilité. Les propriétés électrochimiques de couches minces de MgH2 et des poudres composites de MgH2+TiH2 ont été étudiées en utilisant à la fois des électrolytes organiques liquides et un électrolyte solide LiBH4. La capacité réversible et la tenue au cyclage dépendent fortement du rapport molaire entre les deux hydrures et des conditions de cyclage. Le transport de masse et la densité d’interfaces à l'intérieur de l'électrode sont identifiés comme les principaux facteurs affectant la réversibilité de la réaction de conversionToday, lithium-ion batteries are widely used as power supplies in portable electronics such as laptops, smartphones and cameras. However, new applications such as full electric vehicles and energy storage stationary systems require enhanced battery performances. In particular, novel electrode materials with higher energy density are needed.MgH2 and TiH2 hydrides and mixtures of them have high electrochemical capacity (> 1 Ah/g). They have been studied as negative electrode materials in Li-ion batteries. The conversion reaction of lithium with these hydrides and the related microstructural changes have been deeply investigated to gain a better understanding of reaction mechanisms and their reversibility. The electrochemical properties of MgH2 thin films and MgH2+TiH2 composite powders have been evaluated using both liquid organic and solid (LiBH4) electrolytes. Reversible capacity and cycle-life are found to strongly depend on both molar ratio between the hydrides and cycling conditions. Mass transport and density of interfaces within the electrode are identified as the main factors affecting the reversibility of the conversion reaction
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Hémery, Charles-Victor. "Etudes des phénomènes thermiques dans les batteries Li-ion". Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00968666.
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Les travaux présentés dans cette thèse concernent l'étude thermique des batteries Li-ion en vue d'une application de gestion thermique pour l'automobile. La compréhension des phénomènes thermiques à l'échelle accumulateur est indispensable avant de réaliser une approche de type module ou pack batterie. Ces phénomènes thermiques sont mis en évidence à partir d'une modélisation thermique globale de deux accumulateurs de différentes chimies, en décharge à courant constant. La complexité du caractère résistif de l'accumulateur Li-ion a mené au développement d'un modèle prenant en compte l'interaction entre les phénomènes électrochimiques et thermiques, permettant une approche prédictive de son comportement. Enfin la réalisation de deux boucles expérimentales, de simulation de systèmes de gestion thermique d'un module de batterie, montre les limites d'un refroidissement classique par air à respecter les critères de management thermique. En comparaison, le second système basé sur l'intégration innovante d'un matériau à changement de phase (MCP) se montre performant lors de situations usuelles, de défauts ou encore lors du besoin d'une charge rapide de la batterie.
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Zou, Haiyang. "Development of a Recycling Process for Li-Ion Batteries". Digital WPI, 2012. https://digitalcommons.wpi.edu/etd-theses/260.
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The rechargeable secondary Lithium ion (Li-ion) battery is expected to grow to more than $6.3 billion by 2012 from ~$4.6 billion in 2006. With the development of personnel electronics, hybrid and electric vehicles, Li-ion batteries will be more in demand. However, Li-ion batteries are not widely recycled because it is not economically justifiable (in contrast, at present more than 97% Lead-acid batteries are recycled). So far, no commercial methods are available to recycle different chemical Li-ion batteries economically and efficiently. Considering our limited resources, environmental impact, and national security, Li-ion batteries must be recycled. A new methodology with low temperature and high efficiency is proposed in order to recycle Li-ion batteries economically and with industrial viability. The separation and synthesis of cathode materials (most valuable in Li-ion batteries) from recycled components are the main focus of the proposed research. The analytical results showed that the recycling process is practical and has high recovery efficiency, create great commercial value as well.
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Vidal, Laveda Josefa. "Rational design of nanostructured electrodes for Li-ion batteries". Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/8051/.
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This thesis focuses on the rational design of fast and low temperature synthetic routes for the preparation of energy storage nanostructures with potential applications as electrode materials for Li-ion batteries. The materials synthesised in this work have been fully investigated by powder X-ray diffraction, electron microscopy and potentiodynamic measurements. Where possible, high resolution powder X-ray and neutron diffraction, X-ray and neutron pair distribution function (PDF) analysis and muon spin relaxation (µ+SR) studies have been conducted in order to have a better understanding of the structure-property relationship and have a complete and detailed characterisation of these battery materials. Chapter 1 includes a general introduction about Li-ion batteries and a brief analysis of the most promising electrode materials used in Li-ion batteries. Furthermore, a short description about different synthetic methodologies such as solid state, microwave-assisted and solvothermal syntheses is included. In particular, the benefits of single source precursor processes are highlighted. Finally, the main aims of this thesis are also discussed. The objective of Chapter 2 is to provide detailed experimental procedures of all materials synthesis and also to briefly describe the main characterisation techniques employed during this research, exploring in more detail those not commonly used, such as pair distribution function analysis and muon spin relaxation. In Chapter 3, a microwave-assisted solvothermal approach for the preparation of a family of LiFe1-xMnxPO4 (x=0, 0.25, 0.5, 0.75 and 1) olivines using commercial starting materials is presented. To fully characterise and have a deeper insight of the structure-property relationship of these nanocrystalline phases, high resolution powder neutron diffraction and neutron PDF analyses of these phases are conducted, allowing the examination of the local structure, cation distribution, presence of defects and Li content. Moreover, muon spin relaxation is used for the first time to investigate the lithium diffusion in this series of olivine mixed metal phosphate phases. By understanding how this double transition metal system operates, it may be possible to synthesise high performing electrode nanomaterials with higher energy density than LiFePO4 with no significant increase in cost and exhibiting charge/discharge rates acceptable for commercial applications. Chapter 4 covers a fast and energy-efficient synthetic route to olivine nanostructured LiFe1-xMnxPO4 cathodes and Mn3O4 hausmannite conversion anodes for Li-ion batteries using a new class of metal alkoxides containing one or two transition metals. The main advantage of metal alkoxides over commercially available inorganic salt mixtures is that the different metals of the final product are already present in a single precursor, which significantly reduces the energy required for reaction of a multicomponent precursor mixture employed in conventional synthesis. Furthermore, thermal decomposition of these metal alkoxide compounds can be performed at relatively low temperatures, allowing decreased temperatures during synthesis and making the process more energy efficient. This work intends to emphasise the versatility of metal alkoxide precursors in the preparation of nanostructured Li-ion battery materials for both positive and negative electrodes through relatively fast and low temperature microwave and ultrasound-assisted methods. In Chapter 5, having confirmed the suitability of employing transition metal alkoxide precursors for the preparation of nanostructured electrodes via microwave or ultrasound assisted methods, efforts have been directed to develop the synthesis of a series of heterometallic alkoxide complexes containing both Li and a transition metal (Fe, Mn). These heterometallic alkoxide precursors are then used for the generation of highly crystalline LiFe1-xMnxPO4 olivine nanostructures exhibiting an outstanding electrochemical performance. Co-location of all the required metals in these metallorganic precursors could bypass the need of diffusional mixing and allow the reactions to proceed faster and at lower temperatures generating better crystallised materials. X-ray PDF analyses of these LiFe1-xMnxPO4 olivine nanophases are conducted in an effort to examine the local structure, defect chemistry and show that microwave processes produce highly crystalline materials even after short reaction times. Finally, a ionothermal microwave-assisted synthesis of LiFePO4 nanoparticles using heterometallic alkoxide precursors has been examined in order to study the influence of the solvent in the resulting electrochemical performance. Chapter 6 explores the preparation of olivine LiFe1-xMnxPO4 nanostructures through conventional solvothermal processes using the same single source heterometallic alkoxide precursors. A reduction in particle size and an enhancement in the electrochemical behaviour are achieved when using single source precursor metallorganic compexes compared to commonly used commercial starting materials. Moreover, the fabrication of Fe3O4 magnetite nanoparticles by the room temperature hydrolysis of the [FeLi2Br(OtBu)4(THF)2]n heterometallic alkoxide precursor and its application as anode material for Li-ion batteries is presented. Chapter 7 further develops this family of heterometallic precursors by examining the preparation of olivine nanostructured Ni-doped LiFePO4 cathodes via microwave processes. The effect of the addition of polyvinylpyrrolidone (PVP) in the reaction mixture, which could act as a capping and dispersing agent to prevent particle growth and agglomeration as well as a possible carbon source for all-in-one carbon coating procedures, is investigated. The preparation of a Li and Ni containing metal alkoxide and its utilisation as a Ni precursor for the preparation of nanostructured LiFe1-xNixPO4 olivine cathodes and NiO conversion anodes is presented, demonstrating again the versatility of single source precursor synthesis using heterometallic alkoxides in the preparation of both Li-ion battery cathode and anode materials. Finally, Chapter 8 includes some general conclusions and an outlook for future work including some preliminary investigations on microwave syntheses of non-olivine β-LiFe1-xMxPO4 (M=Fe, Co, Ni) and maricite NaFe1-xMnxPO4 nanostructures for Li and Na-ion battery applications.
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Guerrini, Niccolò. "High capacity materials for next generation Li-ion batteries". Thesis, University of Oxford, 2018. https://ora.ox.ac.uk/objects/uuid:ab5f7a60-93c3-4044-8060-c2a0280a4ec7.
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With the staggering growth in the recent years of the Lithium Ion Batteries market and the large number of different applications, in which these devices are currently employed, a change of paradigm in terms of the active materials composing the electrodes in these batteries is required. To meet the market needs in terms of performance (energy density and power), safety and respect of the environment, non-toxic light materials with high capacities are highly sought after. The main goal of this work was to provide an insight into the mechanisms which limit the application of the Li-Rich based cathodes and hard carbon and silicon anodes. These high capacity materials would be ideal candidates to combine into a full cell for next generation batteries with enhanced energy densities. The mechanisms underpinning the electrochemical behaviour of a family of cobalt-free lithium-rich layered oxide cathodes, with general formula Li(4/3-2/3x)NixMn(2/3-1/3x)O2 (0 ≤ x ≤ 0.3), has been unravelled. Initially, Li1.2Ni0.2Mn0.6O2 was synthesized via a one-pot synthetic route and studied to understand the origin of the high potential plateau appearing over the first charge. Thanks to a careful structural and electrochemical characterization and powerful spectroscopic techniques (XANES, SXAS, RIXS) the presence of reversible anionic redox activity has been demonstrated. Subsequently the focus of the work has moved on to unravelling the role of the nickel substitution in favouring the oxygen redox activity over the oxygen loss phenomenon for this family of materials. In parallel, a study on the improvement of the cyclability and efficiency of high capacity silicon-based anodes has been carried out using new polymeric binders, some of which, have been shown to guarantee more stable cycling and higher capacities with respect to the established binder sodium carboxymethylcellulose (Na-CMC). Additionally, in the attempt to address the issue concerning the First cycle Irreversible Capacity (FIC) of the silicon anodes, a highly reducing pre-treatment has been performed on the electrodes. As well, the treatment has been tested on hard carbon anodes that, despite being promising materials for Lithium and also Sodium Ion Batteries, are usually plagued by large FIC. An important improvement in terms of coulombic efficiency at the beginning of cycling has been observed in all the tested materials without any sign of detrimental effects on the electrodes overall performance.
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FUGATTINI, Silvio. "Binder-free porous germanium anode for Li-ion batteries". Doctoral thesis, Università degli studi di Ferrara, 2019. http://hdl.handle.net/11392/2488081.
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To develop high energy density lithium ion batteries, the use of new electrode
materials is required. Germanium is among the possible alternatives to the most
commonly used anode, graphite (372 mAh/g), thanks to its four-times higher
theoretical gravimetric capacity (1600 mAh/g).
Here is presented a two-step method to produce a binder-free porous germanium
anode, depositing the semiconductor on metallic substrates by means of Plasma
Enhanced Chemical Vapour Deposition (PECVD) and subsequently performing
an electrochemical etching with hydrofluoric acid to create a porous structure.
The Ge-based electrode attained a capacity of 1250 mAh/g at a current rate of
1C (1C=1600 mA/g) and retained a stable capacity above 1100 mAh/g for more
than 1000 cycles tested at different C-rates up to 5C.
Both deposition and etching techniques are scalable for industrial production,
whose fields of application could be aerospace or medical applications, due to the
high cost of germanium as a raw material.Per sviluppare batterie agli ioni di litio ad alta densità energetica, è necessario l’utilizzo di nuovi materiali elettrodici. Il germanio è una delle possibili alternative all’anodo più comunemente impiegato, la grafite (372 mAh/g), grazie alla sua capacità gravimetrica teorica quattro volte maggiore (1600 mAh/g). In questo lavoro viene presentato un processo in due fasi per realizzare un anodo in germanio poroso privo di legante (binder), realizzando film di semiconduttore su substrati metallici mediante deposizione chimica da fase vapore assisitita da plasma (PECVD) ed effettuando successivamente un attacco elettrochimico con acido fluoridrico per creare una struttura porosa. L’elettrodo in germanio poroso ha raggiunto una capacità di 1250 mAh/g ad una velocità di carica/scarica pari ad 1C (1C = 1600 mA/g) mantenendo, inoltre, una capacità stabilmente superiore a 1100 mAh/g per più di 1000 cicli a diversi C-rate fino a 5C. Sia la tecnica di deposizione che quella di attacco chimico sono scalabili per la produzione industriale, i cui possibili campi di applicazione sono il settore aerospaziale o medico, a causa dell’elevato costo del germanio come materia prima.
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Joulié, Marion. "Mécanisme de dissolution de matériaux actifs d'électrodes de type LiNi1/3Mn1/3Co1/3O2 d'accumulateurs Li-ion en vue de leur recyclage". Thesis, Montpellier, Ecole nationale supérieure de chimie, 2015. http://www.theses.fr/2015ENCM0011/document.
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La voie hydrométallugique représente une alternative pour la récupération des métaux de valeur tels que le nickel et le cobalt contenus dans les batteries Li-ion usagées. La première étape du procédé hydrométallurgique, l'étape de lixiviation a été optimisée grâce à l'étude du comportement du matériau actif d'électrode positive LiNi1/3Mn1/3Co1/3O2 (NMC) qui s'avère être le candidat idéal pour les batteries de véhicules électriques. Tout d'abord, l'étude des aspects thermodynamiques de la réaction de dissolution a permis de prédire le comportement du NMC dans divers acides. Puis, l'approche cinétique a conduit à l'élucidation du mécanisme se produisant lors de l'étape de lixiviation et à la mise en évidence de l'étape cinétiquement déterminante de la dissolution. Ce mécanisme a par la suite été généralisé aux autres matériaux couramment rencontrés dans les batteries Li-ion. L'impact d'agents réducteurs minéraux, organiques et métalliques pour promouvoir la dissolution du NMC a été évalué. Cette approche compare l'effet de réactifs à faible (acides sulfurique et chlorhydrique) et fort (acides citrique, oxalique et formique et peroxyde d'hydrogène) pouvoir réducteur ainsi que celui du cuivre et de l'aluminium provenant des collecteurs de courants des batteries Li-ion. Cette étude soulève le fort intérêt de l'emploi des collecteurs de courant présents de manière inhérente dans la fraction traitée par hydrométallurgieBasic hydrometallurgical routes represent an alternative to recover valuable metals such as nickel and cobalt from spent Li-ion batteries. The first step of hydrometallurgical process, lixiviation step is optimized by studying the behaviour of LiNi1/3Mn1/3Co1/3O2 (NMC) positive electrode active material, due to its good performances which make it an adequate candidate for the electric vehicles. First of all, the study of thermodynamic aspects allows predicting the behaviour of NMC material in various acidic media. Then, the kinetic approach leads to define the mechanism occurring during the leaching step and to outline the rate-limiting step of the dissolution. The reductive effect of mineral, organic and metallic reducing agents to promote leaching of NMC material is evaluated. The approach comparatively evaluates the reducing power impact of weak (sulfuric and hydrochloric acids), strong reducing agents (citric, oxalic and formic acids and hydrogen peroxide) and copper and aluminum from Li-ion batteries current collectors. This work points out the strong interest to advantageously use current collectors inherently present in the fraction treated by hydrometallurgy
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Rosina, Kenneth. "Structural and electrochemical investigation of aluminum fluoride coated Li[Li₁/₉Ni₁/₃Mn₅/₉]O₂ cathodes for secondary Li-ion batteries". Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708756.
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Ranque, Pierre. "New polymers as binders or electroactive materials for Li-ion batteries". Thesis, Pau, 2018. http://www.theses.fr/2018PAUU3016/document.
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Ce travail de thèse, débuté en 2015, a pour but de développer et d'étudier les propriétés de nouveaux liants polymères pour batteries Li-ion. Les synthèses organiques ainsi que leurs caractérisations associées et les tests électrochimiques ont été réalisées à Delft. Puis, des études de spectroscopie photo-électronique par rayons X (XPS) ont été réalisées à Pau pour déterminer et comprendre la réactivité de certain de ces nouveaux matériaux vis-à-vis du lithiumThis PhD work started in 2015, aimed to develop and investigate the properties of new polymers as binders for Li-ion batteries. Organic syntheses with associated characterizations and electrochemical tests were performed in Delft. Then, X-ray photoelectron spectroscopy studies were performed in Pau, to determine and understand the reactivity of some of these new materials toward lithium ions in coin cells
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Bolloli, Marco. "Nouvelles membrane polymères et électrolytes liquides pour batteries Li-ion". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI110/document.
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Les batteries Li-ion sont la technologie de référence pour l'électronique portable, et l'un des objectifs est le développement de cette technologie pour des applications demandant de fortes densités d'énergie, comme la traction. Ce travail, mené dans le cadre du projet Européen AMELIE- Green Car, porte sur deux aspects. Le premier concerne la synthèse et la caractérisation de nouveaux solvants et sels performants et pouvant être utilisés avec des matériaux à haut potentiel tels que LiNi1/3Mn1/3Co1/3O2 ou LiNi0,4Mn1,6O4, en remplacement des électrolytes courants à base de LiPF6 et de carbonates, qui induisent une forte d'autodécharge et présentent des stabilités thermique et chimique insuffisantes. L'utilisation de carbonates, carbamates et sulfonamides fluorés en tant que solvants, permet d'obtenir, pour certaines des formulations évaluées, des performances comparables aux références commerciales, malgré des conductivités inférieures. De plus, la fluoration confère à ces molécules des stabilités thermique et électrochimique améliorées. En ce qui concerne les sels, plusieurs nouvelles structures ont été synthétisées et testées en combinaison avec des solvants commerciaux, avec des résultats intéressants du point de vue de la conductivité et du comportement électrochimique.La deuxième partie de ce travail concerne la mise en forme, par des procédés industriels, de séparateurs minces à base de polymères fluorés, qui présentent des performances comparables aux séparateurs commerciaux. Des membranes denses et poreuses ont été élaborées à partir de plusieurs grades de PVDF. Les membranes poreuses élaborées, présentant des taux de porosité élevés, montrent de faibles tenues mécaniques, deux stratégies de renfort ont ainsi été étudiées : la première via la réticulation des membranes après greffage de groupements polymérisables, la deuxième via l'incorporation de Cellulose Nano Cristalline (CNC), formant un réseau percolant permettant le renfort. Les deux méthodes ont donné des résultats prometteurs sur les membranes denses : le module de conservation augmente entre 2 et 5 fois à 25°C tout en conservant des performances électrochimiques intéressantes. Le transfert de ces propriétés aux membranes poreuses est encore à optimiser ; cependant un renfort partiel a été obtenu pour les membranes composites poreuses, ce qui en fait, en combinaison avec une bonne conductivité (largement au dessus de 1mS/cm) et porosité, des candidats attractifs pour des accumulateurs Li-ion à charge rapideLi-ion batteries have become the dominant power storage devices for portable electronics, and researchers are still at work to broaden their field of use to high energy density devices, like cars. Within the framework of the collaborative project AMELIE - Green car, this study articulates along 2 main axes. The first one deals with the synthesis and characterization of new fluorinated solvents and salts to replace, for the use with high potential materials such as LiNi1/3Mn1/3Co1/3O2 or LiNi0,4Mn1,6O4, the commonly used LiPF6 and carbonate-based electrolytes, which suffer from a high self-discharge ratio, and an insufficient thermal and chemical stability. The use of fluorinated carbonates, carbamates, and sulfonamides as solvents provides performances as good as the commercial references, even if we register a visible loss in conductivity. Moreover, the fluorination provides these molecules with higher thermal and electrochemical stabilities. About the salts, several new structures of sulfonamide salts were synthesized and tested in combination with commercial solvents, with interesting results from the point of view of conductivity and the electrochemical stability.The second part of this study deals with the development of thin perfluorinated separators, which could compete with commercial references such as Celgard® separators and whose production could be easily up-scale. To do this, dense and porous separators were prepared from several PVdF grades. Since the porous membranes, the most promising for the battery applications, suffer from a relatively low mechanical strength, 2 reinforcement techniques were also evaluated: the first one consists in cross-linking the polymer after grafting of polymerizable groups; the second one consists in adding Nano Cristalline Cellulose (NCC) particles to form a reinforcing percolating network. Both methods give promising results with dense membranes: a 2- to 5-fold increase of storage modulus is observed at 25°C, in addition to interesting electrochemical properties. The transfer of these promising results to the porous membranes is still to be optimized, but a partial reinforcement was obtained for nano-composites porous membranes, while the good conductivity (still largely superior to 1 mS/cm) and porosity make them attractive options for high charge rate batteries
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Beaulieu, Luc Yvon. "Mechanically alloyed Sn-Mn-C anodes for Li-ion batteries". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0016/MQ57272.pdf.
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Li, Jun-Tao. "Investigation of electrode/Electrolyte interfacial reactions for Li Ion batteries". Paris 6, 2010. http://www.theses.fr/2010PA066301.
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Les performances et la sécurité des batteries Li-ions dépendent fortement de la structure et des processus se produisant aux interfaces entre électrodes et électrolyte non aqueux. En comparaison des efforts dédiés à la synthèse et aux performances de nouveaux matériaux d’électrode, les processus interfaciaux se produisant sur ces matériaux doit être étudiés de façon approfondie. L’objet de ce mémoire a été de développer l’application des techniques analytiques FTIRS, EQCM, XPS et ToF-SIMS à l’étude des réactions interfaciales sur des anodes en couche mince de Sn, d’alliage Sn-Co, de graphite et de Cr2O3.
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BOZ, BUKET. "Complementary experiments, modelling, and simulations of innovative-li-ion batteries". Doctoral thesis, Università degli studi di Brescia, 2021. http://hdl.handle.net/11379/544081.
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Di, Censo Davide. "New electrolytes for high power Li-ion batteries : electrochemical stability, Li-ion insertion kinetics and corrosion inhibition properties /". [S.l.] : [s.n.], 2005. http://library.epfl.ch/theses/?nr=3205.
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Liu, Mengxin. "Studies of Ionic Liquid Hybrids: Characteristics and Their Potential Application to Li-ion Batteries and Li-ion Capacitors". Wright State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=wright1503064504631567.
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Jabbour, Lara. "Utilisation de procédés papetiers et de fibres cellulosiques pour l'élaboration de batteries Li-ion Elaboration of Li-ion batteries using cellulose fibers and papermaking techniques". Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00998372.
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L'objectif du travail décrit dans cette thèse est de développer des batteries Li-ion peu coûteuses, respectueuses de l'environnement, facilement industrialisables et recyclables, tout en utilisant des fibres cellulosiques et un procédé en milieu aqueux. Deux approches ont été adoptées pendant ce travail expérimental. Dans un premier temps, les microfibrilles de cellulose ont été utilisées pour la production d'anodes par un procédé de casting. Puis, une approche papetière a été adoptée. La plupart des travaux expérimentaux se sont focalisés sur l'utilisation de fibres de cellulose pour la production d'électrodes papier (anodes et cathodes) et de séparateurs-papier par procédé de filtration en milieu aqueux pour obtenir des cellules complètes à base de cellulose. Les électrodes obtenues sont homogènes, souples et leurs propriétés électrochimiques comparables à celles d'électrodes de références utilisant un polymère de synthèse comme liant.
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Bhandari, Sarita. "Characterization and Modeling of NiZn and Li-based Batteries". University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1335932763.
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Abada, Sara. "Compréhension et modélisation de l'emballement thermique de batteries Li-ion neuves et vieillies". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066684/document.
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Les batteries lithium-ion s'affichent comme de bons candidats pour assurer le stockage réversible de l'énergie électrique sous forme électrochimique. Toutefois, elles sont à l'origine d'un certain nombre d'incidents aux conséquences plus ou moins dramatiques. Ces incidents sont souvent liés au phénomène d'emballement thermique. La sécurité des batteries Li-ion représente par conséquent un enjeu technique et sociétal très important. C'est dans ce contexte que vient s'inscrire ce travail de thèse dans le cadre d'une collaboration entre IFPEN, l'INERIS et le LISE. Une double approche de modélisation et expérimentation a été retenue. Un modèle 3D du comportement thermique a été développé à l'échelle de la cellule, couplant les phénomènes thermiques et chimiques, et prenant en compte le vieillissement par croissance de la SEI sur l'électrode négative. Le modèle a été calibré pour la chimie LFP/C sur deux technologies A123s (2,3 Ah) et LifeBatt (15 Ah), puis validé expérimentalement. Le modèle permet d'identifier les paramètres critiques d'emballement de cellules, il permet également de discuter l'effet du vieillissement sur l'emballement thermique. Grâce à l'expérimentation, les connaissances en termes d'amorçage et de déroulement d'un emballement thermique d'une batterie Li-ion, ont pu être enrichies, en particulier pour les cellules commerciales LFP/C cylindriques A123s, LifeBatt, et pour les cellules NMC/C prismatiques en sachet souple PurePower (30 Ah). Cette étude ouvre de nouvelles possibilités pour améliorer la prédiction des différents événements qui ont lieu lors de l'emballement thermique des batteries Li-ion, à différentes échellesLi-ion secondary batteries are currently the preferred solution to store energy since a decade for stationary applications or electrical traction. However, because of their safety issues, Li-ion batteries are still considered as a critical part. Thermal runaway has been identified as a major concern with Li-ion battery safety. In this context, IFPEN, INERIS and LISE launched a collaboration to promote a PhD thesis so called « understanding and modeling of thermal runaway events pertaining to new and aged Li-ion batteries ». To achieve this goal, a double approach with modeling and experimental investigation is used. A 3D thermal runaway model is developed at cell level, coupling thermal and chemical phenomena, and taking into account the growth of the SEI layer as main ageing mechanism on negative electrode. Advanced knowledge of cells thermal behavior in over-heated conditions is obtained particularly for commercial LFP / C cylindrical cells: A123s (2,3Ah), LifeBatt (15Ah), and NMC / C pouch cells: PurePower (30 Ah). The model was calibrated for LFP / C cells, and then it was validated with thermal abuse tests on A123s and LifeBatt cells. This model is helpful to study the influence of cell geometry, external conditions, and even ageing on the thermal runaway initiation and propagation. This study opens up new possibilities for improving the prediction of various events taking place during Li-ion batteries thermal runaway, at various scales for further practical applications for safety management of LIBs
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Bianchini, Matteo. "In situ diffraction studies of electrode materials for Li-ion and Na-ion batteries". Thesis, Amiens, 2015. http://www.theses.fr/2015AMIE0022/document.
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Ce travail vise à étudier les matériaux d'électrodes pour batteries Li-ion et Na-ion lors qu’ils fonctionnent à l'intérieur des batteries. Afin de comprendre l'évolution structurelle des matériaux alors que les ions Li+ ou Na+ sont insérés/extraits de leur cadre, on utilise principalement la diffraction, exploitant neutrons, rayons X et le rayonnement synchrotron (SR). Nous avons adopté une approche combinée des mesures ex situ, in situ et operando. Au début, nous avons conçu une cellule électrochimique pour mesures in situ de diffraction de neutrons sur poudre (NPD), avec un alliage en (Ti,Zr) "transparent aux neutrons"; cette cellule s'est ajoutée à l’ensemble de nos outils pour effectuer des études de type operando. Nous avons démontré leur faisabilité en utilisant LiFePO4, montrant de bonnes performances électrochimiques et des données NPD de haute qualité pour affinements structurales Rietveld. Ensuite, nous avons réalisé des études des spinelles Li1+xMn2-xO4 (x=0,0.05,0.10) et LiNi0.4Mn1.6O4: pendant le cyclage, nous avons rapporté des évolutions structurelles, des diagrammes de phases et paramètres subtils tels que le comportement du Li, ou les facteurs de température. L’utilisation complémentaire du SR a clarifié la nature de la phase ordonnée Li0.5Mn2O4. Nos études combinées ont concernées d’autres matériaux d'électrodes prometteurs: LiVPO4O et Na3V2(PO4)2F3. Les 2 révèle des comportements complexes pendant la (de)intercalation du Li+/Na+. Les données de haute qualité ont permis des analyses quantitatives, dévoilant la structure d'un grand nombre des phases ordonnées et menant à la compréhension du comportement des cations dans ces matériauxThis work aims at studying electrode materials for Li-ion and Na-ion batteries as they function inside batteries. Diffraction is the mainly used technique, exploiting neutrons, X-Rays and synchrotron radiation (SR), to obtain insights on the structural evolution of such materials as Li+ or Na+ are inserted/extracted from their framework. We adopted a combined approach of ex situ, in situ and operando measurements to extract a maximum of information from our studies. At first, we designed an electrochemical cell for in situ neutron powder diffraction (NPD) measurements, featuring a “neutron-transparent” (Ti,Zr) alloy; this cell, joined to others previously developed in our group, gave us a complete set of tools to perform our studies. We demonstrated the feasibility of operando NPD using LiFePO4, showing good electrochemical performances and high-quality NPD patterns for Rietveld structural refinements. Then we carried out detailed studies of spinels Li1+xMn2-xO4 (x = 0, 0.05, 0.10) and LiNi0.4Mn1.6O4: we reported phase diagrams, structural evolutions and subtle parameters as lithium's behavior inside the spinel framework, or thermal displacement parameters, directly upon cycling. Complementary use of SR shed light on other features, as the nature of the ordered phase Li0.5Mn2O4. Our combined studies concerned other promising electrode materials: LiVPO4O and Na3V2(PO¬4)2F3. Both revealed complex behaviors upon Li+/Na+
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Zhao, Kejie. "Mechanics of Electrodes in Lithium-Ion Batteries". Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10551.
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This thesis investigates the mechanical behavior of electrodes in Li-ion batteries. Each electrode in a Li-ion battery consists of host atoms and guest atoms (Li atoms). The host atoms form a framework, into which Li atoms are inserted via chemical reactions. During charge and discharge, the amount of Li in the electrode varies substantially, and the host framework deforms. The deformation induces in an electrode a field of stress, which may lead to fracture or morphological change. Such mechanical degradation over lithiation cycles can cause the capacity to fade substantially in a commercial battery. We study fracture of elastic electrodes caused by fast charging using a combination of diffusion kinetics and fracture mechanics. A theory is outlined to investigate how material properties, electrode particle size, and charging rate affect fracture of electrodes in Li-ion batteries. We model an inelastic host of Li by considering diffusion, elastic-plastic deformation, and fracture. The model shows that fracture is averted for a small and soft host—an inelastic host of a small feature size and low yield strength. We present a model of concurrent reaction and plasticity during lithiation of crystalline silicon electrodes. It accounts for observed lithiated silicon of anisotropic morphologies. We further explore the microscopic deformation mechanism of lithiated silicon based on first-principles calculations. We attribute to the microscopic mechanism of large plastic deformation to continuous Li-assisted breaking and reforming of Si-Si bonds. In addition, we model the evolution of the biaxial stress in an amorphous Si thin film electrode during lithiation cycle. We find that both the atomic insertion driven by the chemomechanical load and plasticity driven by the mechanical load contribute to reactive flow of lithiated silicon. In such concurrent process, the lithiation reaction promotes plastic deformation by lowering the stress needed to flow. Li-ion battery is an emerging field that couples electrochemistry and mechanics. This thesis aims to understand the deformation mechanism, stresses and fracture associated with the lithiation reaction in Li-ion batteries, and hopes to provide insight on the generic phenomenon that involves interactive chemical reactions and mechanics.Engineering and Applied Sciences
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Wood, Stephen. "Computer modelling studies of new electrode materials for rechargeable batteries". Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687357.
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Developing a sustainable energy infrastructure for the 21st century requires the large scale development of renewable energy resources. Fully exploiting these inherently intermittent supplies will require advanced energy storage technologies, with rechargeable Li-ion and Na-ion batteries considered highly promising for both vehicle electrification and grid storage applications. However, the performance required of battery materials has not been achieved, and significant improvements are needed. Modern computational techniques allow the elucidation of structure-property relationships at the atomic level and are valuable tools in providing fundamental insights into novel materials. Therefore, in this thesis a combination of atomistic simulation and ab initio density functional theory (DFT) techniques have been used to study a number of potential battery cathode materials. Firstly, Na2FePO4F and NaFePO4 are interesting materials that have been reported recently as attractive positive electrodes for Na-ion batteries. Here, we report their Na-ion conduction behaviour and intrinsic defect properties using atomistic simulation methods. Na+ ion conduction in Na2FePO4F is predicted to be two-dimensional (2D) in the interlayer plane. Na ion migration in NaFePO4 is restricted to the [010] direction along a curved trajectory, leading to quasi-1D Na+ diffusion. Furthermore, Na/Fe antisite defects are predicted to have a lower formation energy in NaFePO4 than Na2FePO4F. The higher probability of tunnel occupation with a relatively immobile Fe2+ cation - along with a greater volume change on redox cycling - contributes to the poor electrochemical performance of NaFePO4. Secondly, work on the Na2FePO4F system is extended to include investigation of the surface structures and energetics. The equilibrium morphology is found to be essentially octagonal, compressed slightly along the [010] direction, and is dominated by the (010), (021), (122) and (110) surfaces. The calculated growth morphology is a more ``rod-like'' nanoparticle, with the (021), (023), (110) and (112) planes predominant. The (010) surface lies parallel to the Na layers in the ac plane and is unlikely to facilitate Na+ intercalation. As such, its prominence in the equilibrium morphology, and absence from the growth morphology, suggests nanoparticles synthesised in a kinetically limited regime should provide higher rate performance than those synthesised in close to equilibrium conditions. Surface redox potentials for Na2FePO4F derived using DFT vary between 2.76 - 3.37 V, in comparison to a calculated bulk cell voltage of 2.91 V. Most significantly, the lowest energy potentials are found for the (130) and (001) planes suggesting that upon charging Na+ will first be extracted from these surfaces, and inserted lastly upon discharging. Thirdly, the mixed phosphates Na4M3(PO4)2P2O7 (M=Fe, Mn, Co, Ni) are explored as a fascinating new class of materials reported to be attractive Na-ion cathodes, displaying low volume changes upon cycling indicative of long lifetime operation. Key issues surrounding intrinsic defects, Na-ion migration mechanisms and voltage trends have been investigated through a combination of atomistic energy minimisation, molecular dynamics and DFT simulations. The MD results suggest Na+ diffusion extends across a 3D network of migration pathways with an activation barrier of 0.20-0.24 eV, and diffusion coefficients (DNa) of 10-10-10-11 cm2s-1 at 325 K, suggesting high rate capability. The cell voltage trends, explored using DFT methods, indicate that doping the Fe-based cathode with Ni can significantly increase the voltage, and hence energy density. Finally, DFT simulations of K+-stabilised α-MnO2 have been combined with aberration corrected-STEM techniques to study the surface energetics, particle morphologies and growth mechanism. α-K0.25MnO2 grown through a hydrothermal synthesis method is found to produce primary nanowires with preferential growth along the [001] direction. Primary nanowires attach through a shared (110) interface to form larger secondary nanowires. This is in agreement with DFT simulations with the {100}, {110} and {211} surfaces displaying the lowest surface energies. The ranking of surface energies is driven by Mn coordination environments and surface relaxation. The calculated equilibrium morphology of α-K0.25MnO2 is consistent with the observed primary nanowires from high resolution electron microscopy images.
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Liu, Hao. "Understanding two-phase reaction processes in electrodes for Li-ion batteries". Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709262.
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Hapuarachchi, Sashini Neushika Sue. "Fabrication and characterization of silicon based electrodes for Li-ion batteries". Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/207430/1/Sashini_Hapuarachchi_Thesis.pdf.
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This thesis presents the synthesis and characterization of silicon electrodes to address critical challenges in development of high capacity Li-ion batteries. Failure mechanisms of silicon electrodes are investigated at different material length scales and effective strategies are proposed to overcome them, which will benefit in developing high performance next-generation rechargeable Li-ion batteries.
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Mullaliu, Angelo <1991>. "Synthesis and Characterization of Prussian Blue Analogue Materials for Li-ion and post-Li Batteries". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8776/1/PhD_thesis.pdf.
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The global challenge responding to the need of efficient electrical energy storage is answered by rechargeable batteries, which are based on high-rate intercalation reaction of lithium ions into nano- and microstructured porous materials. A class of insetion-type materials is represented by Prussian blue analogues (PBAs), characterized by porous open 3D-frameworks which allow for a facile insertion/ extraction of ions with negligible lattice strain. In the present work we focused on the synthesis and characterization of PBAs in Li-ion and post-Li battery systems, their redox activity, electronic and structural reversibility while cycling. All synthesized materials exhibit good structural stability and negligible lattice strain during (de)insertion of ions and redox processes ascribable to one or more redox species. For instance, copper hexacyanoferrate features two redox sites, copper and iron, contrarily to what reported in the literature, while copper nitroprusside has been demonstrated to possess three redox centres, including the two metals, as well as the non innocent nitrosyl ligand as third site. Electrosynthesized copper hexacyanoferrate results extremely versatile towards a wide selection of ions in aqueous solution, ranging from monovalent to multivalent ions, while titanium hexacyanoferrate may reach a capacity equal to 55 mAh/g in potassium nitrate aqueous solution. This led to the conclusion that a H2O-based system would be feasible for the studied materials, and more in general for this class of compounds. Although they do not feature high specific capacities, they are characterized by good cycling ability and efficiency, as well as ion-versatility which can be favorable to a post-lithium strategy. The investigation of their reaction mechanism has led to the deep understanding of limiting steps, whereby it is possible to tailor new promising materials that could result competitive in the next future.
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Narayan, Anand. "State and Parametric Estimation of Li-Ion Batteries in Electrified Vehicles". Thesis, KTH, Elkraftteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-217124.
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The increasing demand for electric vehicles (EVs) has led to technological advancementsin the field of battery technology. State of charge (SOC) estimation is a vital function ofthe battery management system - the heart of EVs, and Kalman filtering is a commonmethod for SOC estimation. Due to the non uniformities in tuning and testing scenarios,quantifying performance of SOC estimation algorithms is difficult. Gathering data fordifferent operational scenarios is also cumbersome. In this thesis, SOC estimation algorithmsare developed and tested for a variety of scenarios like varying sensor noise andbias properties, varying state and parameter initializations as well as different initial celltemperatures. A validated and open-source simulation plant model is used to enable easygathering of data for different operational scenarios.The simulation results show that unscented Kalman filter performs better than extendedKalman filter in presence of hard nonlinearities and high initial uncertainties. However,both filters gave similar performance under nominal conditions implying that the choiceof estimation algorithms must depend on operational scenarios. Observability analysisalso gave valuable information to aid in selection of algorithms. The simulation plantmodel facilitated easy data collection for initial development of algorithms, which werethen tested successfully using a real dataset. Further testing using real datasets is requiredto enhance validation.Den ¨okande efterfr°agan p°a elfordon har lett till teknologiska framsteg inom omr°adet batteriteknik.Estimering av batteriets laddningstillst°and ¨ar en essentiell funktion i batteristyrsystemet,hj¨artat i ett elfordon, och g¨ors ofta genom att till¨ampa metoden Kalmanfiltrering.P°a grund av varierande implementations och testmetodik i litteraturen ¨ar detsv°art att kvantifiera estimeringsalgoritmer. I denna avhandling utvecklas algoritmer f¨oratt estimera ett batteris laddningstillst°and. Algoritmerna testas f¨or olika former av sensorfeloch initialtillst°and, samt f¨or en rad olika temperaturer. En validerad datormodell avbatteri, sensorer och omgivning nyttjas f¨or att generera representativa data f¨or de olikaf¨orh°allandena.Simuleringsresultat visar att den s°a kallade doftl¨osa varianten av Kalmanfiltret (UKF)presterade b¨attre ¨an det utvidgade Kalmanfiltret (EKF) i fall d¨ar systembeteendet ¨ar mycketolinj¨art och d°a initialtillst°andet ¨ar os¨akert. Under normala f¨orh°allanden presterardock de b°ada algoritmerna likv¨ardigt, vilket antyder att valet av algoritm b¨or g¨oras medavseende anv¨andningsscenario. En observerbarhetsanalys av de olika filtervarianterna gavytterligare v¨ardefull information f¨or valet av algoritm. Efter utveckling av filtreringsalgoritmernai simuleringsmilj¨o utf¨ordes tester p°a faktiska m¨atdata med goda resultat. F¨or attfullst¨andig validering av algoritmerna kr¨avs emellertid mer utt¨ommande tester.
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Chen, Chunhui. "Advanced Electrode Materials by Electrostatic Spray Deposition for Li-ion Batteries". FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2532.
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Recent development in portable electronics and electric vehicles have increased the demand for high performance lithium ion batteries. However, it is still challenging to produce high energy and high power lithium ion batteries. The major objective of this research is to fabricate advanced electrode materials with enhanced power density and energy density. Porous Li4Ti5O12 (LTO) and its nanocomposites (with Si and reduced graphene oxide (rGO)) synthesized by electrostatic spray deposition (ESD) technique were mainly studied and promising electrochemical performance was achieved. In chapter 3, porous LTO thin film electrode was synthesized by ESD to solve the low energy density and low power density issues by providing good ionic and electronic conductivities. Electrochemical test results showed that it had a large specific capacity of 357 mAh g-1 at 0.15 A g-1, which was even higher than its theoretical capacity. It also exhibited very high rate capability of 98 mAh g-1 at 6 A g-1. The improved electrochemical performance was due to the advantage of ESD generated porous structures. In order to further enhance the power density of LTO, ESD derived LTO/rGO composite electrodes were studied in chapter 4. In chapter 5, high energy density component Si was introduced viii into LTO composite. The synergistic effect between commercial LTO and Si powder was studied. Then, ESD derived LTO/Si/rGO composite was prepared and evaluated. At 0.15 A g-1, a stable capacity of 624 mAh g-1 was observed, which was much higher than the capacities of LTO and LTO/rGO electrodes. In addition, effect of activation process on electrochemical performance of carbon nanofibers (ACNFs) and feasibility of ion intercalation into 2D MMT montmorillonite clay (MMT) were studied and discussed in chapter 6. In summary, we have successfully synthesized various LTO based electrodes by ESD. Both high energy and high power density were achieved as compared to commercial LTO electrode. Through electrochemical characterization and charge storage distribution analysis, origins of the high rate capability were proposed. This work demonstrates ESD as a powerful tool for fabricating high performance porous structures and nanocomposite electrode materials.
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Hekselman, Aleksandra K. "Crystalline polymer and 3D ceramic-polymer electrolytes for Li-ion batteries". Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/11950.
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The research work presented in this thesis comprises a detailed investigation of conductivity mechanism in crystalline polymer electrolytes and development of a new class of ceramic-polymer composite electrolytes for Li-ion batteries. Firstly, a robust methodology for the synthesis of monodispersed poly(ethylene oxides) has been established and a series of dimethyl-protected homologues with 13, 15, 17, 28, 29, 30 ethylene oxide repeat units was prepared. The approach is based on reiterative cycles of chain extension and deprotection, followed by end-capping of the oligomeric chain ends with methyl groups. The poly(ethylene oxide) homologues show a superior level of monodispersity to previous work and were subsequently used to prepare crystalline PEO6:LiPF6 polymer electrolytes. A correlation between the number of ether oxygens in the polymer chain and the ionic conductivity of crystalline polymer electrolytes has been established. The structure and dynamics of the monodispersed complexes were studied using solid-state NMR spectroscopy for the first time. The results are in agreement with the proposed mechanism of ionic conductivity in crystalline polymer electrolytes. A new class of composite solid electrolytes for all-solid-state batteries with a lithium metal anode is reported. The composite material consists of a 3D interpenetrating network of a ceramic electrolyte, Li₁.₄Al₀.₄Ge₁.₆(PO₄)₃, and an inert polymer (polypropylene), providing continuous pathways for the ionic transport and excellent mechanical properties. 3D connectivity of this novel composite was confirmed using X-ray microtomography and AC impedance spectroscopy.
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Buiel, Edward. "Lithium insertion in hard carbon anode materials for Li-ion batteries". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0013/NQ36573.pdf.
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Si, Wenping. "Designing Electrochemical Energy Storage Microdevices: Li-Ion Batteries and Flexible Supercapacitors". Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-160049.
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Die Menschheit steht vor der großen Herausforderung der Energieversorgung des 21. Jahrhundert. Nirgendwo ist diese noch dringlicher geworden als im Bereich der Energiespeicherung und Umwandlung. Konventionelle Energie kommt hauptsächlich aus fossilen Brennstoffen, die auf der Erde nur begrenzt vorhanden sind, und hat zu einer starken Belastung der Umwelt geführt. Zusätzlich nimmt der Energieverbrauch weiter zu, insbesondere durch die rasante Verbreitung von Fahrzeugen und verschiedener Kundenelektronik wie PCs und Mobiltelefone. Alternative Energiequellen sollten vor einer Energiekrise entwickelt werden. Die Gewinnung erneuerbarer Energie aus Sonne und Wind sind auf jeden Fall sehr wichtig, aber diese Energien sind oft nicht gleichmäßig und andauernd vorhanden. Energiespeichervorrichtungen sind daher von großer Bedeutung, weil sie für eine Stabilisierung der umgewandelten Energie sorgen. Darüber hinaus ist es eine enttäuschende Tatsache, dass der Akku eines Smartphones jeglichen Herstellers heute gerade einen Tag lang ausreicht, und die Nutzer einen zusätzlichen Akku zur Hand haben müssen. Die tragbare Elektronik benötigt dringend Hochleistungsenergiespeicher mit höherer Energiedichte. Der erste Teil der vorliegenden Arbeit beinhaltet Lithium-Ionen-Batterien unter Verwendung von einzelnen aufgerollten Siliziumstrukturen als Anoden, die durch nanotechnologische Methoden hergestellt werden. Eine Lab-on-Chip-Plattform wird für die Untersuchung der elektrochemischen Kinetik, der elektrischen Eigenschaften und die von dem Lithium verursachten strukturellen Veränderungen von einzelnen Siliziumrohrchen als Anoden in einer Lithium-Ionen-Batterie vorgestellt. In dem zweiten Teil wird ein neues Design und die Herstellung von flexiblen on-Chip, Festkörper Mikrosuperkondensatoren auf Basis von MnOx/Au-Multischichten vorgestellt, die mit aktueller Mikroelektronik kompatibel sind. Der Mikrosuperkondensator erzielt eine maximale Energiedichte von 1,75 mW h cm-3 und eine maximale Leistungsdichte von 3,44 W cm-3. Weiterhin wird ein flexibler und faserartig verwebter Superkondensator mit einem Cu-Draht als Substrat vorgestellt. Diese Dissertation wurde im Rahmen des Forschungsprojekts GRK 1215 "Rolled-up Nanotechnologie für on-Chip Energiespeicherung" 2010-2013, finanziell unterstützt von der International Research Training Group (IRTG), und dem PAKT Projekt "Elektrochemische Energiespeicherung in autonomen Systemen, no. 49004401" 2013-2014, angefertigt. Das Ziel der Projekte war die Entwicklung von fortschrittlichen Energiespeichermaterialien für die nächste Generation von Akkus und von flexiblen Superkondensatoren, um das Problem der Energiespeicherung zu addressieren. Hier bedanke ich mich sehr, dass IRTG mir die Möglichkeit angebotet hat, die Forschung in Deutschland stattzufindenHuman beings are facing the grand energy challenge in the 21st century. Nowhere has this become more urgent than in the area of energy storage and conversion. Conventional energy is based on fossil fuels which are limited on the earth, and has caused extensive environmental pollutions. Additionally, the consumptions of energy are still increasing, especially with the rapid proliferation of vehicles and various consumer electronics like PCs and cell phones. We cannot rely on the earth’s limited legacy forever. Alternative energy resources should be developed before an energy crisis. The developments of renewable conversion energy from solar and wind are very important but these energies are often not even and continuous. Therefore, energy storage devices are of significant importance since they are the one stabilizing the converted energy. In addition, it is a disappointing fact that nowadays a smart phone, no matter of which brand, runs out of power in one day, and users have to carry an extra mobile power pack. Portable electronics demands urgently high-performance energy storage devices with higher energy density. The first part of this work involves lithium-ion micro-batteries utilizing single silicon rolled-up tubes as anodes, which are fabricated by the rolled-up nanotechnology approach. A lab-on-chip electrochemical device platform is presented for probing the electrochemical kinetics, electrical properties and lithium-driven structural changes of a single silicon rolled-up tube as an anode in lithium ion batteries. The second part introduces the new design and fabrication of on chip, all solid-state and flexible micro-supercapacitors based on MnOx/Au multilayers, which are compatible with current microelectronics. The micro-supercapacitor exhibits a maximum energy density of 1.75 mW h cm-3 and a maximum power density of 3.44 W cm-3. Furthermore, a flexible and weavable fiber-like supercapacitor is also demonstrated using Cu wire as substrate. This dissertation was written based on the research project supported by the International Research Training Group (IRTG) GRK 1215 "Rolled-up nanotech for on-chip energy storage" from the year 2010 to 2013 and PAKT project "Electrochemical energy storage in autonomous systems, no. 49004401" from 2013 to 2014. The aim of the projects was to design advanced energy storage materials for next-generation rechargeable batteries and flexible supercapacitors in order to address the energy issue. Here, I am deeply indebted to IRTG for giving me an opportunity to carry out the research project in Germany. September 2014, IFW Dresden, Germany Wenping Si
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Gao, Yifan. "Chemo-mechanics of alloy-based electrode materials for Li-ion batteries". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49027.
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Lithium alloys with metallic or semi-metallic elements are attractive candidate materials for the next-generation rechargeable Li-ion battery anodes, thanks to their large specific and volumetric capacities. The key challenge, however, has been the large volume changes, and the associated stress buildup and failure during cycling. The chemo-mechanics of alloy-based electrode materials entail interactions among diffusion, chemical reactions, plastic flow, and material property evolutions.
In this study, a continuum theory of two-way coupling between diffusion and deformation is formulated and numerically implemented. Analyses based on this framework reveal three major conclusions. First, the stress-to-diffusion coupling in Li/Si is much stronger than what has been known in other electrode materials. Practically, since the beneficial effect of stress-enhanced diffusion is more pronounced at intermediate or higher concentrations, lower charging rates should be used during the initial stages of charging. Second, when plastic deformation and lithiation-induced softening take place, the effect of stress-enhanced diffusion is neutralized. Because the mechanical driving forces tend to retard diffusion when constraints are strong, even in terms of operational charging rate alone, Li/Si nano-particles are superior to Li/Si thin films or bulk materials. Third, the diffusion of the host atoms can lead to significant stress relaxation even when the stress levels are below the yield threshold of the material, a beneficial effect that can be leveraged to reduce stresses because the host diffusivity in Li/Si can be non-negligible at higher Li concentrations.
A theory of coupled chemo-mechanical fracture driving forces is formulated in order to capture the effect of deformation-diffusion coupling and lithiation-induced softening on fracture. It is shown that under tensile loading, Li accumulates in front of crack tips, leading to an anti-shielding effect on the energy release rate. For a pre-cracked Li/Si thin-film electrode, it is found that the driving force for fracture is significantly lower when the electrode is operated at higher Li concentrations -- a result of more effective stress relaxation via global yielding. The results indicate that operation at higher concentrations is an effective means to minimize failure of thin-film Li/Si alloy electrodes.
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Ruiz, Onofre Patricia Nathaly. "Evaluation of pyrochemistry in molten salts for recycling Li-ion batteries". Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS346.
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Pour pallier la demande croissante de batteries Li-ion, il existe aujourd’hui le besoin urgent de recycler les composants de ces dispositifs. Recycler les matériaux cathodes qui contiennent des oxydes des métaux de transition est stratégique. Ces trois dernières années les recherches dans ce domaine ont augmenté de manière très significative. Dans le contexte du recyclage des batteries, il existe actuellement deux méthodes utilisées dans l’industrie : l’hydrométallurgie et la pyrométallurgie. L’objectif de ce projet a été de proposer une méthode alternative permettant de recycler les composants organiques et inorganique, en utilisant des mélanges de sels fondus comme milieu réactionnel. Les carbonates et chlorures fondus ont été choisis comme solvants pour leur efficacité dans le traitement des déchets. Le cobalt est un des matériaux critiques dans les batteries, rare sur la planète et toxique. Dans ce projet, nous avons étudié la dissolution et récupération du cobalt dans les carbonates et chlorures fondus. Des techniques électrochimiques (voltammetrie cyclique, chronoampérométrie) et la spectroscopie des rayons X ont été utilisés pour mener les investigations. Les résultats montrent une lente et faible dissolution du cobalt dans les carbonates fondus et il est présent sous la forme de Co (II). Les chlorures fondus ont été choisi comme deuxième alternative de solvant. La dissolution du cobalt et sa récupération ont été réussis dans ce milieu en ajoutant des additifsTo meet the increasing demands of lithium-ion batteries, there is an urgent need to recycle the batteries components. In particular, electrode materials containing transition metal oxides such as LiCoO2, LiNi1/3Mn1/3Co1/3O2, and LiNi0.8Co0.15Al0.05O2 are of strategic importance. Over the last three years, this field research has rocketed. In the frame of batteries recycling, there are two main methods that are used in industry nowadays: hydrometallurgy and pyrometallurgy. The aim of our research project is to propose an alternative method to recycle organic compounds and metals of electrode materials based on molten salts as reactive medium. Molten carbonates and molten chlorides have been chosen for their great efficiency on wastes treatment. Cobalt is one of the critical raw materials in batteries and it is rare on the Earth-crust and toxic for environment. In this work, we study cobalt dissolution and recovery in molten carbonates and chlorides. Electrochemical techniques (cyclic voltammetry, chronoamperometry) and X-Ray spectroscopy have been used for the investigations. Results show that a low and slow dissolution of cobalt is obtained in molten carbonates and in the form of Co (II). Molten chlorides have been used as a second alternative of solvent. Cobalt dissolution increase and its recovery have been achieved in this solvent when using additives
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Loaiza, Rodriguez Laura Cristina. "New negative electrode materials for Li-, Na- and K-ion batteries". Thesis, Amiens, 2019. http://www.theses.fr/2019AMIE0059.
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De nos jours, les batteries jouent un rôle clé dans presque toutes les technologies qui entourent le genre humain. Afin de répondre à la demande croissante, la conception d'appareils plus efficaces avec une densité d'énergie et une durée de vie plus élevées est cruciale. Dans ce contexte, le silicium et le germanium apparaissent comme des candidats prometteurs pour les matériaux d'électrodes en raison de leurs capacités théoriques élevées. Bien avant une mise en œuvre de ces matériaux au niveau industriel, plusieurs défis doivent être relevés. Les capacités élevées délivrées se font au détriment d'une expansion volumique lors de l'insertion des ions lithium par exemple. Ces changements de volume dans les particules de Si et de Ge entraînent la pulvérisation des particules, le détachement du collecteur de courant, la formation excessive et incontrôlée de la couche de SEI et une chute de la capacité. Différentes stratégies ont été rapportées dans la littérature pour surmonter les défis susmentionnés. Dans ce travail, deux approches ont été considérées, d'une part l'étude des alliages Si1-xGex et d'autre part l'étude de composés lamellaires. Dans le premier cas, la formation de la solution solide Si1-xGex améliore la rétention de capacité et la conductivité électronique. Dans le second, les matériaux lamellaires Siloxene et germanane, dérivés des phases de Zintl CaSi2 et CaGe2, amortissent les changements de volume et améliorent la cinétique du système. Une étude fondamentale des mécanismes électrochimiques a été réalisée pour comprendre les processus mis en jeu dans ces deux approchesNowadays, the batteries play a key role in almost all of the technologies that surround human kind. In order to satisfy the increasing demand, the design of more efficient devices with higher energy density and cycle life is crucial. In this context, silicon and germanium appear as promising candidates for electrode materials due to their high theoretical capacities. Although, prior to the implementation of these materials at an industrial level, several challenges must be addressed. The high delivered capacities come at the expense of a volume expansion and contraction upon alkali insertion and deinsertion. These volume changes in the Si and Ge particles, lead to particle pulverization, detachment from the current collector, excessive and uncontrolled formation of SEI layer and eventual capacity fade. Different strategies have been reported in the literature to overcome the aforementioned challenges. In this work, two approaches are considered, the study of the Si1-xGex alloys and the use of a layered morphology. In the first one, the formation of the Si1-xGex solid solution improves the capacity retention and the electronic conductivity. In the second one, the layered Siloxene and germanane, derived from the CaSi2 and CaGe2 Zintl phases buffers the volume changes and improves the kinetics of the system. On the other hand, the fundamental study of their electrochemical mechanism is crucial to understand the reasons behind an improvement and a failure. Thus, in this work we have studied the electrochemical lithiation mechanism of the Si- and Ge- based materials in an attempt to identify the different phases that are formed during cycling
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El, Khalifi Mohammed. "Étude théorique des matériaux d'électrode positive négative pour batteries Li-ion". Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20200.
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Ce mémoire est consacré à l'étude théorique des matériaux de cathode pour batteries Li-ion de structure olivine LiMPO4 (M=Mn, Fe, Co, Ni), des phases délithiées MPO4 et des phases mixtes LiFexMn1-xPO4, FexMn1-xPO4 et LiFexCo1-xPO4. La stabilité des phases magnétiques et les paramètres de maille théoriques ont été déterminés par la méthode des pseudopotentiels et comparés aux données expérimentales. Les structures électroniques ont été calculées par une méthode « tout électron » et analysées en termes d'hybridation des orbitales atomiques Ces résultats ont permis d'interpréter les spectres de photoélectrons X et d'absorption des rayons X, en particulier les modifications réversibles associées aux cycles de lithiation/délithiation. Les effets de la polarisation de spin et de la corrélation électronique ont été discutés. Enfin, le calcul des paramètres Mössbauer du 57Fe a montré qu'un accord quantitatif entre les résultats théoriques et les données expérimentales nécessitait la prise en compte de ces deux effets. Ce type de calcul a permis de prédire et d'expliquer que la transformation LiFePO4FePO4 s'accompagnait de la variation du gradient de champ électrique Vzz d'une extrémité à l'autre de l'échelle Mössbauer pour 57FeThis thesis is devoted to the theoretical study of the cathode materials for Li-ion batteries with olivine structure LiMPO4 (M=Mn, Fe, Co, Ni), the delithiated phases MPO4 and the mixed phases LiFexMn1-xPO4, FexMn1-xPO4 and LiFexCo1-xPO4. The magnetic phase stability and lattice parameters were theoretically determined from pseudopotential calculations and the results have been compared with experiments. Electronic structures were obtained from all electron calculations and analyzed in terms of orbital hybridization. The results have been used for the interpretation of X-ray photoemission and X-ray absorption spectra, especially changes due to lithiation/delithiation cycles. Effects of spin polarization and electronic correlation on the electronic structures have been also discussed. It has been shown that ab initio calculations of the 57Fe Mössbauer parameters also require these two effects in order to obtain a quantitative agreement with experiments. Finally, it was found that LiFePO4FePO4 transformation involves a dramatic change of the electric field gradient VZZ from one end to the other of the 57Fe Mössbauer scale
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Khatib, Rémi. "Les origines de l'hystérésis de potentiel dans les batteries Li-ion". Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20216/document.
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Dans les années 2000, les matériaux de conversion sont apparus comme une alternative intéressante aux matériaux d'insertion actuellement utilisés dans les batteries Li-ion. Ils réagissent avec le lithium pour former une électrode constituée de nanoparticules métalliques encapsulées dans une matrice lithiée. Pour comprendre ces réactions, le phosphure de cobalt (CoP) a été étudié au moyen de techniques théoriques et expérimentales. La complexité de ces systèmes nanocomposites n'a pas permis de caractériser toutes les espèces présentes dans l'électrode. Cependant, les calculs DFT ont prédit la formation de composés intermédiaires dont les potentiels de formation sont cohérents avec l'expérience. De plus, ces travaux ont mis en évidence l'importance de la réactivité de surface quant à l'origine de l'hystérésis de potentiel qui nuit au rendement énergétique de ce type d'électrode. La méthodologie développée spécialement pour les réactions de conversion, mais transférable vers d'autres réaction électrochimique, a été validée par les mesures expérimentalesIn the 2000s, conversion materials appeared as an interesting alternative to the insertion materials currently used in Li-ion batteries. They react with lithium to form an electrode constituted of metallic nanoparticles embedded into a lithiated matrix. To understand those reactions, cobalt phosphide (CoP) has been studied by theoretical and experimental techniques. The complexity of those nanocomposite systems does not allow to characterize all the species present inside the electrode. However, DFT calculations predicted the formation of intermediate compounds whose the formation potentials are in agreement with the experiment. Moreover, these studies have highlighted the importance of surface reactivity about the voltage hysteresis which harms to the electrode efficiency.The methodology especially developed for conversion reactions, but transferable to others electrochemical reaction, was validated by experimental measures
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Al, Nazer Rouba. "Système de mesure d'impédance électrique embarqué, application aux batteries Li-ion". Phd thesis, Université de Grenoble, 2014. http://tel.archives-ouvertes.fr/tel-00958783.
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La mesure d'impédance électrique en embarqué sur véhicule est un sujet clé pour améliorer les fonctions de diagnostic d'un pack batterie. On cherche en particulier à fournir ainsi des mesures supplémentaires à celles du courant pack et des tensions cellules, afin d'enrichir les indicateurs de vieillissement dans un premier temps, et d'état de santé et de charge dans un second temps. Une méthode classique de laboratoire pour obtenir des mesures d'impédance d'une batterie est la spectroscopie d'impédance électrochimique (ou EIS). Elle consiste à envoyer un signal sinusoïdal en courant (ou tension) de fréquence variable balayant une gamme de fréquences d'intérêt et mesurer ensuite la réponse en tension (ou courant) pour chaque fréquence. Une technique d'identification active basée sur l'utilisation des signaux large bande à motifs carrés est proposée. En particulier, des simulations ont permis de comparer les performances d'identification de différents signaux d'excitation fréquemment utilisés dans le domaine de l'identification et de vérifier les conditions correspondant à un comportement linéaire et invariant dans le temps de l'élément électrochimique. L'évaluation de la qualité d'estimation est effectuée en utilisant une grandeur spécifique : la cohérence. Cette grandeur statistique permet de déterminer un intervalle de confiance sur le module et la phase de l'impédance estimée. Elle permet de sélectionner la gamme de fréquence où la batterie respecte les hypothèses imposées par la méthode d'identification large bande. Afin de valider les résultats, une électronique de test a été conçue. Les résultats expérimentaux permettent de mettre en valeur l'intérêt de cette approche par motifs carrés. Un circuit de référence est utilisé afin d'évaluer les performances en métrologie des méthodes. L'étude expérimentale est ensuite poursuivie sur une batterie Li-ion soumise à un courant de polarisation et à différents états de charge. Des essais comparatifs avec l'EIS sont réalisés. Le cahier de charge établi à l'aide d'un simulateur de batterie Li-ion a permis d'évaluer les performances de la technique large bande proposée et de structurer son utilité pour l'estimation des états de vieillissement et de charge.
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Nazer, Rouba Al. "Système de mesure d'impédance électrique embarqué, application aux batteries Li-ion". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT007/document.
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La mesure d'impédance électrique en embarqué sur véhicule est un sujet clé pour améliorer les fonctions de diagnostic d'un pack batterie. On cherche en particulier à fournir ainsi des mesures supplémentaires à celles du courant pack et des tensions cellules, afin d'enrichir les indicateurs de vieillissement dans un premier temps, et d'état de santé et de charge dans un second temps. Une méthode classique de laboratoire pour obtenir des mesures d'impédance d'une batterie est la spectroscopie d'impédance électrochimique (ou EIS). Elle consiste à envoyer un signal sinusoïdal en courant (ou tension) de fréquence variable balayant une gamme de fréquences d'intérêt et mesurer ensuite la réponse en tension (ou courant) pour chaque fréquence. Une technique d'identification active basée sur l'utilisation des signaux large bande à motifs carrés est proposée. En particulier, des simulations ont permis de comparer les performances d'identification de différents signaux d'excitation fréquemment utilisés dans le domaine de l'identification et de vérifier les conditions correspondant à un comportement linéaire et invariant dans le temps de l'élément électrochimique. L'évaluation de la qualité d'estimation est effectuée en utilisant une grandeur spécifique : la cohérence. Cette grandeur statistique permet de déterminer un intervalle de confiance sur le module et la phase de l'impédance estimée. Elle permet de sélectionner la gamme de fréquence où la batterie respecte les hypothèses imposées par la méthode d'identification large bande. Afin de valider les résultats, une électronique de test a été conçue. Les résultats expérimentaux permettent de mettre en valeur l'intérêt de cette approche par motifs carrés. Un circuit de référence est utilisé afin d'évaluer les performances en métrologie des méthodes. L'étude expérimentale est ensuite poursuivie sur une batterie Li-ion soumise à un courant de polarisation et à différents états de charge. Des essais comparatifs avec l'EIS sont réalisés. Le cahier de charge établi à l'aide d'un simulateur de batterie Li-ion a permis d'évaluer les performances de la technique large bande proposée et de structurer son utilité pour l'estimation des états de vieillissement et de chargeEmbedded electrical impedance measurement is a key issue to enhance battery monitoring and diagnostic in a vehicle. It provides additional measures to those of the pack's current and cell's voltage to enrich the aging's indicators in a first time, and the battery states in a second time. A classical method for battery impedance measurements is the electrochemical impedance spectroscopy (EIS). At each frequency, a sinusoidal signal current (or voltage) of a variable frequency sweeping a range of frequencies of interest is at the input of the battery and the output is the measured voltage response (or current). An active identification technique based on the use of wideband signals composed of square patterns is proposed. Particularly, simulations were used to compare the performance of different excitation signals commonly used for system identification in several domains and to verify the linear and time invariant behavior for the electrochemical element. The evaluation of the estimation performance is performed using a specific quantity: the spectral coherence. This statistical value is used to give a confidence interval for the module and the phase of the estimated impedance. It allows the selection of the frequency range where the battery respects the assumptions imposed by the non-parametric identification method. To experimentally validate the previous results, an electronic test bench was designed. Experimental results are used to evaluate the wideband frequency impedance identification. A reference circuit is first used to evaluate the performance of the used methodology. Experimentations are then done on a Li–ion battery. Comparative tests with EIS are realized. The specifications are established using a simulator of Li-ion battery. They are used to evaluate the performance of the proposed wide band identification method and fix its usefulness for the battery states estimation: the state of charge and the state of health
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Mayo, Martin. "Ab initio anode materials discovery for Li- and Na-ion batteries". Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/270545.
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This thesis uses first principles techniques, mainly the ab initio random structure searching method (AIRSS), to study anode materials for lithium- and sodium- ion batteries (LIBs and NIBs, respectively). Initial work relates to a theoretical structure prediction study of the lithium and sodium phosphide systems in the context of phosphorus anodes as candidates for LIBs and NIBs. The work reveals new Li-P and Na-P phases, some of which can be used to better interpret previous experimental results. By combining AIRSS searches with a high-throughput screening search from structures in the Inorganic Crystal Structure Database (ICSD), regions in the phase diagram are correlated to different ionic motifs and NMR chemical shielding is predicted from first principles. An electronic structure analysis of the Li-P and Na-P compounds is performed and its implication on the anode performance is discussed. The study is concluded by exploring the addition of aluminium dopants to the Li-P compounds to improve the electronic conductivity of the system. The following work deals with a study of tin anodes for NIBs. The structure prediction study yields a variety of new phases; of particular interest is a new NaSn$_2$ phase predicted by AIRSS. This phase plays a crucial role in understanding the alloying mechanism of high-capacity tin anodes, work which was done in collaboration with experimental colleagues. Our predicted theoretical voltages give excellent agreement with the experimental electrochemical cycling curve. First principles molecular dynamics is used to propose an amorphous Na$_1$Sn$_1$ model which, in addition to the newly derived NaSn$_2$ phase, provides help in revealing the electrochemical processes. In the subsequent work, we study Li-Sn and Li-Sb intermetallics in the context of alloy anodes for LIBs. A rich phase diagram of Li-Sn is present, exhibiting a variety of new phases. The calculated voltages show excellent agreement with previously reported cycling measurements and a consistent structural evolution of Li-Sn phases as Li concentration increases is revealed. The study concluded by calculating NMR parameters on the hexagonal- and cubic-Li$_3$Sb phases which shed light on the interpretation of reported experimental data. We conclude with a structure prediction study of the pseudobinary Li-FeS$_2$ system, where FeS$_2$ is considered as a potential high-capacity electrochemical energy storage system. Our first principles calculations of intermediate structures help to elucidate the mechanism of charge storage observed by our experimental collaborators via $\textit{in operando}$ studies.
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DI, LUPO FRANCESCA. "Synthesis and characterization of nanostructured materials for Li-ion secondary batteries". Doctoral thesis, Politecnico di Torino, 2012. http://hdl.handle.net/11583/2496689.
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Rechargeable lithium batteries have already revolutionized the market of portable electronic devices. Potentially, in the next future, they are going to become the technology of choice for the huge market of electric vehicles (EV), hybrid-electric vehicles (HEV), and plug-in hybrid-electric vehicles (PHEV), where low cost, low environmental impact, as well as high specific performance batteries are needed.
Even so, intensive efforts are still under way to further improve this relatively young systems. Actually, for the next generation of rechargeable lithium-ion batteries, further breakthroughs, especially in modifying and improving already known materials, are essential.
In this context, considering the challenges and expectations for the energy storage devices in the near future, the present Ph. D. thesis offers an overview of the most promising electrode material for secondary Li-ion cells. Several materials were developed and thoroughly investigated, from the synthesis to the structural-morphological characterization and the evaluation of their electrochemical performance.
The introductory section of the thesis (chapters I to III) provides a brief survey of the necessary background in the field of Li-ion batteries and battery materials. Chapter IV focuses on the several characterization techniques and methods used to analyse the synthesized samples.
The following three chapters (chapters V to VII) focuses on negative electrodes. Three different kinds of materials were taken into account, each of them presenting a different reaction mechanisms towards lithium. To overcome the specific problems related to each material different synthesis approaches were considered and structural-morphological aspects were modified to optimise the final electrochemical performance.
The first material considered was titanium oxide (TiO2), able to intercalate lithium ions. TiO2 powder is employed in a wide range of application, thus a great number of publications are present in the literature on this subject. Aim of my work was to probe different syntheses and evaluate potential differences among them, both from structural-morphological and electrochemical point of view. Two different TiO2 polymorphs were synthesized by means of different synthesis strategies.
TiO2-B, usually considered the most promising polymorph, was firstly prepared. Although it showed appreciable characteristics, the performances of prepared samples were only modest, with respect to the following samples prepared. Nanostructured anatase, the second TiO2 polymorph considered, was successfully prepared by three different synthesis techniques: an evaporation-induced self-assembly (EISA) process, a sol-gel synthesis and a hydrolytic process. When the synthetic processes was optimized, the electrochemical performances of all these anatase samples were found to be superior with respect to the previous TiO2-B. Despite of the different synthesis methods adopted, the obtained results were similar: Coulombic efficiency, cyclability and specific capacity were highly valuable, also at the highest value of current regime applied, that is 10C (i.e. 3350 mA g−1). Some results are particularly interesting in view of a possible practical application. Actually they join good overall performances with a synthesis procedure extremely quick and easy to perform: this is greatly appreciable bearing in mind the increasing attention to low cost and environment friendly materials.
The second anode material considered was iron oxide (particularly, α-Fe2O3), that presents interesting features, such as abundance, low cost and environmental friendliness. Moreover, its theoretical specific capacity is extremely high, more than 1000 mAh g-1, compared to 370 mAh g-1 of graphite, the standard Li-ion battery anode. Its mechanism of reactivity towards lithium (conversion reaction) involves the formation and decomposition of Li2O, accompanying the reduction and oxidation of the metal. As these reactions are possible and reversible only if the material has nanometric dimensions/large interfacial surface, several nanostructured α-Fe2O3 samples were prepared by nanocasting strategy, using different kinds of mesoporous silica (i.e. SBA 15, MCM 41, MCM 48) as hard templates. The selected approach allowed to easily tune the characteristics of the final products. Indeed, opportunely selecting the template significant improvements in cycling stability were obtained. Another interesting path, that needs further in-depth examination, was the substitution of the traditional liquid electrolyte solution with a quasi-solid polymer electrolyte membrane. This new configuration demonstrated good cycling stability and capacity retention, directly related to the polymerization process used (i.e., UV photo-polymerisation) in which the polymeric network is directly formed in situ at the interface with the electrode film.
The last material considered for application as anode was tin oxide (SnO2), able to alloy with lithium and deliver the interesting reversible theoretical specific capacity value of 780 mAh g-1. As for α-Fe2O3, its main issue is the cycling stability after prolonged cycling and two different strategies have been explored in order to overcome this problem: particle nano-structuration and use of a carbonaceous buffer matrix. The first path allowed to obtain an interesting material, with very high specific capacity and good overall cycling efficiency. However, the problem of cyclability was only minimized but not completely solved. On the contrary, the second approach demonstrated to be completely successful, as the cyclability problem was completely solved and the obtained material showed elevated and stable electrochemical performances and was able to undergo prolonged galvanostatic discharge/charge cycles.
The last chapter of the thesis concerns on the development of a material for the positive electrode, that is lithium iron phosphate (LiFePO4). It has received great attention during the last years because of its low toxicity and low cost. Aim of my work was the optimisation of a previously developed synthetic route (i.e., mild hydrothermal process in the presence of an organic surfactant), in view of a possible practical application of the resulting material in commercial lithium-based batteries. The presence of the cationic surfactant CTAB confirmed to be a distinguishing feature of this synthesis. Actually, the most significant improvements were obtained modifying the physico-chemical properties of the CTAB water solution. In particular, the most significant results were obtained by the addition of a co-solvent during synthesis, which led to significant differences on the micellization process of the surfactant, thus resulting in marked differences on the structural-morphological characteristics and electrochemical performances of the resulting samples.
Two most evident effects were evidenced and both were related to the use of the co-solvent: the drastic change in morphology and the improved characteristics of the carbon layer. The changed morphology enhanced the ionic conductivity of the material, due to the promotion of the growth of the electrochemical active crystalline faces of LiFePO4. In addition, the improved characteristics of the carbon layer led to an increase of the final electronic conductivity of the active material particles, as the carbon layer surrounding the particles presented higher homogeneity and degree of graphitization.
When the choice of the reaction conditions was carefully controlled, the resulting material showed outstanding electrochemical results: the increased performance, particularly registered at extremely high discharge rates (even as high as 100C), led to the publication of an international patent in 2011. This confirmed the feasibility for this material to be commercially applied in several areas, the most important one being batteries conceived for automotive and transportation.
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Carra', A. "GAS MANAGEMENT AS POSSIBLE SOLUTION FOR LONG-LIFE LI-ION BATTERIES". Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/244685.
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This research work has been aimed at developing an innovative analytical methodology, useful to reveal gaseous side products within Li-ion cells. The analytical protocol is based on the coupling of infrared spectroscopy and electrochemical techniques.
Experiments have been carried out on Full Li-ion cell under resting and operative conditions. The time evolution of the most relevant gaseous product (CO2) has been monitored, revealing the conditions during which its generation is induced.
The analytical information have been used to project and develop a specific scavenger for CO2 adsorption. The scavenger has been configured in order to be complaint to battery requirements and its reliability has been proved, under battery condition, by the means of an absorption volumetric bench.
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Meunier, Valentin. "Unraveling Degradation Patterns in Li-ion Batteries through Electrochemical Analysis Procedures". Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS354.
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La chimie des électrodes positives dans les batteries Li-ion gravitent depuis ces vingt dernières années autour d’une famille d’oxydes lamellaire à base de nickel, manganèse et cobalt, aussi appelé phases NMC. La part belle étant faite à l’autonomie des batteries, les recherches visent à accroitre la densité énergétique de ces matériaux en augmentant leur fraction de nickel ainsi que leur tension de fonctionnement. Cependant, à des teneurs en nickel supérieure de 80% et tension de 4.2 V, les phases NMC sont sujettes à une série de dégradations physico-chimiques impliquant le matériau ainsi son interface avec électrolyte. Dégradations structurales, oxydation de l’électrolyte ou dissolution des métaux de transitions sont autant d’exemples illustrant la variété des mécanismes en jeu. Pire encore, les dégradations peuvent en déclencher d’autres et au final c’est toute la cellule qui se retrouve impactée, ce qui peut conduire à une chute brutale de la capacité de la batterie appelé « emballement ». Imprédictible et soudain, les emballements sont difficiles à expliquer avec les descripteurs classiques de performance comme la capacité en décharge (QD) ou l’efficacité coulombique. L’objectif de cette thèse est de développer des protocoles d’analyses combinant des techniques électrochimiques afin d’expliquer la chimie des dégradations en jeu, c’est-à-dire, le type de dégradation, leur localisation, et le tout, de façon quantitative. Ces techniques se basent principalement sur le glissement de capacités en fin de charge et décharge, ainsi que les dérivées dV/dQ et dQ/dV. Afin de mettre place ces techniques, le premier travail était de s’assurer de la qualité des mesures électrochimiques, grâce à la standardisation des méthodes d’assemblage et de test. Une fois les données répétables et de qualité, les protocoles ont permis d’étudier les effets de la dissolution du nickel sur l’électrode de graphite et de mettre en évidence des dégradations inattendues lors de l’utilisation d’un électrolyte super concentré, bien que reconnu pour sa haute stabilité. Les compostions d’électrolyte ont donc pu être adaptées afin de réduire les dégradations et augmenter la durée de vie de la batterie. En résumé, ces protocoles améliore la compréhension des dégradations et ainsi d’optimiser au mieux les conditions de fonctionnement des batteries Li-ion. Cela ouvre la voie vers la stabilisation interfaces et matériaux et le développement de nouvelles chimiesFor the past twenty years, the chemistry of positive electrodes in Li-ion batteries has predominantly focused on a group of layered oxides composed of nickel, manganese, and cobalt, commonly referred to as NMC phases. The primary goal of research has been to enhance the energy density of these materials by increasing their nickel content and operating voltage. However, once the nickel content surpasses 80% and the voltage reaches 4.2 V, the NMC phases become susceptible to a range of physicochemical degradations involving both the material itself and its interaction with the electrolyte. Structural degradation, electrolyte oxidation, and the dissolution of transition metals exemplify the various mechanisms at play. Furthermore, these deteriorations can trigger additional ones, ultimately affecting the entire battery cell and causing a sudden decline in battery capacity referred to as “rollover”. The unpredictable and abrupt nature of rollover poses challenges for conventional performance indicators like discharge capacity (QD) or coulombic efficiency in explaining them. The objective of this thesis is to develop analysis protocols that combine electrochemical techniques to comprehensively elucidate the chemistry underlying these deteriorations. This includes understanding the nature of the deterioration, its localization within the battery, and most importantly, quantifying its impact. These techniques primarily rely on observing the capacity slippages, as well as analyzing the derivatives dV/dQ and dQ/dV. To implement these techniques, the initial step involved ensuring the accuracy of the electrochemical measurements by standardizing the assembly and testing methods. Once reliable and high-quality data were obtained, the protocols facilitated the examination of the effects of nickel dissolution on the graphite electrode, revealing unforeseen deteriorations that occurred when using a highly concentrated electrolyte, despite its recognized high stability. Consequently, adjustments to the electrolyte compositions could be made to mitigate deteriorations and extend the battery's lifespan. In summary, these protocols significantly contribute to our understanding of deteriorations and enable the optimization of operating conditions for Li-ion batteries. This advancement allows for stabilizing interfaces and materials, as well as fostering the development of novel chemical approaches in battery technology