Este trabalho apresenta a preparação de filmes nanoestruturados de óxido de manganês e de vanádio por diferentes técnicas e a sua caracterização eletroquímica utilizando diferentes líquidos iônicos como eletrólito. Os filmes de óxido de manganês foram preparados por automontagem camada-por-camada e por eletrodeposição assistida por molde de nanoesferas de poliestireno. Os filmes de óxido de vanádio foram preparados também por automontagem camada-por-camada e por deposição eletroforética. Diversos aspectos relacionados ao uso dos líquidos iônicos como eletrólitos foram discutidos: os resultados obtidos para os filmes de óxido de manganês por automontagem camada-por-camada mostraram que os íons do líquido iônico participam do processo de compensação de carga superficialmente e que o cátion do líquido iônico, apesar de mais volumoso, apresenta coeficiente de difusão maior que o Li+, formando uma barreira à intercalação dos mesmos na estrutura do material. A partir dos resultados obtidos para os filmes de óxido de manganês por eletrodeposição assistida por nanoesferas de poliestireno, foi possível verificar que o desempenho do sistema depende da natureza do líquido iônico utilizado, sendo possível obter desempenho superior aos solventes orgânicos convencionais com um dos líquidos iônicos utilizados do ponto de vista da ciclabilidade. Desempenho superior aos eletrólitos convencionais também foi observado para os filmes de óxido de vanádio obtidos por automontagem camada-por-camada. Por fim, a caracterização eletroquímica em líquidos iônicos dos filmes de óxido de vanádio obtidos por deposição eletroforética mostrou que não apenas o uso de nanopartículas, mas também o modo de deposição das mesmas influencia no desempenho eletroquímico do sistema. De maneira geral, os resultados obtidos mostraram que o uso de filmes nanoestruturados e de líquidos iônicos como eletrólitos constituem alternativas promissoras para a obtenção de dispositivos de armazenamento e conversão de energia de alto desempenho e segurança. / This work presents the preparation of manganese and vanadium oxides nanostructured films by different techniques and their electrochemical characterization in different ionic liquids based electrolytes. Manganese oxide films have been prepared by self-assembly layer-by-layer and by electrodeposition assisted by polystyrene nanospheres template. Vanadium oxide films have been also prepared by self-assembly layer-by-layer deposition and by electrophoretic deposition. Several aspects related with the use of ionic liquids as electrolytes have been discussed: the obtained results from layer-by-layer deposition of manganese oxide have shown that ionic liquid ions also participate in the charge compensation process, but only superficially; in spite of ionic liquid cation been larger than Li+, it moves faster, achieving the electrode surface before, being a barrier for Li+ intercalation. From the results obtained for the manganese oxide prepared by template assisted electrodeposition, it was possible to notice that electrochemical performance is dependent on the ionic liquid structure, being possible to achieve higher performance than with conventional organic solvent electrolyte with one of the studied ionic liquid. Superior performance in comparison with conventional electrolyte has also been achieved for vanadium oxide films prepared by layer-by-layer deposition from the point of view of cyclability. Finally, the electrochemical characterization of vanadium oxide films prepared by electrophoretic deposition in ionic liquids has shown that not only the use of nanoparticles but also the deposition method employed influences the electrochemical performance. To conclude, the obtained results have shown that the use of nanostructured films and ionic liquids as electrolytes are promising alternatives for the obtention of high performance energy storage and conversion devices.

This thesis is focused on the design of remote data transmission equipment, without access to mains power. The device will measure the voltage of the gas pipeline and send this information to the operator for processing. Analysis of today's technologies for long-distance transmission and based on the selected technology, the device will be designed. According to selected components, its power supply will be designed with the aim of long-term functionality and continuous operation.

Des études antérieures ont montré que l'incorporation de groupements méthyles par dépôt assisté par plasma (PECVD) dans des couches minces de silicium améliore leur cyclabilité lors de leur utilisation comme électrodes négatives pour les batteries Li-ion. Dans le cadre de cette thèse, plusieurs approches ont été adoptées pour mieux comprendre les phénomènes impliqués dans ce nouveau matériau lors de cyclages en condition réaliste.Nous avons montré que la spectroscopie infrarouge operando en géométrie de réflexions totales atténuées (ATR-FTIR) apporte des informations quantitatives sur les phénomènes mis en jeu lors de la lithiation et de la délithiation de la couche active. L'augmentation progressive de l'absorbance pendant la première lithiation permet notamment de suivre la formation d’une phase très riche en lithium LizSi qui envahit progressivement le matériau. Nous avons montré que la concentration z du lithium dans cette phase dépend de la teneur en groupements méthyles. Nous avons expliqué ce phénomène par deux effets distincts : (1) la fragilisation du matériau du fait de la diminution du degré de réticulation et de la cohésion. (2) la porosité qui augmente aux teneurs en méthyles plus élevées. Nous avons par ailleurs obtenu par microscopie électronique en transmission une mise en évidence directe de cette porosité à l’échelle nanométrique et de son accroissement avec la teneur en méthyle.Les mesures de spectrométrie de masse à ionisation secondaire à temps de vol (ToF-SIMS) en collaboration avec Chimie ParisTech ont montré que l’invasion du lithium à partir de la phase LizSi vers la zone non-lithiée est un phénomène très lent (correspondant à un coefficient de diffusion D ~10-19 cm2).Nous avons constaté par spectroscopie ATR-FTIR operando et mesures électrochimiques que l'évolution de la couche de passivation (SEI) dépend du taux du cyclage et de la teneur en groupements méthyles lors du premier cycle.Enfin, les phénomènes se produisant lors de l’interruption de la lithiation électrochimique ont été suivis à différents états de charge par spectroscopie ATR-FTIR operando et spectroscopie d'impédance électrochimique (EIS). Nous avons découvert qu'en début de lithiation, une partie du lithium inséré dans la couche repart vers l'électrolyte et contribue à l'augmentation de l'épaisseur de la SEI formée sur l'électrode. / Previous studies showed that the incorporation of methyl groups in silicon thin films obtained by Plasma Enhanced Chemical Vapor Deposition (PECVD) improves their stability as negative electrodes in Li-ion batteries. In this thesis, several approaches have been used to understand phenomena occurring in the so-called "methylated amorphous silicon" during realistic cycling condition.We have shown that infrared spectroscopy operando in attenuated total reflection geometry (ATR-FTIR) provides quantitative information on the phenomena involved during the lithiation and the delithiation of the active material. The gradual increase of the absorbance during the first lithiation makes it possible to follow the formation of a lithium-rich phase LizSi which gradually invades the material. We have shown that the concentration z of lithium in this phase depends on the content of methyl groups. This behavior has been explained by two distinct effects: (1) the weakening of the material due to the methyl-induced lowering of its reticulation degree and cohesion. (2) the increase of the material porosity at high enough methyl content. Transmission Electron Microscopy (TEM) measurements revealed that a porosity is present at the nanometer scale in the active material and increases with methyl content. Time-Of-Flight Secondary Ion Mass Spectroscopy measurements performed at Chimie ParisTech have shown that the lithium invasion of the pristine active material from the lithium-rich phase is an utterly slow phenomenon (corresponding to a diffusion coefficient D ~10-19 cm2).We observed Solid Electrolyte Interphase (SEI) evolution during first cycle depends on cycling rate and methyl content, using operando ATR-FTIR spectroscopy and electrochemical methods.The evolution of the material after interruption of the electrochemical lithiation at several states of charge has been monitored using operando ATR-FTIR spetroscopy and Electrochemical Impedance Spectroscopy (EIS). Those measurements show that part of the lithium initially inserted in the layer returns to the electrolyte during relaxation and contributes to the growth of the SEI.

No description available.

<p>Critical materials are crucial to the wide deployment of clean energy technologies and advanced technology such as electric vehicles (EVs), smartphones, high-efficiency lighting, and wind turbines. Particularly, rare earth elements (REEs) and lithium are key elements for clean energy and EVs. However, higher REEs and lithium demand for clean energy transformation, extreme supply reliance on certain area exports, and severe environmental issues during mining and processing cause uncertainty for future clean energy and transportation development. Our study aims to develop dynamic LCA with scenario analysis to simulate the future possible sustainability pathways for critical materials for stakeholders and apply life cycle assessment (LCA) to evaluate the latest REEs and lithium extraction and recycling technologies. Dynamic LCA (DLCA) integrates the temporal datasets to predict the future environmental impact of a product. The databases are mainly from Ecoinvent and Critical Materials Life Cycle Assessment Tool (CMLCAT). Python package Brightway2 and Temporalis are used to simulate the DLCA.</p> <p>The study of DLCA on the REEs industry reveals the future predictive REEs environmental impact trend, providing a clear policy strategy to reach sustainability goals for stakeholders. The results show that shifting REEs resources from China to Australia and increasing the recycling rate are key factors in reducing environmental impact in the future. Considering the degradation of rare earths ore and storage depletion in China, such as the decreased production of heavy REEs from Ion adsorption clay in southern China, exploration, and inclusion of potential REEs production projects will be the possible sustainable way in the following decade. </p> <p>LCA of RE recovery from room temperature ionic liquid (RTIL) electrochemical process helps us explore the benefits of recycling RE from the e-waste. Although RTIL contributes a higher impact on ozone depletion and global warming, close-loop recycling RTIL could reduce substantial environmental impact. Lithium recovery from geothermal brine provides the great source for fulfilling the domestic demand of the U.S. Compared to the conventional Li compounds production, this method is efficient and has 25-41% lower global warming potential. The government, researchers, and industry could benefit from this study for exploring advantage and drawback strategies for the future environmental footprint of NdFeB magnet production and identifying environmental hotspots of the latest recycling and extraction process of REEs and lithium.</p>

Recently in more or all electric vehicles, higher voltage batteries are used which employ large number of cells in series. Series connection among cells may lead to single point of failures, safety and charge equalization issues that demand complex control and costly and/or lossy battery management methods. Most present day high voltage batteries use dissipative-charge balancing methods, which result in poor efficiency, additional thermal management burden and lower overall vehicle range. Furthermore, the output voltages of such batteries remain unregulated and may widely change with load and environmental conditions, complicating the overall power pass design of the electrical power system. As a step forward to address these issues, this thesis studies a fault-tolerant regulated active high voltage electric accumulator with integrated power electronics for safe charge and discharge of the high voltage energy storage system. / Thesis / Master of Applied Science (MASc)

Магистерская диссертация посвящена синтезу и исследованию структуры положительного электродного материала на основе железофосфата лития. В работе проведена работа по поиску и систематизации информации по интересующей теме, описаны методики синтеза, изучению методом спектроскопии комбинационного рассеивания света и результаты измерения структуры, как железофосфата лития, так и композитов на его основе. Изучена зависимость спектра КРС от мощности лазерного излучения. Сделано предположение о модификации поверхностного слоя частиц железофосфата лития после воздействия лазерного излучения. / The master's thesis is devoted to the synthesis and study of the structure of the positive electrode material based on lithium iron phosphate. The work was carried out to search for and systematize information on a topic of interest, describes synthesis methods, studies of Raman spectroscopy and the results of measuring the structure of both lithium iron phosphate and composites based on it. The dependence of the Raman spectrum on the power of laser radiation was studied. An assumption was made about the modification of the surface layer of lithium iron phosphate particles after exposure to laser irradiation.

Ce travail consiste en l’étude par RMN multinoyaux de matériaux paramagnétiques d’électrodes positives pour batteries au Li. La RMN du solide permet une caractérisation de l’environnement local du noyau sondé grâce à l’exploitation des interactions hyperfines dues à la présence d’une certaine densité d’électrons célibataires (déplacement de contact de Fermi) ou de conduction (déplacement de Knight) sur ce noyau (densité transférée selon des mécanismes plus ou moins complexes). Les matériaux étudiés sont des phosphates de métaux de transition tels que Li3M2(PO4)3 (M = Fe, V), la famille des tavorites LiMPO4X (M = Fe, Mn; X = OH, F) ou encore les phases homéotypiques MPO4.H2O (M = Fe, Mn, V). Pour tous ces matériaux, caractérisés par RMN du 7Li, 31P et 1H, l’environnement local de ces noyaux a été étudié afin d’envisager les mécanismes de transfert de spin possibles. Des calculs ab initio ont été effectués pour reproduir les déplacements de RMN, puis établir des cartes de densité de spin afin d’étayer ou compléter la compréhension de ces mécanismes. / Paramagnetic materials for positive electrodes for Li batteries have been studied by multinuclear NMR. The local environment of the probed nucleus can be characterized by solid state NMR making use of hyperfine interactions due to transfer of some electron spin density (Fermi contact shift) on this nucleus, via more or less complex mechanisms. We studied a series of transition metal phosphates as Li3M2(PO4)3 (M = Fe, V) with anti-NASICON structure, LiMPO4X (M = Fe, Mn; X = OH, F) belonging to the tavorite family and the homeotypic phases MPO4.H2O (M = Fe, Mn, V). All these materials have been characterized by 7Li, 31P and 1H NMR, and the local environments of these nuclei have been analyzed to propose possible spin transfer mechanisms. First principles DFT calculations have been carried out to, first of all, reproduce the experimental NMR shifts, and then to confirm or complement the understanding of these mechanisms, in particular by plotting spin density maps.

Les polymères sont à l’heure actuelle étudiés dans de nombreux domaines comme la chimie, la biochimie, les nanotechnologies, l'électronique, la médecine ou encore les sciences des matériaux et trouvent des applications dans des domaines comme l’industrie automobile, la chimie fine. L’objectif de cette thèse est de réaliser la fonctionnalisation de polymères et de modifier les propriétés de ces matériaux afin d’envisager des nouvelles applications. Nous nous sommes intéressés à des polymères de la famille des poly(aryle éther) et plus particulièrement au poly(éther éther cétone) (PEEK). Ce polymère est connu pour ses propriétés mécaniques, thermiques, électriques ou encore pour sa résistance aux produits chimiques. Dans le premier chapitre, il est question de la fonctionnalisation des différents polymères de départ par des fonctions chlorures de sulfonyle, acides sulfoniques et sulfonamides. Le second chapitre est consacré à la synthèse et à l’étude électrochimique de nouveaux électrolytes polymériques et à de nouvelles membranes pour d’éventuelles applications dans le domaine des batteries au lithium et au sodium, ainsi que dans le domaine des piles à combustible. Dans un troisième chapitre, la préparation de nouveaux catalyseurs métalliques dérivés d’acides sulfoniques polymériques est discutée. Une étude de l’activité catalytique de ces différents catalyseurs a été réalisée sur la réaction d’acylation de Friedel-Crafts. Le quatrième chapitre est consacré à la préparation de nouveaux matériaux ayant des propriétés optiques intéressantes. Enfin dans un cinquième chapitre, la préparation et l’étude de nouveaux matériaux ayant des propriétés antibactériennes sont exposées. / Polymers are now being studied in many fields such as chemistry, biochemistry, nanotechnology, electronics, medicine or material science and have applications in areas such as automotive industry, food industry, fine chemistry. The objective of this thesis is to achieve the functionalization of polymers and modify the properties of these materials in order to consider new applications. We were interested in polymers with the poly(aryl ether) motif, more particularly poly(ether ether ketone) (PEEK). This polymer is known for its mechanical, thermal, electrical properties and for its resistance to chemicals. In the first chapter, we present the functionalization of different polymers by sulfonyl chloride, sulfonic acid and sulfonamide functions. The second chapter is devoted to the synthesis and electrochemical study of novel polymeric electrolytes and new membranes for potential applications in the field of lithium and sodium batteries, as well as in the field of fuel cells. In the third chapter, the preparation of new metal catalysts derived from polymeric sulfonic acids is discussed. A study of the catalytic activity of these different polymeric catalysts was carried out on the Friedel-Crafts acylation reaction. The fourth chapter is devoted to the preparation of new materials with interesting optical properties. Finally, in the fifth chapter, the preparation and the study of new materials with antibacterial properties are reported.

The diploma thesis is focused on the theoretical knowledge of lithium accumulators. More attention is given to electrolytes and especially to flame retardants, where the types and individual examples of flame retardants are described more detailed. The practical part is focused on the individual laboratory measurement of selected samples of electrolytes with different flame retardants. The measurement results are analyzed in other parts.