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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Studium vlastností gelových polymerních elektrolytů pro lithno-iontové akumulátory / Properties study of gel polymer electrolytes for lithium-ion batteries

Zítka, Jan January 2013 (has links)
The present work deals with the research and development of gel polymer electrolytes and their applications. Thesis talks about the mechanisms that take place in gel electro-lytes. It also discusses the electroanalytical methods used in assessing the gel electro-lytes. The main focus of the work is the preparation of gel polymer electrolytes and compared their properties using methods of impedance spectroscopy, cyclic voltam-metry and methods of measurement of transference numbers. KEYWORDS
62

Anhydrous State Proton and Lithium Ion Conducting Solid Polymer Electrolytes Based on Sulfonated Bisphenol-A-Poly(Arylene Ethers)

Guha Thakurta, Soma 09 June 2009 (has links)
No description available.
63

A quest for better battery materials: Accelerating discovery through efficient exploration and rational design

Juan Carlos Verduzco Gastelum (16631382) 21 July 2023 (has links)
<p>The Materials Genome Initiative (MGI) has established guidelines to accelerate the discovery, development, and implementation of advanced materials in order to address current and future challenges. A key area of interest is the pressing need for more efficient energy storage systems to support technologies such as electric vehicles and renewable energies. In this work, we present an Integrated Computational Materials Engineering approach for the development of novel solid-state electrolyte materials. In particular, we embark on a quest to unravel the potential of ceramic garnet lithium lanthanum zirconium oxide (LLZO) for next-generation battery technologies.</p> <p>Our exploration begins with an overview of the current state of the Materials Innovation Infrastructure (MII) and our rationale behind choosing LLZO. Through the use of machine learning techniques and molecular dynamics simulations, we aim for efficient material optimization. Our findings are reinforced through experiments by using these materials as inorganic fillers in composite polymer electrolytes. Our findings demonstrate that the combined use of these complementary techniques facilitates the discovery of potential alternative solid-state electrolytes. Finally, we propose future research directions in materials science for the design of advanced materials using these integrated approaches. </p>
64

Gelové polymerní elektrolyty s nanočásticemi / Gel polymer electrolytes with nanoparticles

Szotkowski, Radek January 2017 (has links)
This master‘s thesis concerns gel polymer electrolytes formed on a methyl methacrylate base with selected types of nanoparticles. In the thesis are also analyzed the methods for measuring electrochemical properties. The practical portion deals with sample preparations of gel polymer electrolytes with different contents of alkaline salt in a solvent, creating gels with different nanoparticle content and comparing gel polymer electrolytes polymerized with heat and UV radiation. The thesis deals with the evaluation of these samples from the viewpoint of electrical conductivity and potential windows as well as thermal analysis of selected samples.
65

Gelové polymerní elektrolyty modifikované iontovými kapalinami s použitím aprotických rozpouštědel / Gel polymer electrolytes modified by ionic liquids with aprotic solvents

Pospíšilová, Michaela January 2018 (has links)
This graduate thesis is focused on measuring the electrical conductivity of the gel polymeric electrolytes, their preparation and deals with the changes of the performance ratio of the individual substances in gel electrolyte The theoretical part deals with electrochemistry, gel electrolytes, the conductivity of electrolytes, gel electrolytes preparation, methods used to evaluate the measured results and on the properties of the ionic liquids. In the practical part is summarized the process of preparing gel electrolytes, the chemicals to prepare the gels with ionic liquids. The results are evaluated by using impedance technique and linear voltammetry, there are calculated the values of the electrical conductivity of the electrolyte and potential windows.
66

Kladná elektroda na bázi MnOx pro PEMFC / MnOx based positeve electrode for PEMFC

Šmídek, Miroslav January 2011 (has links)
Construed bachelor work features into problems hydrogen fuel articles and survey on low-temperature fuell elements with polymeric electrolyte (PEMFC). Basic sight work is study feature catalyzers on base MnOx on real fuel cell type PEMFC. Exit are then measured characteristic this way creation fuel cell.
67

Étude de l’influence des solvants résiduels sur les électrolytes polymères pour batteries au lithium-ion

Mankovsky, Denis 08 1900 (has links)
Les batteries lithium-ion sont présentement d’excellentes candidates pour le stockage électrochimique d’énergie du futur. Cela dit, les batteries lithium-métal pourraient présenter des propriétés électrochimiques encore plus avantageuses. Cependant, ces types de batteries présentent encore des inconvénients, notamment au niveau de leur sécurité. Un des responsables majeurs de ceux-ci est l’électrolyte liquide organique. Parmi les différentes voies exploitables pour améliorer la sécurité de ces technologies, les électrolytes solides polymères (SPE) sont largement étudiés. Classiquement, ces systèmes sont mis en forme en présence de solvants qui sont ensuite évaporés. Aussi, lorsque le processus d’évaporation de solvants est terminé, les échantillons sont habituellement réexposés à l’air ambient. Or, d’une part, malgré le séchage important d’un échantillon, il se peut qu’il reste du solvant de mise en forme résiduelle. D’autre part, l’eau atmosphérique peut s’infiltrer au sein de celui-ci. Cependant, ce ne sont pas des facteurs qui sont considérés dans la recherche présente dans le domaine. Bien que l’influence des solvants résiduels est parfois mentionnée, elle n’est jamais quantifiée de façon convenable, et cela reste un facteur mal compris et souvent omis. Dans cette étude, des échantillons de différents types de SPE ont été préparés selon des conditions standards, leur teneur en solvants résiduels a été contrôlée et analysée par différentes méthodes développées au cours de cette recherche. Pour la quantification de l’eau, un analyseur d’humidité spécifique a été utilisé, et il a été montré que l’eau résiduelle permet d’augmenter les conductivités ioniques des échantillons. Pour la quantification des solvants résiduels organiques, une méthode analytique employant la chromatographie gazeuse couplée à la spectrométrie de masse a été développée. Il a été observé que comme avec l’eau, les solvants résiduels augmentent la conductivité ionique des échantillons étudiés. Cette étude doit montrer aux chercheurs dans le domaine que le contrôle des solvants résiduels est un facteur primordial dans le développement des SPEs, et que c’est un paramètre qui doit être systématiquement évalué. / Lithium-ion batteries are today’s candidates for future long-term electrochemical storage of renewable energies. That said, lithium-metal batteries could offer even more appealing electrochemical properties. However, both types of batteries still suffer from certain technical difficulties such as safety. One of the culprits for their reduced safety is the use of an organic liquid electrolyte. Indeed, the latter is flammable and poses a risk, as numerous battery fire accidents have shown throughout the past years. Luckily, scientific research has been able to propose safer alternatives to liquid electrolytes applicable to lithium batteries by replacing the former by solid state electrolytes. Amongst these systems, solid polymer electrolytes (SPE) can be considered as a promising possibility to eliminating the safety issues. Conventionally, SPEs are prepared in a solvent that is evaporated at the end of the manufacturing. Additionally, atmospheric humidity can infiltrate these materials and alter their properties. However, residual solvent content is seldom mentioned, and even when it is, the specific experimental parameters are lacking which makes it a misunderstood and regularly omitted factor in battery performance evaluation. In this study, residual solvents are quantified in different SPE systems that are prepared according to standard and non-standard procedures. To do so, certain samples have had their solvent content artificially modified in order to control and analyse it. Firstly, water content is assessed using a specific moisture analyser. Secondly, an analytical method employing gas chromatography coupled to mass spectrometry has been developed to determine the residual SPE processing solvent. It has been concluded that, similarly to water, residual solvents also contribute to enhancing ionic conductivities of SPEs. Hopefully, this study will shed light on the importance of controlling residual solvent content in SPEs, and the necessity of systematically assessing that parameter.

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