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Properties study of gel polymer electrolytes for lithium-ion batteries
Zítka, Jan ; Dvořák, Petr (referee) ; Musil, Michal (advisor)
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
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Gel polymer electrolytes with nanoparticles
Szotkowski, Radek ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
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.
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Gel polymer electrolytes modified by ionic liquids with aprotic solvents
Pospíšilová, Michaela ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
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.
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High temperature conductivity measurements of ceramic materials
Grochal, Peter ; Kazelle, Jiří (referee) ; Novák, Vítězslav (advisor)
The aim of this work is to get acquainted with the detailed structure of yttrium-stabilized zirconia, focusing mainly on conductivity. Coating platinum electrodes by screen printing. Solution of complexity of conductivity segregation by electrode geometry. Measurement of the conductivity of macroscopic samples of ceramics by impedance spectroscopy to determine the electrical behavior of the system. Creating equivalent circuits to measured data. Detect system behavior when excited by different AC voltage and electrode geometry values.
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Design of the new type of thermal atomic source for oxygen atoms
Šikula, Marek ; Bábor, Petr (referee) ; Mach, Jindřich (advisor)
Ultrathin oxid layers (especially high-k layers) are studied and fabricated by using atomic oxygen sources. These high-k ultrathin layers are integrated into CMOS transistors and DRAM capacitors. In this thesis theory of atomic oxygen beams and ways of theirs creation is summarized. On the basis of the obtained knowledge the engineering design of a unique type of the thermal atomic oxygen source is created. The design was tested by simple experiments. The 3D model and complete engineering drawings are included.
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Gel Polymer Electrolytes for Electrochemical Power Sources
Jahn, Michal ; Bartušek, Karel (referee) ; Paidar,, Martin (referee) ; Sedlaříková, Marie (advisor)
Dissertation thesis is focused on study of gel polymer electrolytes for electrochemical power sources, but also for other application. The electrical, electrochemical, mechanical and optical properties of gel electrolyte samples were measured in this work. The main goal was to prepare samples with high specific conductivity and with largest possible potential windows. Thermal stability of some samples was also monitored using thermogravimetric analyzes. The optimization of the chemical composition, quantities and ratios of individual chemicals has been made. Comparison of thermal polymerization and UV polymerization was performed. In the first part of the work, aprotic solvents and their mixtures in combination with lithium and sodium salts and one ammonium salt were investigated. Another subject of research was various crosslinking agents with methacrylate-based monomers. The second part of the work investigated the effect of ionic liquids, phosphor base flame retardants and nanoparticles as additives to gel electrolytes. In the last part of the work, the influence of the magnetic and electric field on the polymerization of gel electrolytes containing nanoparticles and selected copolymers was studied. Finally, a Li-ion cell with a graphite anode, LiFePO4 cathode and selected gel electrolyte was assembled.
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Electrochemical Properties Of Gel Polymer Electrolytes Modified Flame Retardants
Veselkova, Iuliia
This paper deals with preparation of gel polymer electrolytes modified by flame retardants based on methyl methacrylate. The aim of this work was to investigate the effect of thermal polymerization method on electrochemical properties such as ionic conductivity and potential window of gel polymer electrolytes. For measuring electrochemical properties, impedance spectroscopic techniques and linear voltammetry were used. Results indicate the dependence of ionic conductivity on the amount of flame retardant.
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High temperature conductivity measurements of ceramic materials
Grochal, Peter ; Kazelle, Jiří (referee) ; Novák, Vítězslav (advisor)
The aim of this work is to get acquainted with the detailed structure of yttrium-stabilized zirconia, focusing mainly on conductivity. Coating platinum electrodes by screen printing. Solution of complexity of conductivity segregation by electrode geometry. Measurement of the conductivity of macroscopic samples of ceramics by impedance spectroscopy to determine the electrical behavior of the system. Creating equivalent circuits to measured data. Detect system behavior when excited by different AC voltage and electrode geometry values.
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