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Electrodes for lithium-ions batteries based on LiCoO2
Nejedlý, Libor ; Čech, Ondřej (referee) ; Sedlaříková, Marie (advisor)
This master´s thesis deals with electrodes for lithium-ions batteries based on LiCoO2. The first part of the project is devoted to the characteristics of Li-ion batteries, electrochemical reactions and characteristics of electrode materials. The next part describes an experiment that deals with the effects of NA doping on performance of layered materials for lithium secondary batteries. The materials were measured by cyclic voltammetry, impedance spectroscopy and galvanostatic cycling.
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Porosity increasing agents for supercapacitors
Hovorka, Martin ; Dvořák, Petr (referee) ; Sedlaříková, Marie (advisor)
This work deals with questions connected with ultracapactors and lightening agents of activated carbon used for production of supercapacitors’s electrodes. Our goal was examination of ideal ratio of carbon and lightening agent in surveyed electrode. Materials which were used: expanded graphite, soda saleratus, ammonium bicarbonate and ammonium formate. Specimens were measured by cyclic voltammetry. The best results was reached by using of soda saleratus with ideal ratio 1:0,5. During measurement was found that weight of electrode has basic effect on eventual capacity.
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New polymer gel electrolytes
Cafourek, Martin ; Vondrák, Jiří (referee) ; Sedlaříková, Marie (advisor)
This work deals with preparation of gel polymer electrolytes with content of alcaline saults and with conductivity measurements. Materials used for polymer electrolyte preparation and methods of preparation are analysed with respect to usable properties. Experimental part is focused on preparation of methacrylate gel electrolytes, on basis of methacrylate and 3-(Trimehtoxysilyl)propyl methacrylate. Electric conductivity measured by means of impedance spectroscopy is evaluated and compared and possibilites for further research are proposed.
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Mechanical propertties gel polymer aprotic electrolytes
Bárta, Vladimír ; Musil, Michal (referee) ; Sedlaříková, Marie (advisor)
This work deals with the measurement of electrical conductivity and mechanical properties of gel polymer electrolyte containing Lithium ion and their preparation. The theoretical part deals with the development of gel polymer electrolyte, their use and methods of measurement of electrical conductivity and mechanical properties. In the experimental part describes the preparation of gel electrolyte, the measurement of electrical conductivity, temperature dependence and the measurement of mechanical properties.
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Properties of electrode materials for alcaline accumulators
Fusek, Petr ; Vrbický, Jiří (referee) ; Sedlaříková, Marie (advisor)
The Bachelor´s Thesis is aimed at the problematic of the binders, that effects the features of the positive electrode of alcalic accumulators. The additive used on nickel´s electrode was cobalt. In the practical part of this thesis there is described a process for etching the nickel electrode and the following electrodepositions applied on these electrodes. Measurements of different concentrations of nickel and cobalt were examined and analysed in the graphs which are part of this thesis. There have been made comments of these graphs and the conclusions and observations as well.
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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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Design of Perovskite Photovoltaic Solar Cells and Research of their Stability
Strachala, Dávid ; Šály,, Vladimír (referee) ; Sedlaříková, Marie (referee) ; Vaněk, Jiří (advisor)
The work in the first part describe the design of a perovskite photovoltaic cell with planar inverse structure using photovoltaically active material CH3NH3PbI3 and CH3NH3PbI3-xClx. The theoretical description of perovskite materials is supplemented by knowledge of degradation mechanisms reducing the resulting stability of samples and also presents a comprehensive overview of the technology development. The following text brings an innovative process for the perovskite photovoltaic cells production, which has enabled manufacturing of reproducible samples with parameters comparable to the foreign workplaces. The second part of the research analyzes the influence of the external environment to the samples and based on experimental outputs explains possible degradation mechanisms of perovskite material. At the final part of the dissertation thesis is presented and characterized unique structure of planar inversion perovskite cells with a material composition increasing the resistance against external humidity.
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Thin film systems
Rada, Vojtěch ; Sedlaříková, Marie (referee) ; Zatloukal, Miroslav (advisor)
This bachelor’s thesis is focused on the problematics of thin-film technology. In the beginning the work deals with a general theory of this problematics, discusses various methods and ways to lay a thin film, where more emphasis is placed on magnetron sputtering, which is used in the practical part of the work, and describes procedures that are performed before and after the application of the thin film. The magnetron sputtering coating machine NP-12 and its control are described in the practical part of the work. Subsequently the selection and adjustment of suitable substrates is made, the thin-film system is deposited using the magnetron sputtering method and the analysis of the properties of deposited thin-film samples is done.
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Biodegradable bones implants based on iron
Hrabovský, Jan ; Zatloukal, Miroslav (referee) ; Sedlaříková, Marie (advisor)
This work deals with a current topic, which are biodegradable bone implants. These implants seem to be a suitable candidate for temporary fixations, with their gradual decomposition. An important parameter is not only the mechanical properties so that the material can withstand the load, but above all the corrosion properties and the degradation process. This work introduces the physiology of bone, trace elements and also describes current trends in the field of implants. The last part is a theoretical introduction to cross-stage processes. The practical part is focused on the preparation of iron-based samples with various dopants, subsequent annealing and analysis.
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