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Deposited layers based on lead and cobalt for Li-ion batteries
Dorotík, David ; Libich, Jiří (referee) ; Máca, Josef (advisor)
The diploma thesis deals with the principles of operation of lithium ion batteries and their properties when using deposited thin films. The thesis is mainly focused on the formation of thin films using the electrolytic method and subsequently testing the properties of the thin film in an electrochemical cell. The test criteria are mainly the value of the capacity of the prepared electrode and the impact of cycling on the electrode layer itself, where the deposited layer is assessed before cycling and after cycling on an SEM microscope..
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Timekeeper for fire sport
Klimeš, Martin ; Šteffan, Pavel (referee) ; Levek, Vladimír (advisor)
The bachelor’s thesis to deals with the design of a time measuring device for a competition called fire sport. This timekeeper should be wireless and communicate in a sub-gigahertz spectrum. The first part of this work describes usable components. In the second part the thesis to deals with the design and itself realization.
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Lithium battery accumulation system testing
Straka, Jan ; Koval, Filip (referee) ; Morávek, Jan (advisor)
This bachelor thesis deals with properties, parameters and testing of lithium battery systems available on the market. It describes basic parameters of battery cells, which are used to make batteries and battery systems, equivalent electrical models of batteries for the purpose of conversion of their properties to an electrical circuit and stating and comparing commercial battery systems of different manufacturers. What follows is the introduction of tests to measure the parameters of battery systems. The experimental part of this thesis describes the used testing platform and evaluates results of carried out measurements.
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Nanofibrous Separators for Lithium-Ion Batteries
Pléha, David ; Míka, Martin (referee) ; Janderka,, Pavel (referee) ; Novák, Vítězslav (advisor)
Nanofibrous separators use in lithium-ion batteries brings many advantages. In contrast to contemporary used commercial separators, nanofibrous ones exhibit higher temperature resistance,ionic conductivity and higher electrolyte uptake. Better ionic conductivity is ensured by porous structure and large specific surface. Fibers creates channels for the ionic species motion. Amorphous texture of nanofibers allows quick lithium ionic species motion within the polymeric matrix of separator. Furthermore, these separators exhibit higher volume of uptaken electrolyte. Further advantage of electrospinned nanofibrous separators are both high porosity and chemical stability.
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Compatibility of negative electrode materials at system of lithium-ion battery
Šikuda, Milan ; Sedlaříková, Marie (referee) ; Libich, Jiří (advisor)
This thesis deals with a study of lithium-ion batteries. It is focused into negative electrode materials and electrolytes. In this thesis is presented synthesis, electrochemical properties, possibilities to improving negative electrode materials as LTO (Lithium Titanate Oxid) and graphite. These electrode materials were investigated with respect to their compatibility at electrolytes with carbonate solvents, Sulfolane and DMF (DiMethylFormamide) in detail. The main aim of this thesis is to characterize electrode materials and electrolyte properties depending on wide range of temperatures and their comparison for the purpose of achievement of the best solution. The thesis is divided into two main parts. The theoretical part of thesis describes composition, process of synthesis and analysis of lithium-ion cell. Practical part contains measuring and evaluating of charge-discharge and irreversible capacity characteristics related to variety of environmental temperatures.
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Effect of the pressure used in the manufacture of the electrodes on their final properties
Foltová, Anežka ; Tichý, Jiří (referee) ; Kazda, Tomáš (advisor)
The aim of this work is to describe final properties of the electrodes based on the amount of pressure used during its production. In the theoretical part of this work, secondary electrochemical accumulators are described, with the focus on Li-ion accumulators. In the main part of this work, the production of Li-ion accumulators, with usage of different pressures during its production is described. In the final part of this work, the examination of these created cells for the classification of the optimal production pressure is described.
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The electrical properties of modified ionic liquids
Kulhavý, Miloslav ; Libich, Jiří (referee) ; Máca, Josef (advisor)
This thesis deals with ionic liquids and use of ionic liquids as electrolytes in lithium-ion batteries. Thesis describes basic characteristics of secondary electrochemical cells and characteristics of ionic liquids. Thesis also describes modifications and measurement of ionic liquids. Thesis also presents the results of measurement conductivity and potential window of modified ionic liquids.
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Study of the influence of separator modification on the properties of Li-S batteries
Řehák, Petr ; Jaššo, Kamil (referee) ; Kazda, Tomáš (advisor)
This thesis deals with the development and current issues of Li-ion and Li-S accumulators, especially the separators. In the theoretical part is described history of Li-ion batteries, their properties and materials for the positive electrode. Li-S batteries and their problems are also described in this diploma thesis. In the practical part, electrochemical methods were described, and several separator samples with various modifications were created. These samples were then photographed using an SEM electron microscope and evaluated using electrochemical methods.
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