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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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Influence of glass fibers as negative electrode additives on properties of the lead accumulator
Cvaniga, Tomáš ; Zimáková, Jana (referee) ; Bača, Petr (advisor)
Main topic of bachelor project is studing effects of glass fibers as additives on the properties of the negative electrode lead-acid battery for hybrid electric vehicles. Purpose of bachelor work is to examine how to increase battery life due to glass fibers. In theoretical part of work is explained the activity of both types of lead-acid batteries, battery with flooded system and battery with hermetic system. There are processed other types of batteries. There is devoted space to the chemical process that take place during the battery operation. Accumulators operate in PSoC and there are explained some possible problems during the life of battery, which can lead to lose the charging ability. In this issue there are known concepts as PLC1, PLC2 and PLC3. There are processed some graphs in practical part, that show activity in the battery DoD mode, PSoC mode and formation process. There is an aim to study how the capacity changes after PSoC I and PSoC II mode.
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Influence of temperature on parameters of lithium-ion cells
Kuthan, Jiří ; Sedlaříková, Marie (referee) ; Máca, Josef (advisor)
Masters Thesis summarizes the theoretical findings about lithium-ion akumulators. It gives a overview of the basic types of galvanic cells, then deals in detail with the lithium-on cell. It's composition, electrochemical principle of working, thermal dependence, construction and area of application. The thesis describes the basic methods of measuring lithium-on cells, such as cyclic charging and discharging, cyclic voltammetry. The practical part compares selected types of materials for negative elektrodes in different temperatures.
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Monitoring of Electrode Changes of Negative Electrode for Lead-Acid Batteries by Operando Confocal Microscopy
Hálová, Hana ; Vanýsek, Petr (referee) ; Chladil, Ladislav (advisor)
The thesis is focused on the laser microscopy observation of the negative electrode for lead-acid batteries during their cycling. The surface changes are evaluated during both deep cycling and PSoC (Partial State of Charge) cycling. The mode leads to gradual degradation of the negative electrode – mostly because of irreversible sulfation. The speed of the sulfation can be influnced by additives of the negative active mass added already during production process. The active mass was firstly examined by electron microscope and X-ray diffractometer. The crystal growth during cycling was observed using confocal microscope Olympus Lext OLS4100.
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Study of materials for the Li-ion batteries by electron microscopy
Hujňák, Jan ; Čudek, Pavel (referee) ; Kazda, Tomáš (advisor)
This work deals with problems of lithium-ion batteries. In the theoretical part are described electrochemical sources in general and their division. The main representatives of individual types of electrochemical sources are described in more detail. In the next part the thesis focuses specifically on lithium-ion accumulators, their history, electrochemical reactions taking place inside and materials of individual parts of which the accumulator consists. Next part focuses on electron microscopy and its division into scanning and transmission. Basic parts and the principle of operation are described. The practical part is focused on creating a small cell for examination under an electron microscope.
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Composite electrode materials for lithium-ion batteries based on LiFePO4 prepared using GAC method
Vilhelm, Ondřej ; Neoral, Jiří (referee) ; Čech, Ondřej (advisor)
Presented work investigates the problem of secondary lithium-ion cells and the different available cathode materials. We have prepared samples of LiFePO4 with the addition of different kinds of carbon materials such as Super P, Vulcan and expanded graphite. We have always created the sample with and without surfactant. Developed samples were compared by measuring electrochemical methods (cyclic voltammetry, charge and discharge cycles and impedance spectroscopy). We also modeled the three-point cell for measuring electrochemical electrode materials.
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Negative Electrode for Lithium-Ion Batteries
Libich, Jiří ; Vanýsek, Petr (referee) ; Straková Fedorková, Andrea (referee) ; Vondrák, Jiří (advisor)
The dissertation thesis deals with investigation of electrode materials for Lithium-ion batteries. The main aim of investigation was focused to materials for negative electrode of Litihum-ion batteries. These negative electrode materials operate on intercalation principle. Object of interest are carbonaceous materials, especially their graphite forms. Graphite plays host role in lithium ion – graphite interactions that provides LiC6 compound. As a result of that investigation can be considered improving of graphite materials from stability, irreversible capacity and other parameters points of view. This kind of investigation takes an important part in field of elementary investigation work engaged to the next generation of Lithium-ion batteries. The work also describes the fire safety issue of Lithium-ion batteries along with compatibility of negative electrode materials and aprotic electrolytes.
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Negative Electrode for Sodium-ion batteries
Šimek, Antonín ; Jaššo, Kamil (referee) ; Libich, Jiří (advisor)
This bachelor thesis contains general introduction to the issue of batteries, their basic principles and distribution. It is mainly focused on the research of electrode materials for negative electrodes of sodium-ion batteries, which do not use lithium for their function. Thesis is also focused on lithium-ion batteries, because their development is closely linked to sodium-ion batteries. The practical part mainly contains the synthesis and characteristics of sodium metatitanate, which is used as active material in negative electrode mass.
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