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Study of the electrode materials for Li-Ion accumulators by electron microscopy
Kaplenko, Oleksii ; Čudek, Pavel (referee) ; Kazda, Tomáš (advisor)
The aim of this work is to describe the influence of temperature on the structure and chemical composition of electrode materials for Li-ion accumulators. Theoretical part of this thesis contains described terminology and general issues of batteries and their division. Every kind of battery is provided with a closer description of a specific battery type. A separate chapter is dedicated to lithium cells, mainly Li-ion batteries. Considering various composition of Li-ion batteries, the next subchapters deeply analyzes the most used cathode (with an emphasis on the LiFePO4, LiMn1/3Ni1/3Co1/3O2) and anode materials (with an emphasis on the Li4Ti5O12). The next chapters describe the used analytical methods: electron microscopy, energy dispersion spectroscopy and thermomechanical analysis. The practical part is devoted to the description of the individual experiments and the achieved results.
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LiFePO4 battery with BMS circuits for a battery drill
Fiala, Václav ; Červinka, Dalibor (referee) ; Vorel, Pavel (advisor)
This bachelor thesis deals with problematics of lithium accumulators. There are listed properties and practical use of lithium accumulators. There is also the chapter of lithium-ion-iron-phosphate accumulators, which will be a practical part of this thesis Next part of the thesis solves a safety electrical circuit system for new lithium batteries which will be able to protect batteries against overcharging or undercharging. In the practical part of the thesis new LiFePO4 batteries for the cordless drill were designed. Also, the mentioned safety electrical circuit was designed and tested.
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Intelligent BMS for lithium batteries
Vašíček, Jakub ; Kazda, Tomáš (referee) ; Vyroubal, Petr (advisor)
This thesis is focused on design of electronic system called BMS, which is necessary for lithium batteries safety operation. The first part contains a brief description of lithium battery design. The following is an overview of the main parameters of this type of batteries. The next part describing various methods of state of charge (SoC) estimation and the ways to ensure uniform charge of each cell. Based on the theoretic analysis, the block diagrams for individual parts of BMS were designed. The following describing device assembly and design of control algorithm. The last part is devoted to measurement of achieved attributes. In conclusion, results of the work are discussed and possibilities of future improvements are suggested.
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Comparison of different types of commercial lithium-ion batteries and their properties under low temperature
Bičák, Tomáš ; Máca, Josef (referee) ; Libich, Jiří (advisor)
The diploma thesis deals with the issue of lithium-ion batteries. Describes development, technologies and materials used. The diploma thesis describes the operating principle, characteristics, advantages and disadvantages. The work is focused on the characteristic properties of commercial lithium-ion batteries under standard conditions and at reduced temperatures. At reduced temperatures, changes in properties due to low temperatures are observed. Furthermore, in this work they compare the measured values with the values given by the manufacturers.
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Alandering Of Li-Ion Electrodes And Its Im-Pact On The Final Capacity Of Lithium-Ion Cell
Svoboda, Lukáš
There is an effort to produce lithium-ion batteries with maximal density of energy, or higher capacity of cell with the same size. Calendaring of electrodes is important part of manufacturing of batteries. Its parameters, mainly the pressure of calendaring and with it related the final compression ratio of electrode layers, affect parameters of battery significantly. It is the process of pressing electrode material coated on current collector with certain pressure and it reduces its porosity and thickness. The aim of this article is determination of suitable level of calendaring that increases specific capacity, but does not reduce its cyclability.
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LiFePO4 battery with BMS circuits for a battery drill
Fiala, Václav ; Červinka, Dalibor (referee) ; Vorel, Pavel (advisor)
This bachelor thesis deals with problematics of lithium accumulators. There are listed properties and practical use of lithium accumulators. There is also the chapter of lithium-ion-iron-phosphate accumulators, which will be a practical part of this thesis Next part of the thesis solves a safety electrical circuit system for new lithium batteries which will be able to protect batteries against overcharging or undercharging. In the practical part of the thesis new LiFePO4 batteries for the cordless drill were designed. Also, the mentioned safety electrical circuit was designed and tested.
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Study Of The Electrode Materials For Li-Ion
Accumulators By Electron Microscopy
Kaplenko, Oleksii
One of the biggest problems with current Li-Ion batteries is thermal stability. Some active materials are more stable than others, but usually high-capacity materials suffer from lower thermal stability. During heating, not only the decomposition of the cathode material, but also the decomposition of other parts of the accumulator, such as anode material, binders and electrolytes, occurs. One of the important advantages of LiFePO4 over other cathode materials is its thermal and chemical stability, which improves battery safety. For this reason, high temperature effects were monitored on individual parts of the complete electrode, and the results are described in this work.
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Study of the electrode materials for Li-Ion accumulators by electron microscopy
Kaplenko, Oleksii ; Čudek, Pavel (referee) ; Kazda, Tomáš (advisor)
The aim of this work is to describe the influence of temperature on the structure and chemical composition of electrode materials for Li-ion accumulators. Theoretical part of this thesis contains described terminology and general issues of batteries and their division. Every kind of battery is provided with a closer description of a specific battery type. A separate chapter is dedicated to lithium cells, mainly Li-ion batteries. Considering various composition of Li-ion batteries, the next subchapters deeply analyzes the most used cathode (with an emphasis on the LiFePO4, LiMn1/3Ni1/3Co1/3O2) and anode materials (with an emphasis on the Li4Ti5O12). The next chapters describe the used analytical methods: electron microscopy, energy dispersion spectroscopy and thermomechanical analysis. The practical part is devoted to the description of the individual experiments and the achieved results.
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Li-ion Batery Management System
Kratochvíla, Lukáš ; Macho, Tomáš (referee) ; Kopečný, Lukáš (advisor)
This thesis is about systems for Li-ion batteries. The system consists of measuring and charging. The main part of system is 3 to 5-Series Cell Li-Ion and Li-Phosphate Battery Monitor chip BQ76920. The result of this thesis is printed circuit board (PCB) with BQ76920 and a box contain PCB and battery pack. Box is designed for robot KAMBOT. The system has been tested and measured and evaluated in this thesis.
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Calandering of li-ion electrodes and its impact on the final capacity of lithium-ion cell
Svoboda, Lukáš ; Kazda, Tomáš (referee) ; Čech, Ondřej (advisor)
There is an effort to produce lithium-ion batteries with maximal density of energy, or higher capacity of cell with the same size. Calendaring of electrodes is important part of manufacturing of batteries. Its parameters, mainly the pressure of calendaring and with it related the final compression ratio of electrode layers, affect parameters of battery significantly. It is the process of pressing electrode material coated on current collector with certain pressure and it reduces its porosity and thickness. The aim of this bachelor thesis is determination of suitable level of calendaring that increases specific capacity, but does not reduce its cyclability.
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