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Study of intercalation properties of electrode materials based on naturla graphite
Bílek, Lukáš ; Máca, Josef (referee) ; Libich, Jiří (advisor)
This diploma thesis deals with the issue of lithium-ion accumulators. The thesis focuses on the negative electrode of lithium-ion accumulators made of natural graphite. The first part of this thesis points to the issue of electrochemical cells. In the theoretical part the thesis deals with the SEI layer, advantages, disadvantages, characteristics, operating principle and the use of lithium-ion accumulators. The practical part focuses on the electrochemical properties of negative electrode, especially the determination of the diffusion coefficient. Thesis also deals with electrochemical impedance spectroscopy (EIS) and its use in determining the equivalent replacement circuit and calculating the diffusion coefficient.
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Evaluation Of Temperature Influence on Lithium-ion Battery Properties
Zachová, Zuzana ; Libich, Jiří (referee) ; Bača, Petr (advisor)
This diploma thesis deals with monitoring of the influence of temperature on the properties of lithium-ion batteries, especially on the safety and capacity of selected batteries. Chapters 1 and 2 contain a literature review on the subject, describing electrochemical energy sources, especially secondary accumulators, mainly lithium-ion cells. Furthermore, the safety and degradation processes of lithium-ion batteries are discussed and the third chapter describes the design of experiments, realization and outputs of these experiments.
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Study of intercalation properties of electrode materials based on expanded graphite
Vencelides, Lukáš ; Máca, Josef (referee) ; Libich, Jiří (advisor)
The diploma thesis deals with the issue of electrochemical cells and deals in detail with lithium-ion batteries. The thesis describes the history of development of lithium-ion batteries, basic information about lithium and basic types of electrochemical cells. The work is devoted in detail to the description of characteristics and operating principle of lithium-ion batteries with emphasis on the negative electrode and negative electrode materials. Of the negative electrode materials, both the most widely used material graphite and modern materials with a great potential for the future are described. In the measurement methods the work describes methods CV, GCPL and EIS. Great emphasis is placed on the explanation of the principle of the function of electrochemical impedance spectroscopy and its application in measurement of electrochemical properties of materials used in lithium-ion batteries. There is also described the procedure of calculation of diffusion coefficients using the results of electrochemical impedance spectroscopy. In the practical part, two methods are used to calculate the diffusion coefficients of lithium ions into the negative electrode made of expanded flake graphite using the results of a series of electrochemical measurements.
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Effect of Compaction Pressure to the Electrochemical Properties of the Electrodes for Li-S Accumulators
Jaššo, Kamil
Over the last decade, demand for batteries increased a lot thanks to the wearable devices and electric cars. The current trend in all industries is reducing the size and weight of batteries and increasing their capacity. The demand for even more powerful batteries is often faced with theoretical and practical limits of the technology. Battery industry compared to other industries is just slightly behind and batteries became a limiting factor for technologies.The purpose of this experiment is to describe the impact of compaction pressure on the electrochemical properties of the positive electrode for lithium-sulfur batteries.
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Lithium-ion cell: Treatment of Natural Graphite by Lithiation Method
Bílek, Lukáš ; Kazda, Tomáš (referee) ; Libich, Jiří (advisor)
This bachelor thesis deals with the issue of lithium-ion accumulators. The thesis focuses on the negative electrode of lithium-ion accumulator made of natural graphite. In the theoretical part the thesis focuses on the characteristics, the operating principle and the use of lithium-ion accumulators. Negative electrode materials are also analyzed. The main topic of the thesis is the use of lithiation method which suppresses irreversible capacity losses with the improvement of the capacitance and current characteristics of the battery.
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Lithium-ion battery: Negative electrode materials based on graphite
Vencelides, Lukáš ; Máca, Josef (referee) ; Libich, Jiří (advisor)
This bachelor‘s thesis deals with the isuess related to the lithium-ion batteries. The history of development of lithium-ion batteries, current commercially available and developed types are described in the thesis. The thesis deals in detail with the description of the characteristics and operating principle of lithium-ion accumulators with emphasis on negative electrode and negative electrode materials. The goal of the thesis is technological and electrochemical characterization of graphite negative electrode materials. Two types of natural graphite are used in the thesis, both are potenti-galvanistically analyzed from the point of view of capacitance and current characteristics.
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Optimization of Electrode Preparation Technology for Lithium-Ion batteries
Zahálka, Patrik ; Máca, Josef (referee) ; Libich, Jiří (advisor)
This bachelor thesis deals with technological parameters of electrode production proces optimization for lithium-ion batteries. The thesis focuses on the negative electrode based on natural graphite. The first part presents a brief introduction to lithium-ion batteries and current status research. In the theoretical part the thesis focuses on the study of the structural and electrochemical properties of natural graphite and the operating principle of lithium-ion accumulator. The practical part solves optimization of electrode parameters, pressing pressure and electrode layer thickness. The capacitive and current characteristics of electrodes based on natural graphite have been analyzed and compared to the process parameters mentioned above.
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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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Technologies for storing electrical energy in electric vehicles
Zdražil, Marek ; Walek, Agata (referee) ; Langerová, Petra (advisor)
Tato bakalářská práce je zaměřena na technologie pro ukládání elektrické energie, s důrazem na jejich použití v elektrických vozidlech. První kapitola se zabývá historickým vývojem technologií pro ukládání elektrické energie a jejich použitím v prvních elektrických vozidlech. Dále popisuje elektrická vozidla, která byla sporadicky vyráběna v průběhu dvacátého století, až po devadesátá léta, kdy tato technologie opět nabyla na atraktivitě. V další části nalezneme rozdělení současných elektromobilů a zástupce těchto kategorií mezi automobily vyráběnými v současnosti. Třetí část se věnuje technologiím používaným v současnosti, či nedávné minulosti. Následně je uveden přehled technologií, které by mohly do budoucna nahradit současné systémy, nebo dokonce konvenční spalovací motory.
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