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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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Application of graphite in thermal management of microelectronics
Havlíček, Václav ; Mačák, Martin (referee) ; Vyroubal, Petr (advisor)
Tato práce je zaměřena na zlepšení tepelného managementu mikroelektroniky implementací materiálů na bázi uhlíku, přesněji grafitových fólií, do tepelné architektury mikroelektroniky. Práce začíná vysvětlením současných metod chlazení a výzev v oblasti mikroelektroniky. Poté přechází k běžně používaným materiálům - hliníku a mědi a přidává do výběru i uhlíkové alotropie. Ve druhé části tato práce obsahuje několik příkladů použití pyrolytické grafitové fólie v tepelném managementu mikroelektroniky, prokazuje jeho použitelnost a analyzuje přínosy pro šíření tepla, tepelnou vodivost při dodržení elektrické izolace a možné využití ve flexibilní elektronice.
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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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Chemorezistive gas sensor
Venkrbec, Lukáš ; Pytlíček, Zdeněk (referee) ; Prášek, Jan (advisor)
This thesis deals with the detection of gases. Based on the research, the theoretical part is devoted to the principles and construction of chemical gas sensors, especially the chemoresistive gas sensors, mainly with the active layer consisting of metal oxides and carbon nanotubes. In the second half of the theoretical part the carbon nanostructures, their properties and the methodology of preparation are reviewed. The experimental part deals with the type of support structure, preparation of the active layer and the method of its deposition and he principle of detection. In the results and discussion, the thesis focuses on the detailed processing of the results and the evaluation of the response ammonia, the impact of the modifications and procedures. In the end, the results obtained are compared, both with each other and with the relevant literature.
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Negative Electrode for Sodium-ion batteries
Šimek, Antonín ; Bača, Petr (referee) ; Libich, Jiří (advisor)
This master’s thesis is focused on the research of negative electrode materials for sodium-ion batteries. It contains a general introduction to the issue of batteries, their brief historical development, basic operating principles, key parameters and classification. Attention is paid to lithium-ion batteries, which are the most used technology today. Sodium-ion batteries as their potential replacement, especially in the field of energy storage from renewable sources, are based on lithium-ion technology. Promising candidates for the material for the negative electrode of sodium-ion batteries are sodium titanates. Their synthesis and subsequent electrochemical characterization of electrodes using sodium titanate as the active material are included in the practical part of this work.
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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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Expanded Grpahite as Negative Electrode Material for Aporotic Intercalation Systems
Kaňa, Michal ; Čech, Ondřej (referee) ; Libich, Jiří (advisor)
This thesis deals with lithium-ion batteries. It focuses primarily on the materials which are the basis of negative electrode materials, especially on natural expanded graphite. The aim of this thesis is delineate problems of lithium-ion batteries and the possibilities how to improve their basic parameters such a capacity and current carrying capacity. The first part focuses on the description of the functionality of a lithium-ion battery. The second part focuses on the production of negative electrodes, measuring their properties and characteristics. In the last part, there are evaluated and compared individual negative electrode in the role of host of lithium and sodium ions according to the obtained data and then there are the conclusions draw
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Structure and mechanical properties of thin wall nodular iron castings
Chýlková, Adéla ; Mores, Antonín (referee) ; Roučka, Jaromír (advisor)
The purpose of this final thesis is experimental verification of the influence of graphitic inoculants containing different amounts of trace elements on the structure, mechanical properties and internal homogeneity of thin-walled ductile iron casting. This thesis describes the issue with casting of thin-walled ductile iron. Two melts of thin-walled test plates with thickenesses of 3-, 5- and 8 mm were done in experimental part. A total of six types of inoculations with different content of trace elements were tested. Subsequently, an X-ray irradiation analysis was performed on the samples and hardness, tensile strength and ductility were evaluated. Futhermore, the amount of graphite in structure, graphite shape, graphite size, nodularity, graphite nodule count and volume phases of ferrite and perlite in matrix were analysed in thin-walled ductile cast iron by computer-based image analyzer. Finally, the measurement data were processed into tables and charts and conclusions were formulated. An X-ray analysis proved, that all thin-walled test plates containned shrinkage porosity. Furthemore it was confirmed, that content of manganese in inoculant increases tensile strength and hardness. Also content of zirconium in inoculant increases graphite nodule count.
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