National Repository of Grey Literature 39 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Thin-film systems
Kuchařík, Jan ; Máca, Josef (referee) ; Zatloukal, Miroslav (advisor)
This bachelor thesis concerns to create of thin films on various types of substrates. In the theoretical parts is an overview of the formation of thin films using several techniques. The thesis contains an overview of substrate cleaning processes before the deposition of layer plates and tools for evaluating their properties. Finally, the masking method is discussed. In the experimental part, the acquaintance with the NP - 12 sputtering device and the production of samples took place. The adhesion of the produced samples was evaluated. Electrolysis of samples with titanium coated followed. Finally, the silicon substrate was masked.
High efficiency control circuits for LEDs
Havlík, Vojtěch ; Máca, Josef (referee) ; Vyroubal, Petr (advisor)
The aim of this diploma thesis is to design two different switching power supply circuits with integrated circuits suitable for controlling of LED. The theoretical part describes the principles of two main switching converters topologies – buck and boost. Furthermore, a universal H-bridge structure of switching supply is described. This is compared with the typical switching supply design. Based on specified requirements, two circuits are designed with selected IO which are suitable for using in the automotive industry. Their function and typical schema are described. In the practical part is realized design with both selected IC, choosing components and layout PCB. Set of tests are carried out with manufactured samples. Based on measured results are performed optimalization of samples, which are tested also. In the end of this thesis both samples are compared in terms of function, efficiency and EMC.
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.
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.
Long-term influence of low-flammable electrolytes on negative electrodes
Valoušek, Michal ; Jandová, Kristýna (referee) ; Máca, Josef (advisor)
The thesis deals with the influence of low-flammable electrolytes on negative electrodes. The thesis describes materials used in lithium-ion batteries and functions of individual components. There is also a description of conductometry and electron microscopy, which is used in the practical part, ie during measurement. All findings are summarized at the end of the thesis.
Influence of flame retardant on negative electrodes in lithium - ion accumulator
Buchta, Martin ; Libich, Jiří (referee) ; Máca, Josef (advisor)
This diploma thesis deals with problematics of electrochemical power sources with focus on lithium accumulators, their construction and functioning priciple. It also discusses the safety of li-ion batteries with respect to their flammability. In addition, the flame retarders, which help to lower the flammability, are listed. The thesis describes Cyclic Voltammetry and Galvanostatic Cycling with Potencial which are lithium-ion cell measuring methods. In the last part, the influence of various flame retarders on negative electrode is compared based on the conducted tests.
Negative electrodes for sodium ion batteries
Šátek, Dominik ; Libich, Jiří (referee) ; Máca, Josef (advisor)
This bachelor thesis deals with sodium-ion accumulators with focus on negative electrode, introduces basic terms in the field of secondary cells and describes production of accumulators. The result of this work are tested electrodes based on natural carbon and sodium metatitanate. These electrodes are then compared with each other and evaluated.
Impact of technological parameters on electrochemical properties of negative electrode in lithium-ion battery
Živčic, Samuel ; Máca, Josef (referee) ; Libich, Jiří (advisor)
This bachelor thesis deals with the issue of li-ion batteries and consists of two main parts. The first part of the thesis deals with a theory. It describes the functionality of electrochemical cells, especially li-ion cells. Operational principle of the cell is discussed, with the main focus given on negative electrode (anode) and the material it consists of, the natural graphite, mainly his electrochemical properties. Last chapter of theory describes expected impact of technological parameters on electrochemical properties of negative electrode. The second part of the thesis is the practical part. First, it describes procedure of making electrodes in laboratory and afterwards it provides an explanation of used measuring methods, steps taken during the measurement, and the results of the measurements. At the end of the thesis, the influence of pressure and layer thickness on electrochemical properties of natural graphite and on capacitive and current characteristics of negative electrode is evaluated.
Electrochemical properties of negative electrode made from natural and expanded graphite
Priščák, Juraj ; Máca, Josef (referee) ; Libich, Jiří (advisor)
This bachelor thesis deals with lithium-ion accumulators from the prespective of its structure, operation and using. It studies anode materials, focusing on natural and expanded graphite. Explains operation and structure of lithium-ion accumulator. The second part of thesis aims on manufacturing of anode electrodes of natural and expanded graphite. Deals with their measurement of its current a capacity rating. The aim of the thesis is how characteristic of accumulator depends on features of anode materials. In conclusion is sum up and comparation both materials on base of their measurement.
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.

National Repository of Grey Literature : 39 records found   1 - 10nextend  jump to record:
See also: similar author names
2 Maca, Jakub
1 Máca, Jan
2 Máca, Jiří
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