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Preparation and characterisation of ceramic electroactive materials for Na-ion batteries
Vaněk, Martin ; Libich, Jiří (referee) ; Čech, Ondřej (advisor)
Hlavním cílem této práce je charakterizace vzorků titanátů, jako materiálů pro sodíko-iontové (Na-ion) akumulátory. Syntéza některých vzorků je součástí této práce. Charakterizace je zaměřena na elektrochemické vlastnosti, složení a morfologii použitých materiálů. První část se zabývá lithium-iontovými (Li-ion) akumulátory. Byly vybrány, protože jsou ve vědeckých článcích dobře popsány a základní funkční princip je aplikovatelný také na Na-ion akumulátory. Materiály používáné pro katody, anody a elektrolyty následují po krátké části shrnující parametry a konstrukci Li-ion akumulátorů. Následující kapitola je zaměřena na sodíko-iontové akumulátory. Srovnání sodíku a lithia je následováno materiály používanými pro elektrody a elektrolyty (s důrazem na anodové materiály). Třetí část popisuje analytické metody použité pro charakterizaci elektrod a materiálů. Jedná se o elektrochemickou charakterizaci (cyklická voltametrie a galvanostatické cyklování s potenciálovým omezením), morfologii (rastrovací elektronová mikroskopie) a složení (X-ray difrakční spektroskopie). Poslední dvě kapitoly obsahují syntézu a charakterizaci sodného titanátu a charakterizaci dvou vzorků TiO2. Výsledky této práce jsou shrnuty v závěru.
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Investigation of intercalation of alkaline metals in electrochromic devices
Kortyš, Petr ; Špičák, Petr (referee) ; Svoboda, Vít (advisor)
This work deals with investigation of intercalation of alkaline metals in electrochromic devices by the help of the quartz crystal microbalance method. The general aim is to investigate the influence of molar mass and resistance on properties of vanadium pentoxide and tungsten trioxide electrochromic films. The main measuring method used for investigating of interacalation of sodium and lithium ions into these films is the cyclic voltammetry. Drawn graphs reveals that sodium and lithium ions shows different qualities during intercalation, particularly in participation of solvent, therefore, in the influence of molar mass and in structural changes in the films.
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Materials and Components for Lithium-Ion Power Sources
Jirák, Tibor ; Kadlec, Jaromír (referee) ; Paidar,, Martin (referee) ; Vondrák, Jiří (advisor)
The dissertation thesis deals with electrode materials and components for lithium-ion power sources. The thesis works with two different kinds of materials, concretely nanostructured Li4Ti5O12 with spinel basis and LiCoO2 with layered structure. The electrochemical properties, structure and element analysis and utilization possibilities in electrochemical industry of new technological electrode material Li4Ti5O12 were investigated. The influences of admixtures and electrolytes on characteristics of electrode materials with aforesaid active masses were also examined. Low cost price, environmental safety and obtained results of electrochemical measurements and structure analysis refer to wide possibilities of usage electrode material Li4Ti5O12 in the field of electrochemistry.
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XRD characterization of electrodes and electrode materials for electrochemical power sources
Klvač, Ondřej ; Chladil, Ladislav (referee) ; Čech, Ondřej (advisor)
The thesis describes available choices of methods for research of electrochemical power source electrode strcture by x-ray diffraction spectroscopy. At first there is a theoretical computation of difractogram. Then there are discussed possibilities of in-situ and ex-situ techniques as background research. Practical part of thesis compares theoretical assumptions to measurements of lithium and sodium cells, including analyze of crystallographic phases and lattice constants. As a conclusion, there are discussed possibilities of subsequent research.
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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.
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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.
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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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Electrode materials and electrolytes for aluminium-ion accumulators
Benešová, Petra ; Kazda, Tomáš (referee) ; Čech, Ondřej (advisor)
This bachelor thesis presents a topic of aluminum-ion batteries, which have recently attracted great attention owing to their good electrochemical performance and possible use in commercially produced electronics. The paper introduces the basic principles of the function of aluminum-ion accumulators and their advantages, which are a main motivation for further research. The main feature of the theoretical part is an overview of the current state of research on suitable electrode materials and electrolytes for this type of accumulators. The experimental part is focused on the preparation of several carbon-based cathode materials, preparation of the IL-type electrolyte and subsequent cell assembly. The obtained results are evaluated and briefly discussed, taking into account the effects of the cell components and other factors.
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Design and testing of XRD holder for post-mortem analysis of li-ion battery electrodes performed in an inert atmosphere
Klvač, Ondřej ; Chladil, Ladislav (referee) ; Čech, Ondřej (advisor)
The work describes the design and manufacturing of a test device for post-mortem measurements of electrodes of electrochemical cells using X-ray diffraction spectroscopy. The theoretical part describes the diffractometer Rigaku Miniflex 600, for which the product is intended. At the same time, an overview of solutions in various applications is processed here in the form of a recherche. The practical part documents the current development of a new cell, on which tests were performed. Here is an overview of the influence of gases and insulating materials on the resulting data, especially distortion and attenuation. Subsequently, a new design with improved hermetic insulation and sample displacement error correction is described. The principle of operation of the manufactured cell, including the control unit and software, is elaborated in the form of technical documentation. Finally, the functionality is verified by comparing the diffractograms of the powder standards and the graphite electrodes.
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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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