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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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Solder Joint Strength Measuring
Konečný, Aleš ; Chladil, Ladislav (referee) ; Starý, Jiří (advisor)
This thesis studies the definition of solder joint strength and its contributing factors. It also evaluates the options provided by using a MARK10 M5-100 digital force gauge with MESURgauge software for measuring solder joint strength and practically tests solder joint strength of SMD components sized 1206, 0805 and leads of THT components. Based on this, the thesis suggests further tests to be done in order to evaluates the degree to which each factor affects solder joint strength and suggests possible improvements of testing procedures used. These tests and improvements will be explored by a follow-up thesis, which will also be creating a part of a guide to a new laboratory exercise.
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Measurement of dielectric properties of liquid fuels for automotive power units
Redr, Martin ; Čech, Ondřej (referee) ; Chladil, Ladislav (advisor)
This bachelor thesis dealt with measuring of dielectric properties of propellants. The aim of the thesis was to find out differences between dielectric quantities of propellants from various manufacturers and in different proportions of refined to so-called bio-components. The theoretical physical principles of dielectric substances – permittivity and dissipation factor were described. In the thesis the most famous electrical insulation fluids whose dielectric characteristics are similar as propellants were mentioned. Furthermore, the study about dielectric properties of propellants and chosen fuels on the Czech market were mentioned. In the experimental part of the thesis, selected fuel samples at varying frequency and temperature were measured. These results were then evaluated and compared.
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Monitoring of Electrode Changes of Negative Electrode for Lead-Acid Batteries by Operando Confocal Microscopy
Hálová, Hana ; Vanýsek, Petr (referee) ; Chladil, Ladislav (advisor)
The thesis is focused on the laser microscopy observation of the negative electrode for lead-acid batteries during their cycling. The surface changes are evaluated during both deep cycling and PSoC (Partial State of Charge) cycling. The mode leads to gradual degradation of the negative electrode – mostly because of irreversible sulfation. The speed of the sulfation can be influnced by additives of the negative active mass added already during production process. The active mass was firstly examined by electron microscope and X-ray diffractometer. The crystal growth during cycling was observed using confocal microscope Olympus Lext OLS4100.
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Optimalisation of coposite materials for civil engineering
Kazda, Tomáš ; Chladil, Ladislav (referee) ; Novák, Vítězslav (advisor)
This work is focused on optimalisation of coposite materials for civil engineering. In the theoretical part of the project is introduction of the composite materials and materials which are used for their production. There are also concerned their properties and possible application areas. In conclusion of theoretical part this project is a summary of the possible use of composite materials. The practical part compares the characteristics of the different types of composites made in terms of conductivity and the rate of corrosion.
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Vanadium cells as a source and storage of energy
Langr, Pavel ; Chladil, Ladislav (referee) ; Novák, Vítězslav (advisor)
This semestral thesis deals with problematics of redox flow batteries, especially vanadium batteries. The first part is focused on describing basic terms, describes redox batteries and explains chemical processes. It also deals with vanadium batteries properties and construction. The second part of the thesis describes diagnostic method of spectroscopy, which seems to be very perspective for examining attributes of vanadium redax batteries.
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Nonplatinum catalysts for polymer exchange membrane fuel cells
Talába, Michal ; Chladil, Ladislav (referee) ; Novák, Vítězslav (advisor)
This work brings a study about non-platinum catalysts, alkaline membranes and methods that interprets catalytic activity. Work deals with a research on non-platinum catalysts based on MnO2 with addition of support substances, measuring of their properties using cyclic voltammetry and hydrodynamics theory. Also a fuel cell measurement of catalytic materials on PVA membrane is executed. The outcome of this work is evaluation of voltammetry and fuel cell measurements. The results of all methods are compared too.
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Preparation of Epoxy Based Insulating Materials Filled by Nanoparticles
Mockovčiak, Kristian ; Čech, Ondřej (referee) ; Chladil, Ladislav (advisor)
The present thesis deals with the preparation of epoxy insulating materials filled with nanoparticles and its electrical properties. Experimental samples are made of epoxy resin as a matrix and titanium dioxide nanoparticles (TiO2) as nanofillers in 0.5, 1 and 3 percent filling. Temperature dependencies of internal resistivity, relative permittivity and loss factor are measured on nanocomposite samples. The influence of the filler on the resulting electrical properties of the polymer used is discussed.
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A Study of Phenomena that Limit the Life-Span of Ni-Zn Secondary Cells
Chladil, Ladislav ; Oriňáková,, Renáta (referee) ; Vanýsek,, Petr (referee) ; Novák, Vítězslav (advisor)
This dissertation is focused on the study of selected additives and their effect on positive and negative electrodes of Ni-Zn secondary cells. The first group of additives consists of the inorganic compounds that reduce zinc oxide solubility and thus prevents shape changes of the zinc electrode. The second group contains organic additives that have the beneficial effect of dendrite growth prevention. All additives were examined in relationship to their compatibility with the positive electrode and to their effect on the zinc electrode dendrites inhibition, hydrogen evolution and corrosion inhibition. Moreover, the study of decomposition kinetics of supersaturated zincate solution with the first group of additives was performed. Finally, a short study of pulse regime charging mode with regard to dendrites inhibition was performed and evaluated.
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