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The influence of zinc ion on possitive elektrode of Ni-Zn accumulators
Karásek, Stanislav ; Novák, Vítězslav (referee) ; Chladil, Ladislav (advisor)
This thesis deals with the establishment of zinc ions at the positive electrode of nickel-zinc batteries. The aim of the study was to measure the impedance characteristics of the positive electrode in various states of charge and observing the effect of ZnO on the changes of impedance spectra. The theoretical part is focused on nickel hydroxide as a construction material for positive electrode and its behavior during cycling in the electrolyte. The experimental part describes in detail the manufacture of the electrode system and the preparation of electrolytes with different degrees of saturation with zinc oxide. The cells were cycled and measured using impedance spectroscopy. The measured impedance curves were simulated with equivalent circuits for a better understanding of the ongoing processes.
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Exploring the influence of pressure on the life of lead acid batteries for hybrid electric vehicles
Pospíchal, Martin ; Tošer, Pavel (referee) ; Bača, Petr (advisor)
The lead-acid batteries used in hybrid electronic vehicles HEV operate in high-rate mode in a state of partial charge PSoC. It occurs when the degradation mechanisms related to irreversible sulphation and negative electrodes are a limiting factor in the life of lead-acid batteries. The electrode system was applied to experimental pressure cells of different sizes. Exp. cells were subjected to measurement and evaluation of potential negative electrode, a negative active mass resistance, contact resistance of transition collector - the active mass with the evaluation and measurement of pressure fluctuations within four PSoC runs.
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Thick-film sensors for heavy metals detection
Polický, Jiří ; Adámek, Martin (referee) ; Prášek, Jan (advisor)
This work covers an area of heavy metals detection using thick-film sensors. Fabrication of screen-printed thick-film sensor and electrochemical analytical methods for detection of chemical elements in aqueous solutions are described in this work. Several commercial and own prepared thick-film pastes were used for carbon based working electrodes. The electrochemical properties of the pastes were examined by cadmium ions detection in potassium chloride solution using differential pulse voltammetry. The best results were achieved on the electrode made of direct grown carbon nanotubes on the electrode layer NM22. A detection limit 20×10-6 mol l-1.was reached with this working electrode material during oxidation process.
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Modification properties of MnOx based positive electrode for AFC
Kamrla, David ; Bača, Petr (referee) ; Novák, Vítězslav (advisor)
The subject of this graduation thesis is low-cost alkaline power cells and especially electrodes with alternative catalyst made of MnOx + dopant. The thesis expands the bachelor´s thesis [1] and previous research [4] [12] [13] [14]. Volt-ampere characteristics and power characteristics of the katodes for AFC, subsidized with various dopants, are the outcome of this project. The project presents the optimalisation of preparation process of AFC electrodes. The aim is to prepair several electrodes with identical construction, which varies only with the type of the dopant.
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New electrode structures for alkaline accumulators
Fusek, Petr ; Novák, Vítězslav (referee) ; Vrbický, Jiří (advisor)
Master´s thesis is focused on development of electrodes used in alcaline accumulators, by using new kinds of materials and compounds. Basic possitive eletrode was made of nickel, on this electrode were applied new layers of Ni(OH)2 by using the method called electrodeposition. For electrodeposition was used solution with Ni(NO3)2 in diverse concentrations. Later on, this material was enriched with aluminium admixtures to increase stability of alfa modification in Ni(OH)2. These concentrations were measured and analysed in diagrams. For measurement was used device Biologic. The diagrams were commented with recommendations for production use in accumulators.
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Conducting polymers and their use in supercapacitors
Gottwald, Tomáš ; Zatloukal, Miroslav (referee) ; Dvořák, Petr (advisor)
This work deals with the issues of using conducting polymers for supercapacitor electrodes and optimizing the technological process for their production. The work focuses on optimizing the amount of polymer used in order to achieve the most capacity. The methodology consists of creating an appropriate experimental electrode and subsequent measuring its associated capacity with BioLogic. This approach leads to creating charts which show the dependencies of capacity on the amount of polymer used.
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Optimization of thick-film electrochemical sensor's electrode system
Cupal, Miroslav ; Adámek, Martin (referee) ; Prášek, Jan (advisor)
Master’s thesis deals with thick/film sensor’s electrodes optimization. The aim of this work is to determine how the geometric size and shape of the electrodes affect the output current response. Technology and electro-analytical method is described in the theoretical part. The practical part is aimed at thick-films electrodes and sensors optimalization. It is here each optimization TLV electrodes in terms of their impact on the size of the output current response three-electrode electrochemical system using standard electrodes. Similarly, there is a study of the effect size performed on one common electrode free-electrodes sensor. Finally, there are studied various forms of electrode area three-electrode thick-film sensor in terms of their effect on the output current response. Summarized results are described in the final part of the work.
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