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Comparison of parameters of selected types of commercial lithium-ion batteries
Špina, Martin ; Libich, Jiří (referee) ; Bača, Petr (advisor)
This thesis deals with operation principles of Lithium-ion battery. It evaluates its characteristics, advantages, and disadvantages. Technological processes and materials used in manufacturing and recycling are also discussed. Practical part of the thesis evaluates initial capacity of given Li-ion cells at different loads. Batteries are then cyclically charged and discharged, and its capacity and other parameters are determined. Electrochemical impedance spectroscopy data are also taken and evaluated for batteries in new-like condition, used batteries and cycled batteries as the capacity fades.
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Evaluation Of Temperature Influence on Lead-Acid Battery Properties
Malyi, Denys ; Zimáková, Jana (referee) ; Bača, Petr (advisor)
This master's thesis acquaints with the current state of research into phenomenon the Thermal runaway effect in lead-acid batteries. The literature search presents individual theories that try to explain the TRE phenomenon. The second chapter presents proposed experiments that will monitor temperature changes in lead-acid batteries of various designs. In the practical part of the master's thesis, the performed experiments, their courses, and their evaluation are described.
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Modified glass fibers as additives of the negative electrode of a lead-acid battery
Zbožínek, Tadeáš ; Zimáková, Jana (referee) ; Bača, Petr (advisor)
This bachelor thesis is focused on the working of lead-acid batteries in hybrid electronic vehicles. The goal is to increase the negative electrode characteristics of VRLA batteries. The negative electrode suffers significant degradation in the partial-state-of-charge mode, which is used for these vehicles. When the VRLA battery is being used in the partial-state-of-charge mode, premature loss of capacity occurs due to sulfation of the negative active mass. For these reasons we are trying to improve active mass with additives, which Is expected to interrupt the unwanted processes, that leading to capacity loss. We are focusing on a specific additive in form of glass fibers, which exhibits similar positive effect on the lifetime of the battery as a carbon additive. The surface of glass fibers will be modified. Afterwards, the influence of the modified glass fibers on the lifetime of the battery will be observed.
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Evaluation Of Temperature Influence on Lead-Acid Battery Properties
Langer, Martin ; Zimáková, Jana (referee) ; Bača, Petr (advisor)
This work deals with lead-acid batteries, their properties and individual types that are available on the market. The temperature dependences of the battery parameters at different ambient temperatures and at different discharging and charging modes are measured here. The theoretical part of the work deals with electrochemical cells in general, description of their main parts and principles of operation. The work analyzes the types of batteries used, their advantages and negatives. In the case of a lead-acid battery, its internal structure and the function of the electrodes and the electrolyte are taken into account. Furthermore, a description of individual possible negative phenomena that take place in lead-acid batteries and contribute to the end of their service life is included. In the practical part, 6 batteries are tested at different charging currents, which provides information about their behavior both during discharge and at the time of charging. During the experiments, testing is not only performed at room temperature, but the batteries are also exposed to high temperatures up to 75 ° C.
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Microscopic Observations of Active Mass Structures of the Negative Electrode of a Lead-Acid Battery
Zimáková, Jana ; Dostál, Zdeněk (referee) ; Kohout,, Jan (referee) ; Bača, Petr (advisor)
This doctoral dissertation deals with the study of the effect of additives on the properties of the negative electrode of a lead-acid battery. The work focuses on the investigation of the additive/base material interface for the negative electrode (so-called active mass) using atomic force microscopy (AFM). A lead sheet was used as the base material, on which the given additive was applied. The effects of carbon, TiO2, glass fibers and Indulin AT were specifically investigated. The negative electrode was cycled by a potentiostat in a defined manner and the morphology of the electrode surface was continuously scanned by AFM. This created a time sequence of images on which events on the surface of the electrode during its charging/discharging were captured. These records serve to better understand the effect of additives on the resulting properties of constructed lead-acid cells, specifically on the ability to form or dissolve PbSO4 crystals, which are formed during cell discharge and are responsible for the decrease in total capacity - gradual surface sulfation.
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Design of key performance metrics
Kmeť, Lenka ; Jandová, Kristýna (referee) ; Bača, Petr (advisor)
This document deals with process approach and it´s use in measuring companies performance. It presents an overview of individual approaches, from traditional containing only financial indicators to modern ones using non-financial indicators and incorporating into the measurement the areas related to customers employees and more. The work also mentions the Quality Management System contained in ISO 9001: 2015 and it´s approach to performance measurement. The chapter about metrics covers performance measures, in particular key performance indicators, their purpose, properties and distribution. Here are also presented the procedures for their determination and the pitfalls to be taken into consideration in their selection and use. Next chapters are devoted to the compilation of a metric system of specific companies.
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Evaluation Of Temperature Influence on Lithium-ion Battery Properties
Zachová, Zuzana ; Libich, Jiří (referee) ; Bača, Petr (advisor)
This diploma thesis deals with monitoring of the influence of temperature on the properties of lithium-ion batteries, especially on the safety and capacity of selected batteries. Chapters 1 and 2 contain a literature review on the subject, describing electrochemical energy sources, especially secondary accumulators, mainly lithium-ion cells. Furthermore, the safety and degradation processes of lithium-ion batteries are discussed and the third chapter describes the design of experiments, realization and outputs of these experiments.
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Negative lead-acid battery electrode for hybrid electric vehicles
Dvořáček, Daniel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The thesis briefly discusses the issue of electrochemical power sources, especially with a focus on lead-acid batteries operating in modes that are typical of hybrid electric vehicles. The theoretical part of the thesis should be a good basis for the subsequent practical part, in which several experimental electrodes and their parameters will be performed and evaluated. The output of the practical part will be conclusions regarding the influence of different variants of modified carbon used as an additive in the active material of the negative electrode on the capacity and life of cells
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Methodology of identification of revisions and inspections of technical equipment for a manufacturing company based on the requirements of ISO 45001
Valenta, Jakub ; Jandová, Kristýna (referee) ; Bača, Petr (advisor)
This work deals with the issue of inspections and revisions of technical equipment according to safe operation standards on the basis of OSH and FP requirements. In the introduction, these fields of work safety and fire protection are described, which will be used in later parts of the work. Subsequently, the term „technical equipment“ and subcategories of this issue are defined, with each of the subcategories being specifically approached. As a result, the thesis describes why it is necessary to regularly inspect the technical equipment, while the individual types of inspections are subsequently defined. This is accompanied by the distribution of the person’s rights to carry out individual inspections and the distribution of responsibility for the inspections carried out. The acquired knowledge is then used to create a model of the process of regulation of inspections and revisions and to create an overview of periodic inspections and revisions of technical equipment for a manufacturing company. This model and review of inspections are then considered the output of this bachelor’s thesis.
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