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The effect of temperature on the charging and discharging characteristics of lithium-ion batteries
Doleželová, Eva ; Máca, Josef (referee) ; Libich, Jiří (advisor)
This thesis deals with operation principles of lithium-ion batteries, its degradation principles, capacity fade, materials used, formats, main characteristics, development, uses and mid to high temperature behaviour. The thesis aims to study aging characteristics of commercially available lithium-ion batteries. In the practical part of the thesis, the key parameters of selected types of commercially available lithium-ion batteries were measured under normal temperature conditions. The measurement was repeated at an elevated temperature. Results were analysed and effects of different temperatures on the selected characteristics were concluded both verbally and graphically. A conclusion evaluates short-term and long-term impacts of ambient temperature on rate capability, ageing, capacity fade and longevity.
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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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Modification of PCB cleaning process after removing BGA component
Procházka, Adam ; Bžoněk, Tomáš (referee) ; Řezníček, Michal (advisor)
This bachelor thesis deals with the modification of DPS cleaning process after the removal of BGA components. The thesis is divided into five main parts including the introduction and conclusion. The introduction comprises an assignment and aim of the thesis. The first, theoretical, part then deals with different kinds of soldering, individual types of solders and the rework process itself. The second part examines the whole practical part in detail, from the proposal of the test printed circuit board to its mounting, soldering and subsequent testing. Also, it explains the practical tests for connectors. The third part then describes the board testing by thermal cycling. The last part consists of the summary of results, a comparison of individual soldering pastes and conclusion.
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The effect of temperature on the charging and discharging characteristics of lithium-ion batteries
Doleželová, Eva ; Máca, Josef (referee) ; Libich, Jiří (advisor)
This thesis deals with operation principles of lithium-ion batteries, its degradation principles, capacity fade, materials used, formats, main characteristics, development, uses and mid to high temperature behaviour. The thesis aims to study aging characteristics of commercially available lithium-ion batteries. In the practical part of the thesis, the key parameters of selected types of commercially available lithium-ion batteries were measured under normal temperature conditions. The measurement was repeated at an elevated temperature. Results were analysed and effects of different temperatures on the selected characteristics were concluded both verbally and graphically. A conclusion evaluates short-term and long-term impacts of ambient temperature on rate capability, ageing, capacity fade and longevity.
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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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Modification of PCB cleaning process after removing BGA component
Procházka, Adam ; Bžoněk, Tomáš (referee) ; Řezníček, Michal (advisor)
This bachelor thesis deals with the modification of DPS cleaning process after the removal of BGA components. The thesis is divided into five main parts including the introduction and conclusion. The introduction comprises an assignment and aim of the thesis. The first, theoretical, part then deals with different kinds of soldering, individual types of solders and the rework process itself. The second part examines the whole practical part in detail, from the proposal of the test printed circuit board to its mounting, soldering and subsequent testing. Also, it explains the practical tests for connectors. The third part then describes the board testing by thermal cycling. The last part consists of the summary of results, a comparison of individual soldering pastes and conclusion.
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Modular concept of roller conveyor system
Novotný, Lukáš ; Nosterský, František (referee) ; Pokorný, Přemysl (advisor)
This diploma thesis is dealing with the modular project of a roller conveyer track for transport of europallets with the loading limit of 1200 kg and its use in practise. There are also mentioned possible construction solutions and the actual construction project. It is followed by calculating and modular project of direkt conveyer. Further on, I am dealing with the project of a sliding turntable of cable loops and surfaře covering. In the conclusion, I think out the problems of sensors and a possible operating conveyer.
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