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Fire of batteries in electric vehicles
Blažek, Štěpán James ; Sitek, Tomáš (referee) ; Preisler, Lukáš (advisor)
This bachelor thesis deals with the causes and formation of fires in electric vehicle batteries. The first part summarizes the theory related to types of batteries, used materials, and reviews the phenomenon known as Thermal runaway. The second part of the thesis describes the burning of electric vehicles, providing basic categorization of fire occurrence in electric vehicles and the phenomena accompanying them. The statistical comparison of the current and future development of the number of fires in electrically powered vehicles in the Czech Republic compared to conventional combustion engines, data analysis, and recommendations are summarized in the final part of the bachelor thesis. From the given statistics, it is evident that an electric vehicle is less likely to catch fire, however, it is acompanied by the release of hazardous gases, creating a significant challange in terms of fire extinguishing.
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Lithium and its impact on the environment in lithium battery cell failures
Linney, Phillip George ; Doležalová Weissmannová, Helena (referee) ; Komendová, Renata (advisor)
This bachelor thesis deals with the study of the release of alkali metals and selected heavy metals from battery cells into firefighting water. The battery samples were prepared by superheating them with subsequent explosion and then leaching in distilled water. The change in pH and conductivity compared to distilled water was monitored after a specified time. Flame emission spectrometry and ICP-MS were used to measure elemental concentrations. The measured values of metal contents in aqueous extracts of the battery samples burned in air were compared with those of the samples exploded under water. Some differences were found. A concentration sequence was found for the extracts of the air-burned battery samplesLi+ >> K+ > Na+, whereas for the samples of extracts of batteries burnt in water the concentration sequence Li+ >> Na+ > K+ was found. The concentrations of Na+ ions were around 12.7 mg/l for the samples exploded under water and 275 mg/l thereafter. The K+ concentration was around 19 mg/l for both sample types. Lithium ions were determined the most of all elements measured, averaging 1500 mg/l for air-burned samples and 8200 mg/l for underwater exploded samples. Higher concentrations of Fe, Ni, Cu, Mn and Co were found in the ICP-MS measurements depending on the composition of the battery sample.
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Modeling of temperature phenomena in Li-Ion cells
Grézl, Vojtěch ; Sedlařík, Marek (referee) ; Vyroubal, Petr (advisor)
This thesis deals with the issue of heat generation in Li-ion batteries, which can have a negative impact on the battery properties and functionality. The thesis can be divided into two main parts. The theoretical part focuses on the theoretical description of Li-ion batteries, heat generation, thermal effects, ideal operating temperatures, modelling of these situations, the occurrence of different types of abuse and the consequences that can arise from incorrect or inadequate thermal management. The practical part focuses on the analysis of the results from the discharge temperature measurements for different load values C and the initiation of the effect known as thermal runaway for 18650 Li-ion cell, and then on how to simulate these behavior in the Ansys Fluent.
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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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Influence of temperature on lead acid batteries lifetime
Kopečný, Martin ; Bača, Petr (referee) ; Neoral, Jiří (advisor)
Lead –acid batteries are the most common type of secondary cells used in automotive industry. This diploma thesis deals with the influence of temperature on their lifetime. In the preamble of this work is shortly described their history, division, construction and processes during battery operation. There are noted unfavorable phenomena which have an impact on increasing the temperature inside the battery. The first experimental part is devoted to evaluation the effects of addition on the temperature rise during charging. The second part is focused on conditions simulation in hot areas at the temperature above 30 °C and effects of this temperature on the function of lead – acid batteries.
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Thermal phenomena in lead acid batteries
Kovařík, Lukáš ; Čech, Ondřej (referee) ; Neoral, Jiří (advisor)
This thesis project solve problematic of thermal proces in lead-acid batteries. There are decribed history of lead – acid batteries, distributions of batteries, overview of construction lead – acid batteries and VRLA batteries and is decribed thermal runaway proces and basic termal process. They are listed here practical results and the measurements is concluded.
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Research of thermal effects in lead-acid batteries
Vrba, Marek ; Abraham, Pavel (referee) ; Neoral, Jiří (advisor)
Based on the Czech and foreign literature, this work introduces us to the history, the dividing types of electrochemical cells, specifically deals with the lead-acid battery. The lead-acid battery principle is described and its behavior during charging and discharging. Another topic is the design and distribution. The basic division is the lead-acid accumulator batteries with electrodes submerged and maintenance-free batteries so-called "VRLA", which is gradually coming into force and function of classical battery electrodes are submerged in more demanding applications. Currently, VRLA batteries are used for PSOC system in hybrid vehicles. The practical part of this work deals with PSOC regime that is applied to the experimental cells with electrodes with different admixtures. The results of the influence of admixtures on the durability of articles in PSOC system are summarized at the end of this work.
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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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Investigation of temperature change in lead-acid accumulator for HEV
Tošer, Pavel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The oldest and also most used type of secondary cells is lead-acid accumulator. Basic functional principle stayed same as in foundation time, only operation parameters are still improving (for example one of the most important is lifetime). Significant technical problem is temperature of lead-acid battery and her influence on functionality and running reactions. Master thesis is focused on this section, when is necessary to evaluate new pieces of knowledge in development. The work deals with description existing types of accumulators, further deals with theory of temperature balance and in the end by measured datas and theirs analyzing.
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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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