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Impedance measurements of lead-acid accumulators
Vaculík, Sebastian ; Bača, Petr (referee) ; Abraham, Pavel (advisor)
The main aim of this paper is to contribute to the elucidation of electrochemical processes. These processes occur in the investigated experimental lead-acid cell. For this purpose, electrochemical impedance spectroscopy was used. There are two methods of measurement presented. First one is used to measure impedance between electrodes. Second one is used to measure impedance of collector ribs inside positive or negative electrode. The results are represented by electrical equivalent circuits, whose elements are described in detail in the theoretical part.
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Impedance Measurement of Lead-acid Accumulator
Abraham, Pavel ; Dostál, Zdeněk (referee) ; Jareš, Petr (referee) ; Bača, Petr (advisor)
This dissertation deals with impedance measurements of lead-acid accumulator. Main aim was to study recent problems of impedance measurements of lead-acid accumulator and most importantly to extend difference method and also to interpret its results. The original DC difference method was developed earlier at our Power Sources Laboratory of Department of Electrical and Electronic Technology. The DC difference method and also the new AC difference method are both non-destructive, which means that experimental data can be obtained in situ. New method provides more accurate set of information because of its wide frequency range nature. Electrodes of lead-acid accumulator were analysed with special attention to collector / active mass double layer and to active mass itself. Various states and operation regimes were investigated. Obtained data contributed to better understanding of involved degradation mechanisms. Main aim of other experiment was to observe and interpret corrosion rates of electrode collector composed of various lead alloys. Last but not least charge and discharge regimes e.g. 100% deep of discharge regime, partial state of charge (PSoC) regime and pulse charge regime were analysed. BioLogic VSP was the device used for almost all experimental measurements. It takes a lot of effort to optimise VSP operation regime. Best operation regime of VSP for the difference method was suggested too.
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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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Improving of use properties of lead-acid accumulator
Szabó, Jaroslav ; Tonar, Karel (referee) ; Abraham, Pavel (advisor)
Lead-acid accumulators are the oldest and most common type of secondary cells. There are still some problems to solve. Grid corrosion in sulphuric acid is one of them, which reduced lifetime of lead-acid accumulators. The first part of work is focusing on a general theoretic description of lead – acid accumulators. Following is a description of the workstation and method of measuring. The final part of the text is measuring on an experimental cell.
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Degradation mechanisms of lead-acid batteries
Pavlů, Michal ; Abraham, Pavel (referee) ; Bača, Petr (advisor)
This work deals with problems of degradation mechanisms of lead-acid batteries. For a better understanding of the diverse effects that cause the degradation are analyzed and the physical explanation of each of the degradation mechanisms. The paper describes the measuring method by which they examined the different manifestations of degradation mechanisms. At the conclusion of works are carried out measurements in which it is possible to trace the manifestations of the various degradation mechanisms in lead battery taking place mainly on the active surface electrodes.
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Impedance measurement of lead-acid accumulator properties
Vaculík, Sebastian ; Neoral, Jiří (referee) ; Abraham, Pavel (advisor)
This work deals with the new and unique four-point method measurement of the impedance characteristics for experimental positive electrode. The theoretical part provides a short introduction to the electrochemical power sources, including the lead-acid batteries, which were used for measurement. Furthermore, there is description of the principle of electrochemical impedance spectroscopy and analysis of obtained data by using the equivalent circuit, consisting of passive components. The experimental section is devoted to the description of the device, which is used for realization of connection of electrodes with Potenciostat VSP, and program which is used for the simplification of processing of results. The main aim of this bachelor thesis is to get better understanding of lead-acid accumulators and impedance measurements. At practical part of the thesis I performed first measurements by two-step method based on electrochemical impedance spectroscopy.
|
|
|
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.
|
|
|
Impedance measurement of lead-acid accumulator properties
Vaculík, Sebastian ; Neoral, Jiří (referee) ; Abraham, Pavel (advisor)
This work deals with the new and unique four-point method measurement of the impedance characteristics for experimental positive electrode. The theoretical part provides a short introduction to the electrochemical power sources, including the lead-acid batteries, which were used for measurement. Furthermore, there is description of the principle of electrochemical impedance spectroscopy and analysis of obtained data by using the equivalent circuit, consisting of passive components. The experimental section is devoted to the description of the device, which is used for realization of connection of electrodes with Potenciostat VSP, and program which is used for the simplification of processing of results. The main aim of this bachelor thesis is to get better understanding of lead-acid accumulators and impedance measurements. At practical part of the thesis I performed first measurements by two-step method based on electrochemical impedance spectroscopy.
|
|
|
Impedance Measurement of Lead-acid Accumulator
Abraham, Pavel ; Dostál, Zdeněk (referee) ; Jareš, Petr (referee) ; Bača, Petr (advisor)
This dissertation deals with impedance measurements of lead-acid accumulator. Main aim was to study recent problems of impedance measurements of lead-acid accumulator and most importantly to extend difference method and also to interpret its results. The original DC difference method was developed earlier at our Power Sources Laboratory of Department of Electrical and Electronic Technology. The DC difference method and also the new AC difference method are both non-destructive, which means that experimental data can be obtained in situ. New method provides more accurate set of information because of its wide frequency range nature. Electrodes of lead-acid accumulator were analysed with special attention to collector / active mass double layer and to active mass itself. Various states and operation regimes were investigated. Obtained data contributed to better understanding of involved degradation mechanisms. Main aim of other experiment was to observe and interpret corrosion rates of electrode collector composed of various lead alloys. Last but not least charge and discharge regimes e.g. 100% deep of discharge regime, partial state of charge (PSoC) regime and pulse charge regime were analysed. BioLogic VSP was the device used for almost all experimental measurements. It takes a lot of effort to optimise VSP operation regime. Best operation regime of VSP for the difference method was suggested too.
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