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Causes of Premature Capacity Loss of Lead-Acid Accumulators Operating in PSoC Mode in Hybrid Electric Vehicles
Bilko, Radek ; Jareš, Petr (referee) ; Dostál, Zdeněk (referee) ; Bača, Petr (advisor)
This thesis is completion of whole stage of researches and it is a result of existing need of increase efficiency, utilization rate and service life of lead acid batteries VRLA planned for utilization in hybrid electric vehicles in mode of partial state-of-charge PSoC. During the application of mode PSoC at lead acid battery occurs irreversible sulfation of negative electrodes and thus to loss their charging capability. This phenomenon, according to the latest trend called PCL3, isn´t connected with subsequently referred effects PCL1, PCL2, show up on positive electrodes. Result of this thesis is finding a new types of additives, determine their optimum amount and size in such a way that innovated composition of negative active materials be able to resist sulfation of negative electrode during operation in mode PSoC. Part of the effort to clarify actions ongoing on negative active material and causes non-returnable sulfation electrodes is also monitoring of structural changes electrode active material by using environmental scanning electron microscope, which helped to clarify processes related with loss of capacity in mode PSoC. Special attention during reserches was focused on study of the properties contact layers between collector and electrodes active material and itself active materials lead-acid battery druring exploitation. There were gain new information about influence repeated cycling of (charging, discharging) the critical area of the electrodes. Measurements was carried out on specially prepared experimental electrodes DC Difference Method, this enabled obtain data in situ.
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Conductive ceramic as additive in the lead-acid accumulators
Šrut, Martin ; Křivík, Petr (referee) ; Bača, Petr (advisor)
Lead-acid batteries are most used secondary electrochemical power sources. Their basic principle has remained the same for several years; only the operating parameters are in development. Lead-acid batteries are used in hybrid electric vehicles (HEV), which operates in the partial charge PSoC. Sulphation is one of the possible failures lead-acid batteries in the HEV, especially the negative electrode. By adding additives to the negative active mass can reduce the rate of sulphation and increase ability to accept an electrical charge by negative electrode.
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The effect of pressure on the electrode system in lead acid batteries with experimental glass fibers aditives electrodes
Fryda, Daniel ; Vaculík, Sebastian (referee) ; Bača, Petr (advisor)
This Master’s thesis deals with the lead-acid batteries, which are alternativ power supply. The lead-acid batteries are the oldest type of battery cells. This lead-acid batteries have a great use in hybrid electric vehicles (HEVs), which operate in different modes of vehicle operation. These modes correspond to the reactions taking place during discharging and charging the battery. The lead-acid batteries in hybrid electric vehicles work in mode PSoC. The practical part of the Master`s thesis examines how the characteristics of lead-acid batteries are modified due to admixture of glass fibers into negative active material and application of pressure to the electrode system.
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The examination of the effect of titanium dioxide on the properties of lead-acid batteries
Mlýnek, Martin ; Vaněk, Jiří (referee) ; Bača, Petr (advisor)
Despite, considerable advances in technologies for storing electrical energy, lead-acid batteries are still the most widely used these days even it was invented more than a century ago. The functionality remains the same since its invention. Today´s time puts certain pressure on improving some aspects of the functionality like, heat management, charging and discharging speed, capacity and durability etc..... This bachelor´s thesis is based on the last mentioned, Durability,. The work presents the theory of acid batteries with the history of chemical reaction, technological production processes and battery construction. It is followed by a chapter about titanium and titanium dioxide as an addition of negative active mass where all the aspects are being examined in this work.
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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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Investigation of carbon effect in negative active mass on lead-acid accumulator for HEV.
Tonar, Karel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The lead-acid bateries for hybrid-electric vehicle (HEV) working under high-rate partial-state-of-charge (HRPSoC) conditions. The negative plates of lead-acid batteries have low charge acceptance. The cycle life of the batteries is dependent on the rate accumulation of PbSO4 on the negative plates. Addition of some carbon or graphite forms to the negative paste mix improves the charge efficieny and slows down sulfation of the negative plates. The master’s thesis wants to explain the contribution of electrochemically active carbon (EAC) additives to the mechanis of the electrochemical reaction of charge of the negative plates.
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Using lead-acid accumulators in hybrid electric vehicle regime
Hejdiš, Roman ; Novák, Vítězslav (referee) ; Bača, Petr (advisor)
The master´s thesis discuss characteristics of hybrid electric vehicles and lead-acid accumulators applied in car industry. It compares classic and alternative drive in cars, descibes classification of hybrid drives and its characteristics. Further work disscus lead-acid accumulators which focuses on VRLA accumulators applied in hybrid electric cars. Practical part contains a construction description of negative electrode and experiment, which studied influence of various amount addition of carbon on attributes of these electrodes.
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