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21	Characterization of the gas composition inside NiMH batteries during charge using GC-MS Niklasson, Lovisa January 2018 (has links) The aim of the project was to develop a method to measure and studythe degree of activation of the negative electrode (MH) in a NiMH battery.This was done by characterization of the gases produced during charge of a battery – O2 and H2 – using a Gas Chromatograph. The current applied in the very first charge of the battery was varied in order to examine how this affects the gas evolution. In the developed method, batteries were charged to 8Ah with 9A, after which a gas sample was taken and analyzed with Gas Chromatography. An additional goal was to use the method to examine the difference in activation between virgin and recycled negative electrode material. A module charged stepwise with 0.07C followed by 0.2C had the lowest share of H2 after two cycles, indicated best activation. However, a higher amount of H2 in the beginning of the activation process could possibly enhance the degree of activation during the following cycles. The method indicated that the module with recycled MH was better activated than the virgin MH. To improve the technique, repeated measurements to get better statistics should be done. Gas samples should be taken at dV/dt=0 in order to take samples at same SoC. The charge current should be adjusted so that the same C rate is always used. This would make the results easier to interpret. NiMH batteries Batteries Nickel-metal hydride Nickel hydroxide Metalhydride Gas evolution Oxygen Hydrogen Electochemistry Gas Chromatography NiMH-batterier Batterier Nickel-metalhydrid Nickelhydroxid Metalhydride Gasutveckling Syrgas Vätgas Elektrokemi Gaskromatografi Inorganic Chemistry Oorganisk kemi Chemical Engineering Kemiteknik Other Chemical Engineering Annan kemiteknik Materials Chemistry Materialkemi Analytical Chemistry Analytisk kemi Other Chemistry Topics Annan kemi Chemical Sciences Kemi Other Chemistry Topics Annan kemi
22	Vliv namáhání alkalických akumulátorů na jejich parametry / The influence of alcaline accumulators loading on their parameters Čech, Ondřej January 2009 (has links) This master's thesis deals with alkaline battery characteristics and it has special consideration of nickel-cadmium cells. There are three main experimental parts in this paper. First one is concerned with positive electrode materials properties and is aimed to investigate impact of magnesium ions formed into nickel hydroxide electrode structure. Second part deals with battery charging/discharging and response measurement tool design. National Instruments hardware PXI modules for data acquisition was used and program in LabView environment was made. Last one is concerned with nickel-cadmium cell properties changes during increased temperature stressing. Investigation of cell self-charge changes during lithium hydroxide addition into electrolyte was made.

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Characterization of the gas composition inside NiMH batteries during charge using GC-MS

Vliv namáhání alkalických akumulátorů na jejich parametry / The influence of alcaline accumulators loading on their parameters