Formula Optimization Of Low Cost And Non-annealed MmNi_4.36-xAl_0.54Cu_x Hydrogen Storage Alloys

In this thesis, MmNi4.36-xAl0.54Cux and MmNi3.74-xAl0.49Cux AB5-type hydrogen storage alloys were confirmed as the research objects on the basis of previous work and world market price of raw materials. The electrochemical performances were studied, including the maximum stable discharge capacity, cycle life, charge retention ratio, high rate charge-discharge abilities, high-temperature and low-temperature discharge capacity. The results showed that hydrogen storage alloys with8%wt copper had better high-temperature and low-temperature discharge capacity, alloys with5%wt copper had higher charge retention ratio, and alloys with9%wt copper had better high rate charge-discharge abilities. From the XRD and SEM analysis, it showed that the alloys were mainly composed of LaNi5phase, and the crystals were well. The diffusing channel of H dissociating from MH changed with different expansion ratio of metallic crystal at different temperatures. The discharge capacity changed with different copper content and the aim formulas were found by finding the optimal copper content.