| This dissertation is focused on the research of the hydrogen storage alloy, and the emphasis of my work is mainly about the preparation and research of magnesium based alloy.As the hydrogen storage system and the negative-electrode material, the hydrogen storage alloy has been widely used. The alloy of AB5 type is applied to the battery industry for its mature research and technique, but its discharging capacity is closed to the theory limitation.Mg2Ni-type alloys are promising materials due to their high hydrogen storage capacity(up to 3.6wt%), low material cost, rich mineral sources and light weight. It has become an important research point.Upon the application to the industry, I do some work around the cycle mechanism of the AB5-type hydrogen storage alloys and the alloys doped with CoO, which are used as negative-electrode material. It was found that the decay in capacity of AB5-type hydrogen storage alloys was ascribe to the cracking and the corrosion. It had an Co layer because of the CoO addition, and it was helpful to prohibition to the cracking and corrosion.In this work, The alloy Mg1.8Al0.2Ni1-xMnx was synthesized by the Diffusion Method, and changed its surface state by ball-milling treatment. We also studied the preparation technology and the alloy performance. The results got from the experiment showed that sintering for 6h at 550℃under Argon atmosphere is the moderate condition for producing Mg3AlNi2 phase alloys. The result from XRD showed that the alloys were mostly composed Mg3AlNi2 with cubic structure. And the addition of Al was useful to the alloys cycle life and the addition of Mn was useful to improve the activation performance and the capacity. The alloys synthesized by DM has the highest capacity of about 407mAh/g after ten cycles activation, but the capacity of the alloys ball milled can got up to 570mAh/g after three cycles activation. The longer ball-milling time properly ,the better performance.The mechanical alloying(MA) process has recently emerged as a novel technique for producing alloy powders whose structure are nanocrystalline or amorphous. This dissertation synthesized Mg2Ni-type alloy- Mg1.8Al0.2Ni0.7Mn0.3 by MA. We found out the moderate synthesis technology, and studied its structure and electrochemical performance. It was suggested that the alloy Mg1.8Al0.2Ni0.7Mn0.3 has the nanocrystalline or amorphous structure. The alloy Mg1.8Al0.2Ni0.7Mn0.3 ball-milled for 100h had the highest capacity of about 625mAh/g(50mAh/g,-1.0vs Ni(OH)2/NiOOH) without any activation. The results from the experiment suggested that MA can get the capacity up and improve its other electrochemical performance of the alloys ,and charging-discharging efficiency is higher than that prepared by DM, but its cycle performance didn't get better , and it needs further work to do.
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