Study on the processing of La-Mg-Ni hydrogen storage alloys prepared by SPS

Spark plasma sintering (SPS) proces was used in this study to prepare the La-Mg-Ni hydrogen storage alloys in order to avoid the drawbacks of high temperature and long time of other processes and to improve the repeatability. La0.7Mg0.3Ni2.5 Co-0.5 alloy was used as an example to determine the best processing parameters. The results indicate that the alloy sintered at 800 degrees C is multiphase structure and composed of the (La, Mg)Ni-3 phase, (La, Mg)(2)Ni-7 phase, Mg2Ni phase and little Co2Mg phase. The alloy has the maximum discharge capacity up to 359 mAh/g, and the best characteristic of discharge potential at the same time.