Mg_2Ni+Ni型贮氢合金相形成及电化学性能

Phase formation and electrochemical performance of Mg_2Ni+Ni typed hydrogen storage alloy

采用压制烧结和随后机械合金化的方法制备了Mg2Ni+Ni型电极合金。研究了Al、Mn替代Mg后对Mg2Ni+Ni型合金相形成及电化学性能的影响。XRD测试显示:各合金在610～620℃经过5h烧结后的相结构大部分为Mg2Ni相,与Ni粉混合球磨72h后全部转变为均匀的非晶相。电化学性能测试结果表明:Al、Mn替代后再与Ni粉球磨后的合金,其放电容量、高倍率性能较Mg2Ni+Ni合金均有显著提高,其中Mg1.8Al0.15Mn0.05Ni+Ni合金的综合性能最佳。

Mg2Ni+Ni alloy powder was prepared by sintering and subsequently ball milling. Effects of the partial substitution of Al and Mn for Mg on the phase formation and electrochemical performance of Mg2Ni+Ni typed alloys were researched. The XRD results show that all alloy phases are mainly Mg2Ni after sintering for 5 h at 610-620 ℃, and their phases are uniform amorphous structure after mechanical grinding with Ni powder for 72 h. The electrochemical tests results show that the discharge capacity and highrate dischargeability of the alloys with the partial substitution of Al and Mn for Mg and the subsequently ball milling with Ni powder were significantly improved compared with that of Mg2Ni+Ni alloy. Over all, the Mg1.8Al0.15Mn0.05Ni+Ni alloy shows the best integrated properties.