合金组成对贮氢电极性能影响的研究

Influences of composition of Alloy on Properties of Hydrogen Storage Electrodes

本文研究了ＭＬＮｉ４Ｍ（ＭＬ：混合稀土金属，Ｍ＝Ｍｎ、Ｃｏ、Ａｌ、Ｃｒ、Ｆｅ、Ｓｉ），ＭＬＮｉ（４－Ｘ）ＭｎＡｌＸ（Ｘ＝０～０．５）及ＭＬＮｉ（３．５）ＭｎＣｏ（０．４）ＡＬ（０．１）等几种不同组成贮氢合金的电化学性能，结果表明含有少量Ｍｎ、Ｃｏ、Ａｌ的贮氢电极具有较好的综合性能。扫描电镜（ＳＥＭ）观察认为，贮氢合金在充放电过程中的不断粉化和氧化是贮氢电极失效的主要原因。贮氢合金组成不同，氢扩散系数也不同，具有较大氢扩散系数的电极，其快速放电能力较强，放电过电位较小。

The influenes of replacing elements (Mn、 Co、 Si、 Fe、 Cr) on the electrochemical characteristics of mischmetal hydrogen storage alloys were studied. The experimental results have shown that the metal hydride(MH) electrodes containing Mn、 Co、 AL、 displayed better electro-chmical performances. The SEM observation considered that the pulverization and oxidation of hydrogen storage alloys during charge discharge cycles was a important factor of the degradation of MH electrodes. The diffusion coefficient of hydrogen in alloy was measured by potential step method. It was found that the diffusion coefficient was effected by composition of hydrogen storage alloys.