贮氢电极合金微结构和电化学性能的影响
(浙江大学 材料科学与工程系， 杭州 310027)
摘 要: 研究了铸态及经加热温度为1273～1373K 、保温时间8h和水冷处理后AB5型MlNi3.60Co0.85Mn0.40Al0.15贮氢电极合金的微结构和电化学性能 。结果表明：铸态合金 的显微组织为典型的树枝晶结构，经1273K处理后合金的显微组织仍为树枝晶，但树枝结构不明显，经1373K处理后合金的显微组织为柱状晶；与铸态合金相比，经1273K处理后合金的 活化性能降低，电化学容量和高倍率放电性能基本保持不变，循环寿命改善；经1373K处理 的合金活化性能降低，电化学容量明显减小，高倍率放电性能降低，循环寿命显著改善 。热处理引起合金电化学性能的变化与合金的微结构的改变有关。
关键字: 贮氢电极合金； 热处理； 微结构； 电化学性能
and electrochemical properties of AB5 type
MlNi 3.60Co 0.85Mn 0.40Al 0.15 hydide electrode alloy
（Department of Materials Science and Engineering，
Zhejiang University, Hangzhou 310027， P.R.China）
Abstract: The effects of heat treatment wi th different temperature on the microstructure and electrochemical properties of AB5 type MlNi 3.60 Co 0.85Mn 0.40Al 0.15 hydride electrode alloy were studied systematically. The results show that，the microstructure of as-cast alloy is typical dendrite and that of the alloy by heat treatment with 1273K is unconspicuous dendrite，and after bein g hea t treatment with 1373K，the microstructure of the alloy changes to columnar cry stal. As compared with as-cast alloy，after being heat-treated by 1273K，the activation characteristics decrease and the electrochemical stability impro ves，while both electrochemical capacity and high-rate dischargeability almost uncha n ge; after being heat-treated by 1373K，the activation characteristics decr ease a ppreciably，the electrochemical capacity decreases drastically，the high-rate di schargeability decrease slightly，and the electrochemical stability is improved mar kedly. The change of electrochemical properties of the alloy heat-treated at di fferent temperatures is related to the microstructure of the alloy.
Key words: hydride electrode alloy； heat treatment; mic rostructure; electrochemical properties
