貯氫電極合金微結(jié)構(gòu)和電化學性能的影響
(浙江大學 材料科學與工程系， 杭州 310027)
摘 要: 研究了鑄態(tài)及經(jīng)加熱溫度為1273～1373K 、保溫時間8h和水冷處理后AB5型MlNi3.60Co0.85Mn0.40Al0.15貯氫電極合金的微結(jié)構(gòu)和電化學性能 。結(jié)果表明：鑄態(tài)合金 的顯微組織為典型的樹枝晶結(jié)構(gòu)，經(jīng)1273K處理后合金的顯微組織仍為樹枝晶，但樹枝結(jié)構(gòu)不明顯，經(jīng)1373K處理后合金的顯微組織為柱狀晶；與鑄態(tài)合金相比，經(jīng)1273K處理后合金的 活化性能降低，電化學容量和高倍率放電性能基本保持不變，循環(huán)壽命改善；經(jīng)1373K處理 的合金活化性能降低，電化學容量明顯減小，高倍率放電性能降低，循環(huán)壽命顯著改善 。熱處理引起合金電化學性能的變化與合金的微結(jié)構(gòu)的改變有關。
關鍵字: 貯氫電極合金； 熱處理； 微結(jié)構(gòu)； 電化學性能
and electrochemical properties of AB5 type
MlNi 3.60Co 0.85Mn 0.40Al 0.15 hydide electrode alloy
ZHU Yun-feng, LI Shou-quan, CHEN Chang-pin
（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
