熔体旋淬Ml(NiCoMnAl)_5贮氢合金的微结构与电化学行为  

Microstructure and electrochemical behaviors of melt-spinning alloy Ml(NiCoMnAl)_5

作　　者：文明芬[1] 佟敏[1] 陈廉[1] 吴锋 陈德敏[1] 单忠强 马荣骏[3] 翟玉春[4] 

机构地区：[1]中国科学院金属研究所,沈阳110015 [2]国家高技术新型储能材料工程开发中心,中山528437 [3]长沙矿冶研究院,长沙410012 [4]东北大学材料与冶金学院,沈阳110006

出　　处：《中国有色金属学报》2001年第1期84-90,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家"八六三"计划资助!项目 (715 -0 0 4-0 2 33)

摘　　要：研究了熔体旋淬和常规熔铸Ml(NiCoMnAl) 5贮氢合金的微结构和电化学行为。SEM和XRD分析表明 ,熔体旋淬合金由细小的柱状晶组成 ,它们的晶体结构与铸态一样 ,都为CaCu5型六方晶体结构。电化学测试表明 ,旋淬态合金电极初始容量较高 (>2 10mA·h/ g) ,经 1～ 2次循环就可达到最大放电容量。旋淬速度为 10m/s的合金电极的放电容量 (2 94mA·h/g)稍高于铸态合金电极的容量 ,所有旋淬态合金电极充放电循环稳定性皆优于铸态合金。在 6 0 0mA/ g电流质量密度下 ,旋淬速度为 10m/s的合金电极具有较好的高倍率充放电能力 ,但随着循环次数的增加 ,其容量稳定性稍次于旋淬速度为 2 5m/s和 40m/s的合金电极。The microstructure and electrochemical behaviors of Ml(NiCoMnAl) 5 alloys prepared by both the melt spinning method and the conventional induction melting were investigated. SEM and XRD analysis show that melt spinning alloys are of columnar microstructure which belong to the CaCu 5 type hexagonal crystal structure as same as as cast alloy. The electrochemical measurements show that the initial capacities of melt spinning alloy electrodes are all above 210 mA·h/g, reaching their maximum capacities after the second charge discharge cycles. The maximum capacity (294?mA·h/g) of melt spinning (10?m/s) alloy electrodes is the same as that of as cast alloy electrode, the stability of charge discharge cycles of all melt spinning alloy electrodes is better than that of the as cast alloy electrodes. When charged at 600?mA/g, the melt spinning (10?m/s) alloy electrode has better high rate discharge capability; but with the cycle number increasing, the cycle stability is less than those electrodes of melt spinning rate of 25?m/s and 40?m/s. [

关 键 词：熔体旋淬 贮氢合金电极 电化学行为 柱晶组织 微结构 NIMH电池 

分 类 号：TG139.7[一般工业技术—材料科学与工程] TM912.1[金属学及工艺—合金]