稀土贮氢合金 RE(NiCoMnAl)_5 的相结构与电容量关系

Study of phase constituent and electrochemical properties of RE(NiCoMnAl) 5 hydrogen storage alloys

研究了ＡＢ５型稀土贮氢合金ＲＥ（ＮｉＣｏＭｎＡｌ）５在Ａ侧组分改变下的相结构与电化学性能之间的关系。结果表明：在Ａ侧Ｎｄ（或Ｐｒ）＝０．２时Ｌａ０．８ＲＥ０．２（ＮｉＣｏＭｎＡｌ）５合金的放电容量达最高值（３２０ｍＡｈ／ｇ）；Ｌａ１－ｘＮｄｘ（ＮｉＣｏＭｎＡｌ）５合金的晶胞体积随组分ｘ呈线性减小，少量的Ｎｄ替换对放电容量有良好的影响；退火处理改善了合金的放电容量，但起始活化较慢，可能与表面氧化物的生成有关；快凝条件下晶体织构生长及一次枝晶细化，因而有利于电化学综合性能的提高。

The phase constituents and capacity of RE(NiCoMnAl) 5 hydrogen storage alloys with different compositions of rare earth compounds (RE=La 1-x-y-z Nd xPr yCe z) were studied.The results showed that all the La,Nd,Pr and Ce had effect on the electrode performance,and the discharge capacity reached max value (320mAh/g) at Nd(or Pr)=0.2;the cell volume was a linear function to the Nd content x in La 1-x Nd xB 5;the capacity had been improved through annealing procedure,but iniatial active velocity is slow due to the formation of the rare earth oxide.The texture growth and the formation of a fine primary dendrite can be obtained due to rapid solidification,and hence,the electrochemical characteristics were increased.