提高混合稀土贮氢合金活化性能研究

Study on the improvement of the rising characteristics of MmNi 5 based hydrogen absorbing alloys

为提高混合稀土镍基贮氢合金的活化性能，研究了贮氢合金Ｍｍ（ＮｉＣｏＭｎＡｌ）５－ｘＭｘ（Ｍ为添加的第五元素）。充放电试验结果表明，该贮氢合金的比容量约为２８５ｍＡｈ／ｇ，初期活化性能优于普通ＡＢ５型贮氢合金（经７次～８次循环可达容量最大值）。线性极化法测得的交换电流密度Ｊ０大于普通ＡＢ５型贮氢合金，这是其活化性能较好的原因之一。微电极循环伏安法测得的循环寿命亦明显优于普通ＡＢ５型贮氢合金。少量第五元素Ｍ的加入，可以有效提高贮氢合金的活化性能和循环寿命，具有良好的工业应用前景。

To improve the rising characteristics of MmNi 5 based hydrogen absorbing alloys,Mm(NiCo MnAl) 5 x M x (M is the fifth kind of substituted element)was studied.It had better rising characteristics than general AB 5 alloys with a specific capacity of 285mAh/g after 7 to 8 cycles.The exchange current density J 0 obtained by linear polarization was higher than that of Mm(NiCoMnAl) 5,attributed to the better rising characteristics.The cycle life obtained by microelectrode voltammetry was longer than that of Mm(NiCo MnAl ) 5.Adding little the fifth element,both the rising characteristics and cycle life could be improved effectively,showing a bright prospect of widely industrial use.