贮氢电极合金Ml（NiMnTi）4.2Co0.8—XFex（x=0—0.8）的电化学性能

摘要:

详细地研究了Ｍｌ（ＮｉＭｎＴｉ）４．２Ｃｏ０．８－ｘＦｅｘ（ｘ＝０－０．８）合金的电化学性能。试验发现，随着Ｆｅ含量ｘ从０增加至０．，合金的活化性能得到改善，但最大放电容量从３０２ｍＡｈ／ｇ逐渐降低到２８０ｍＡｈ／ｇ，高倍率放电性能从７８．５％缓慢降至７２．５％；当Ｆｅ含量ｘ≤０．４时，合金的自放电率与高Ｃｏ合金（ｘ＝０）相比有所降低，但当Ｆｅ含量ｘ超过０．４后，合金的自放电率较高Ｃｏ合金有所上升

Abstract:

The electrochemical performances of the Ml(NiMnTi)_(4.2)Co_(0.8-x)Fe_x hydrogen storage alloys have been investigated.The results show that as the Fe content (atomic ratio) increases to 0.8 from 0, the activation behavior is improved, but the highestcapacity decreases to 280 mAh/g from 302 mAh/g and the high-rate-dischargeability is degraded lightly. When Fe content (x) is lessthan 0.4, the self~discharge rate is lower than that of high-Co alloy (x=0), however, as x>0. 4, the self-discharge rate is higherthan that of high-Co alloy. It has been found that when Fe content increases, the cycling stability decreases slightly.