MH-Ni电池降低内压延长寿命的方法

分析了ＭＨ－Ｎｉ电池内压产生的原因。为了降低ＭＨ－Ｎｉ电池的内压提高寿命，分别通过ＭＨ负极用粘合剂以及合金粉制作工艺两个方面进行研究，结果表明：不同种类的粘合剂对电池内压有较大影响，通过对粘合剂的作用机理进行分析，认为亲水性粘合剂与憎水性粘合剂配合使用效果较好，实验结果表明负极采用０．５％ＨＥＣ和１％ＰＴＦＥ配合使用能有效地降低电池１Ｃ过充电时电池的内压；热处理合金与非热处理合金粉对电池内压及循环寿命影响也较大，通过对比ＰＣＴ曲线发现，合金粉经过热处理，曲线平台变宽，实验结果表明，采用热处理合金粉不仅能显著地降低电池内压，还能提高电池１Ｃ充放电循环寿命。通过上述方法制作的ＡＡ型电池１Ｃ充１２０ｍｉｎ电池内压小于０．８ＭＰａ。

Method of reducing internal pressure of Ni MH battery and increasing cycle life

The causes of producing internal pressure of Ni MH battery were analyzed in this paper. In order to reduce internal pressure of Ni MH battery and increase cycle life, binders for MH clectrode and manufacture process of hydrogen storage alloy powders were studied. Different kinds of binder for MH electrode had a distinct influence on inner pressure of battery. Through analyzing the mechanism of binders it is found that the combination of hydrophilic binder and hydrophobic binder for MH electrode had a good effect on the performance of battery. The experimental results show that binders of 0.5% HEC and 1% PTFE for MH electrode can decrease inner pressure of Ni MH battery when it is overcharged at 1C. Differences of inner pressure and cycle life of Ni MH battery were shown between heat treated powders and as cast powders for MH electrode. Making a comparison of PCT curves between heat treated powders and as cast powders, the curve platform of heat treated powders was wider than that of as cast powders. The experimental results show that heat treated powders for MH electrode can not only conspicuously decrease inner pressure but also increase cycle life of Ni MH battery. The inner pressure of AA size can be lower than 0.8MPa at 1C for 120min.