贮氢合金表面处理改善Ni/MH电池1C充放电性能

研究了贮氨合金两种表面化学处理方法对MH电极活化性能及Ni／MH电池IC充放电性能的影响：第一种处理方法是贮氢合金在6th。l·L－’KOH溶液中80T处理sh，第二种处理方法是在含有0．04mol·L－‘KBH4的6mol·L’‘KOH溶液中80t处理sh．通过MH电极的放电容量、充放电过程中电极极化和电化学阻抗谱测试评价了上述化学处理对电极活化性能的影响．电子探针表面分析表明化学处理后贮氢合金表面由于铝元素的优先溶解形成一层具有较高电催化活性的富镍表面层，它是改善电极活化性能的主要原因·以处理的贮氨合金为负极材料的Ni／MH电池具有较高IC充放电循环寿命和1．ZV以上放电容量．

Surface Treatments of Hydrogen Storage Alloy Improve Charge-discharge Performances of Ni/MH Battery

The hydrogen storage alloys were treated by two kinds of surface cl1emical treatments to improve the activation property of MH electrodes and 1C charge/discharge characteristics of Ni/MH batteries. The first was the alloys were immersed in 6 mol?L-1 KOH solution at 80℃ for 8h, the second was the alloys were immersed in 6 mol?L-1 KOH solution containing 0.04 mol?L-1 KBH4 at 80 ℃ for 8h. The effects of chemical treatments on performances of MH electrodes were evaluated by discharge capacity, polarization and electrochemical impedance. Electron probe analyses for the surface composition of the alloy indicated that a Ni-rich surface layer with high electrochemical activity was formed on the alloy surface by preferential dissolution of Al.Ni/MH batteries employing treated alloys as negative electrode material have long cyclic life at 1Cand higher capacity over 1.2V.