低温对储氢合金及电解液性能的影响

选用镍氢动力电池负极材料储氢合金为研究对象, 观察在常温、低温条件下循环后储氢合金电极表面各元素分布、粒度变化, 并提出电解液电导率变化及隔膜失效也是镍氢电池早期失效的一个重要原因。实验结果表明, 经低温循环失效后, 合金表面一些活泼元素在电解液中发生腐蚀反应, 如Co, La, Mn, Al等, 其中Mn、Al溶解损失严重。合金原粉颗粒的平均大小为23.6988 μm, 而经25 ℃、-20 ℃下循环实验而失效的电池负极合金粉颗粒的平均粒径分别为4.1874、4.5151 μm, 说明负极已发生严重的粉化现象。

Effects of Low Temperature on Performance of Hydrogen-storage Alloys and Electrolyte

The hydrogen-storage alloys of Nickel/Metal hydride batteries for electric vehicle were used as the experimental materials. The elements distribution and granularity distribution of the active materials for negative electrodes were studied under the conditions of normal temperature and low temperature. The change of the electrical conductivity of electrolyte and the deterioration of diaphragm were considered to result in the degradation of Ni/MH batteries. The results showed that some active elements on the alloys were solved in the electrolyte, such as Co, La, Mn and Al. The significant loss of Mn and Al could be observed. The average size of the alloy particles of fresh battery is 23.6988 μm, while that of the batteries spent at 25℃ and -20℃ are 4.1874 μm and 4.5151 μm respectively, indicating a serious pulverization of the negative electrode.