不同类型MH/Ni电池自放电性能研究

Study of self-discharge performance of different type of Ni-MH battery

从电解液组成、正极添加剂和隔膜3个方面入手研究了改善金属氢化物/镍(MH/Ni)电池自放电性能的措施.结果表明,采用丙烯酸接枝或磺化处理的PP隔膜以及采用NaOH电解液代替KOH电解液均可以有效降低电池的自放电率;而正极中加入高温添加剂无明显效果.另一方面,通过降低MH/Ni电池的自放电率可以减缓储存期间电池开路电压下降的速率,延缓CoOOH还原反应的发生,从而在一定程度上降低其容量不可逆衰减率.

The improvement of self-discharge performance of nickel-metal-hydride （Ni-MH） battery is studied from electrolyte, additives of the positive electrode and separator. The results show that the self-discharge rate of the battery can be significantly lowered by using a NaOH electrolyte instead of a KOH electrolyte and using PP separators with acrylic acid grafting or sulfonating treatment separately. Thus, the open-cireuit voltage of the battery can fall more slowly and the reduction of CoOOH can be suspended during storage, which results in a decrease of irreversible capacity loss of the battery. On the other hand, high-temporature additives of the positive electrode have no benefit to self-discharge performance of the battery.