镍氢电池的循环性能与活性物质微结构的研究

与循环试验大致同步, 用静态(初态和终态)或准动态(增加若干个中间态)的模式对MH/H电池循环性能、电极(包括负极和正极)材料的微结构进行了X射线衍射(XRD)研究, 发现循环性能衰减与正极材料β-Ni(OH)₂的点阵参数、平均晶粒尺度、微应变和总的层错几率均随循环周期增加而减小以及负极材料中腐蚀产物A(OH)₃和B相出现和增加有一定的对应关系, 发现MH/Ni 电池循环性能的衰减是正极材料和负极材料的结构和微结构随着循环次数的增加发生明显变化, 恶化了正负极材料的电化学性能, 同时消耗和恶化了电解液的综合结果. 为了提高电池的循环性能, 采用不同正极材料的添加剂. 结果表明, CaF₂和Lu₂O₃有明显的效果, 其中CaF₂效果最好, 并有广泛的实用性.

Research of Circulation Properties and Microstructure in Active Substances for MH/Ni Battery

The circulation properties and microstructure in active substances for MH/Ni batteries have been researched. It was found that corresponding relationship among attenuation of circulation property and decreasing of lattice parameters, average grain size, micro-strain, total fault probability in β-Ni(OH)₂ with increasing of circulation cycles and producing and increasing of corrosive products (A(OH)₃ and B phases) in AB₅ with increasing of circulation cycles. Attenuation mechanics of circulation properties for MH/Ni battery has been discussed. Circulation properties attenuation is the synthesized results of obvious changes of crystal structure and microstructure in positive and negative electrode materials during circulation cycle experiment, especially corrosion products are separated out in AB₅ materials, which deteriorating electrochemical properties of β-Ni(OH)₂ and AB₅ materials and which depleting and deteriorating electrolyte at the same times. For elevating circulation property of this battery some additives of positive electrode were used. The research results show that effects of CaF₂ and Lu₂O₃ are better. Specially the effect of CaF₂ is the best, so it has broad practicability.