锌镍电池正极材料Ni(OH)_2表面覆钴的性能研究

Study on the characteristics of Ni(OH)_2 with surface coated cobalt hydroxide in Zn/Ni battery

为提升锌镍电池正极材料Ni(OH)_2的导电性,采用化学沉淀法在球形Ni(OH)_2颗粒表面覆钴。利用倍率充放电、扫描电子显微镜(SEM)、X射线衍射(XRD)、Tafel曲线、电化学阻抗谱等方法对合成材料进行表征与测试。结果表明:SEM显示钴能在Ni(OH)_2颗粒表面附着;Tafel曲线、电化学阻抗谱表明合成材料的耐蚀性、导电性均有优化。倍率充放电技术发现材料适宜的覆钴量为3%,镍电极以0.2充放电循环40次后循环保持率为83.2%。

In order to improve the conductivity of Ni(OH)2 as cathode material for Zn-Ni batteries,CoOOH was coated on the surface of spherical Ni(OH)2 particles by chemical precipitation method.The composites were characterized and tested by the charge-discharge technology,SEM,XRD,Tafel curves and electrochemical impedance spectroscopy.The SEMresults showed that the surface of Ni(OH)2 particles can be effectively adsorbed by CoOOH.Tafel curves and electrochemical impedance spectroscopy showed that the corrosion resistance and conductivity of the materials were optimized.The optimum cobalt content was 3%,and the retention rate of the nickel electrode was 83.2%after 40 cycles at 0.2.