La和Zn复合掺杂α-Ni(OH)_2电极材料的电化学性能

Electrochemical performance of α-nickel hydroxide codoped with La and Zn

采用尿素均相沉淀法制备出稀土La和Zn复合掺杂α-Ni(OH)2样品材料,同时采用XRD、EDS、IR和TG-DSC热分析技术对样品的微结构和组成进行了测试,并研究了样品作为MH-Ni电池正极活性材料的电化学性能。结果表明,稀土La和Zn复合掺杂α-Ni(OH)2材料具有较大的晶格间距,其含有更多的结构H2O分子,电极反应的电荷转移电阻较低;样品材料电极在以0.1C充放,终止电压1.0V的制度下,其放电比容量高达372.85mAh.g-1,同时放电中值电压较高并稳定于1.30V,1C下其放电比容量高达344.07mAh.g-1,充放电循环30次容量保持率为93.04%,显示出良好的较大倍率放电性能和循环可逆及结构稳定性能。

The rare metal La and Zn codoped α-nickel hydroxide was prepared by the urea precipitation method.The microstructure and composition of the sample were characterized by XRD,EDS,IR and TG-DSC.The electrochemical properties were also investigated when the sample codoped with La and Zn was made as the nickel electrode active material,and the MH-Ni battery was assembled.The results showed that the sample had a relatively larger interlayer distance and contained many structurally bonded water molecules,and the electrochemical reaction impedance was reduced.At 0.1 C charge-discharge rate,the discharge specific capacity reached 372.85 mAh·g-1 when the end potential was 1.0 V,simultaneously its discharge mediate potential was higher and maintained at 1.30 V.In addition,the discharge specific capacity of the sample could reach 344.07 mAh·g-1 at 1 C rate,and the capacity still remained 93.04% of the sample after 30 cycles.It demonstrated better high-rate discharge performance,and increased cycling and structural stability.