中文摘要：

为了改善La-Mg-Ni基贮氢合金的循环稳定性和综合电化学性能,研究了电镀镍-钴合金对La0.88Mg0.12Ni2.95Mn0.10Co0.55Al0.10贮氢合金粉末表面形貌和电极电化学性能的影响.FESEM表明,电镀处理后合金粉末表面沉积了球状的镍-钴合金颗粒.电化学性能测试表明,贮氢合金电极的放电容量、高倍率放电性能和循环稳定性均得到了显著改善.200周循环时合金电极的容量保持率从未处理合金电极的60%提高到镀覆镍-钴合金的80%,在放电电流密度1080mA/g下的高倍率放电性能提高了23%.线性极化曲线和电化学阻抗分析结果显示,包覆镍-钴合金后贮氢合金电极表面的电荷转移速率加快,电催化活性提高.

英文摘要：

In order to improve cycling stability and overall electrochemical properties of La-Mg-Ni-based hydrogen storage alloys,an electroplating treatment was applied on La0.88Mg0.12Ni2.95Mn0.10Co0.55Al0.10 alloy powders.The effect of cobalt-nickel coating on the morphological and electrochemical properties was studied.FESEM results show that spherical nickel-cobalt alloy particles are deposited on the surface of the alloys.Electrochemical tests indicate that the maximum discharge capacity,the cycling stability and the high rate dischargeability（HRD） are remarkably improved.After 200 charge/discharge cycles,the capacity retention rate increases from 60%（uncoated） to 80%（nickel-cobalt coated）.The HRD at 1080mA/g rises by 23% for the nickel-cobalt coated alloy electrodes.Linear polarization and Electrochemical Impedance Spectroscope（EIS） results reveal that the surface of alloy electrodes with cobalt-nickel coatings is more catalytic for the electrochemical charge transfer reactions.