Electroless nickel plating, electroless copper plating and electroless Cu-Ni composite plating were carried out on AB3-type hydrogen storage alloy LaMg2Ni6Mn3,respectively. The maximum discharge capacity is increased from 319 mA.h/g to 390 mA.h/g and the decline rate of discharge capacity is decreased from 20％ to 1％ after electroless Cu-Ni alloy composite plating. The results of X-ray diffraction analysis showed that the formation of CuNi4O and Mg2Ni3O phases is the factor of enlarging the maximum discharge capacity and enhancing the cycling stability. SEM images indicated that, after the electroless Cu-Ni composite plating, a coating with spherical grains was deposited on the surface of hydrogen storage alloy, preventing oxidation and pulverization during charge/discharge process of the hydrogen storage alloy and improving the comprehensive electrochemical properties of the hydrogen storage alloy.%分别对AB3型贮氢合金(LaMg2Ni6Mn3)进行化学镀铜、化学镀镍及复合化学镀铜--镍合金.化学镀铜--镍合金后,最大放电容量由319 mA-h/g增大到390 mA-h/g,合金的容量衰减率从20%降至1%.X射线衍射结果显示,CuNi4O相和Mg2Ni3O相是导致合金最大放电容量增大以及循环稳定性增强的因素.扫描电镜结果表明,复合化学镀后合金表面出现球状镀层,能够阻止贮氢合金在充放电过程中的氧化-粉化脱落,有助于改善复合化学镀后合金的综合电化学性能.
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