表面包覆对非晶态CeMg_(12)合金电化学性能的影响(英文)  

Effects of Surface Coating on the Electrochemical Properties of Amorphous CeMg_(12) Composite

作　　者：陈如柑[1] 王新华[1] 葛红卫[1] 李寿权[1] 陈立新[1] 陈长聘[1] 

机构地区：[1]浙江大学,浙江杭州310027

出　　处：《稀有金属材料与工程》2009年第2期198-202,共5页Rare Metal Materials and Engineering

基　　金：National "863" Program Foundation (2006AA05Z129, 2006AA05Z143);National "973" Program Foundation (2007CB209706)

摘　　要：采用在CeMg12中添加镍粉球磨制备非晶态合金,并研究化学镀表面包覆Ni对其电化学性能的影响。结果表明,非晶态CeMg12具有很高的电化学放电容量,CeMg12+200%Ni(质量分数)球磨50h后复合电极材料电化学容量达到1209.6mAh/g,但是电化学循环稳定性较差,10次循环保持率为37.26%。通过化学镀镍进行表面包覆能明显提高合金的综合电化学性能。化学镀表面包覆Ni后,合金10个循环的保持率上升到69.67%;同时由于添加的Ni和包覆Ni的共同催化作用,合金高倍率性能也得到了相应的提高,HRD900由原来的54.2%提升到72.4%;但是由于化学镀过程中部分合金被氧化,使复合合金的最大放电容量略有下降。Amorphous CeMg12 was prepared by ball milled CeMg12 alloy with Ni powder. The effects of mechanical grinding and electroless deposition of nickel （EDN） on the electrochemical properties of CeMg12 composites have been studied systematically. Amorphous CeMg12 composites have a maximum discharge capacity of 1209.6 mAh/g, but their cycling stability is poor. The cycling retention rate of the electrode is 37.26% after 10 cycles. After EDN treatment, the cycling stability of CeMg12 composite is improved markedly, and the cycling retention rate increases to 63.67% after 10 cycles. The improvement of cycling retention rate can be attributed to compact nickel coating that prevents the inner Mg from further corrosion by alkali. The nickel coating also enhances the high rate discharge （HRD） property of the composite owning to the good electrochemical catalytic properties of Ni. As oxidation and corrosion is unavoidable during EDN treatment, the maximum discharge capacity decreases slightly for CeMg12 composite with EDN treatment.

关 键 词：贮氢合金 CeMg12 表面包覆 机械合金化 

分 类 号：TG132[一般工业技术—材料科学与工程]