磁热处理对La-Mg-Ni-Cu合金相结构与电化学性能的影响  

Influence of Magnetic-Heat Treatment on Phase Structure and Electrochemical Properties of La-Mg-Ni-Cu Alloys

作　　者：赵显久[1] 李谦[1] 刘静[1] 周国治[1,2] 林根文[1] 

机构地区：[1]上海大学,上海200072 [2]北京科技大学,北京100083

出　　处：《稀有金属材料与工程》2009年第5期857-861,共5页Rare Metal Materials and Engineering

基　　金：上海市科委西部开发科技合作项目(065258036);上海市青年科技启明星计划(06QA14021);全国博士学位论文作者专项资助项目(200746)

摘　　要：考察了La0.67Mg0.33Ni2.5Cu0.5合金分别在铸态、热处理后及磁热处理后3种状态下的相结构及其电化学性能。并通过XRD分析合金物相组成及SEM观察合金组织形貌,研究了Cu部分取代Ni以及有无外加磁场下热处理对合金相结构与电化学性能的作用规律。结果表明,La0.67Mg0.33Ni2.5Cu0.5铸态合金经过50次循环后,放电容量保持率从64.40%提高到72.44%;经磁热处理的La0.67Mg0.33Ni2.5Cu0.5合金最大放电容量为328.2mAh/g,较常规热处理合金的容量提高了31.51%,50次循环后的容量保持率为75.89%。其放电平台更为宽广且平坦;极限电流显著增大,氢在合金体相中的扩散速度加快。The phase structure and electrochemical properties of La0.67Mg0.33Ni2.5Cu0.5 alloys as cast and treated by heat treatment and magnetic-heat treatment were studied in this paper. The influence of the heat treatment and magnetic-heat treatment as well as Ni substituted partly with Cu on the phase structure and electrochemical properties of La-Mg-Ni-Cu alloys were investigated by XRD and SEM analysis. The results show that the retention of discharge capacity of as-cast La0.67Mg0.33Ni2.5Cu0.5 alloy is increased to 72.44% from 64.40% after 50 cycles. The maximum discharge capacity of La0.67Mg0.33Ni2.5Cu0.5 alloy after magnetic-heat treatment is 328.2mAh/g, which is 31.51% larger than that of La0.67Mg0.33Ni2.5Cu0.5 alloy after heat treatment. Its retention of discharge capacity is 75.89% after 50 cycles. The characteristic of discharge voltage platform is much flatter and longer, the limit current density is increased and the diffusion speed of hydrogen in the alloys increases.

关 键 词：贮氢合金 AB3型电极合金 磁热处理 电化学性能 

分 类 号：TG139.7[一般工业技术—材料科学与工程]