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.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
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)
关键词
贮氢合金
AB3型电极合金
磁热处理
电化学性能
hydrogen storage alloys
AB3-type electrode alloy
magnetic-heat treatment
electrochemical properties
