低成本富镧贮氢合金的相结构及其电化学性能  

Phase structure and electrochemical properties of low cost La-rich hydrogen storage alloy

作　　者：苏振华[1] 刘开宇[1,2] 张思方[1] 段浩[1] 

机构地区：[1]中南大学化学化工学院,湖南长沙410083 [2]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《功能材料》2007年第A04期1612-1614,共3页Journal of Functional Materials

基　　金：基金项目：国家留学基金资助项目（[2003]3038）

摘　　要：采用感应熔炼法制备低成本富镧贮氢合金MLNi4.0-xCo0.4Mn0.3Al0.3Cux.通过X射线衍射（XRD）、交流阻抗和恒电流充放电法等手段对合金性能进行表征。结果表明：Cu部分取代Ni后，合金仍保持单相CaCu5结构，随着X的增加，合金晶格参数a值和晶胞体积减小，c值和c／a值增大：当x=0．2时，合金电极最高放电容量为327．1mAh/g铜的添加能降低舍金的显微组织硬度，提高合金电极的循环稳定性，经200次循环后的电极容量保持率（C200／Cmax）均在83％以上（X=0．2）；高倍率放电性能（HRD）有所下降，但x=0．4时，HRD300仍达到89．6％。A low cost La-rich hydrogen storage alloy （MLNi4.0-xCo0.4Mn0.3A10.3Cux） were prepared by induction-melting. Properties of alloy was characterized by XRD,EIS and constant charge ＆ discharge current experiments. Results reveal that the phase structures of alloy are only composed of CaCu5 type phase, with increasing x, the values of lattice parameters a and cell volume decrease, c and c/a increase gradually. The electrochemical tests show that when x=0.2, the largest discharge capacity is 327.1mAh/g. The cycle stability increase obviously with the increase of Cu, the rates of capacity retention of the alloys after 200 charge/discharge cycles are about 83%; HRD of alloy decreases gradually, but also it reached to the HRD300（89.6%） when x=0.4.

关 键 词：富镧贮氢合金 铜 晶体结构 电化学性能 

分 类 号：TG139.7[一般工业技术—材料科学与工程]