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.
出处
《功能材料》
EI
CAS
CSCD
北大核心
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)
关键词
富镧贮氢合金
铜
晶体结构
电化学性能
La-rich hydrogen storage alloy
copper
crystal structure
electrochemical properties