Cycle stability of La_0.7Mg_0.3Ni_2.55-xCo_0.45Cu_x (x=0-0.4) electrode alloys

来源期刊：中国有色金属学报(英文版)2007年第4期

论文作者：张羊换 赵栋梁 李保卫 任慧平 董小平 王新林

文章页码：816 - 816

Key words：La-Mg-Ni alloy; La_0.7Mg_0.3Ni_2.55-xCo_0.45Cu_x alloy; Ni; microstructures; cycle stability

Abstract: The La_0.7Mg_0.3Ni_2.55-xCo_0.45Cu_x (x=0, 0.1, 0.2, 0.3, 0.4) electrode alloys were prepared by casting and rapid quenching. Ni in the alloy was partially substituted by Cu in order to improve the cycle stability of La-Mg-Ni system (PuNi₃-type) hydrogen storage alloy. The effects of substituting Ni with Cu on the microstructures and cycle stability of the alloys were investigated in detail. The results obtained by XRD, SEM and TEM show that the substitution of Cu for Ni is favourable for the formation of an amorphous in the as-quenched alloy, and this leads to an obvious refinement of the as-quenched alloy grains and a growth of the lattice constants and cell volumes of the as-cast and quenched alloys. The results obtained by the electrochemical measurement indicate that the cycle stability of the alloys significantly rises with the incremental variety of Cu content. When Cu content changes from 0 to 0.4, the cycle lives of the as-cast and quenched (30 m/s) alloys are enhanced from 72 to 88 cycles and from 100 to 121 cycles, respectively.

基金信息：the National Natural Science Foundation of China
the Key Technologies Research and Development Program of Inner Mongolia
the Higher Education Science Research Program of Inner Mongolia, China