(1. 洛阳工学院 材料工程系, 洛阳 471039;
2. 四川大学 金属材料系, 成都 610065)
摘 要: 研究了化学配比x 对贮氢合金Ml(Ni0.71 Co0.15 Al0.06 Mn0.08)x(4.6≤x ≤5.2)的结构、 组织、 电化学性能和 pcT 特性的影响。 结果表明, 随着x 增大非化学计量比合金点阵常数 a 值减小, c 值增大, 单胞体积减小, 当x =5.2时 c/a 达到最大值。 x =5.0的化学计量比合金具有最小的点阵常数和单胞体积。放电容量、 充放电循环稳定性和 pcT 曲线平台压均随着x 增大而提高, 当x =5.2时达到最大放电容量和最佳循环稳定性。
关键字: 贮氢合金; 金属氢化物电极;稀土合金; 电化学性能
(1. Department of Material Engineering,Luoyang Institute of Technology, Luoyang 471039, P.R.China;
2. Department of Metal Materials, Sichuan University, Chengdu 610065, P.R.China)
Abstract:Effect of stoichiometry on phase structures, electrochemical properties and pcT characteristics of Ml(Ni0.71Co0.15 Al0.06Mn0.08)x (Ml=lanthanumrich michmetal, 4.6≤ x ≤5.2) alloys have been investigated. The lattice constants a, c , and cell volumes of nonstoichiometric alloys are bigger than those of the stoichiometric alloy. The value of a decreases, the values of c andcell volume increase with increasing value of x except for those of the stoichiometric alloy. The plateau pressure of pcT curve, discharge capacities and cycling stability all increase with increasing value of x . The alloy with x =5.2 hasthehighest discharge capacity and the best cycling stability among the studied alloys.
Key words: hydrogen storage alloy; metal hydride electrode; rare earth alloy; electrochemical property