Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 9 No. 3 September 1999|
（1. Department of Physics;
2. Department of Materials Science and Engineering,Zhejiang University, Hangzhou 310027, P. R. China）
Abstract:The influences of Ca-substitution for Ml and surface treatment on electrochemical performances of Ml1.0-xCaxNi4.0Co0.6Al0.4 hydrogen storage alloy electrode were investigated. Ca-substitution withx<0.2 for Ml could improve its discharge capacity, but Ca-substitution withx>0.2 could decrease the capacity. It was also found that Ca-substitution deteriorates the electrocatalytic activity, high-rate dischargeability and cycling durability of the alloy electrode. In order to improve these properties of Ml1.0-xCaxNi4.0Co0.6Al0.4 alloy electrode, the alloy was treated in 6 mol/L KOH+0.02 mol/L KBH4 solution. The results showed that the surface treatment improves the electrochemical performances such as the electrocatalytic activity, high-rate dischargeability and cycling durability of the alloy electrode.
Key words: hydrogen storage alloy; electrode; Ca-substitution; surface modification