中國(guó)有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 13 No. 4 August 2003 |
melt-spun AB5 alloy
LEI Yong-quan(雷永泉)1,ZHANG Hong(張 宏)2,
WANG Qi-dong(王啟東)1
（1. Department of Materials Science & Engineering,
Zhejiang University, Hangzhou 310027, China;
2. Energy Science and Technology Department, Shanghai Institute of Microsystems and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China;
3. Ningbo Yunsheng Magnetic Material & Engineering Research Institute, Ningbo Yunsheng Group, Ningbo 315040, China）
Abstract:The crystal structure and electrochemical properties of Ml(NiCoMnAl)5 alloys prepared by both rapid solidification (melt-spinning) and conventional cast methods were systematically investigated. The results show that the charging/discharging cycle life of rapidly solidified alloy is greatly improved, and the mean capacity attenuation rate of the rapidly solidified alloy is 1-3 times lower than that of the as-cast alloy after 600 cycles. All of the melt-spun alloys have almost the same discharge capacity as the as-cast alloy except for the alloy with the cooling rate of 1.8×105K/s, which has the largest discharge capacity of 310mAh/g. The melt-spun alloys need longer activation process than the conventional cast alloy. High rate dischargeability becomes poorer as the cooling rate increases in solidification also. Obviously improved electrochemical properties of the melt-spun alloy are closely related to its fine grain, elimination of secondary phase AlNi3 and uniform composition distribution.
Key words: hydrogen storage alloy; rapid solidification; electrochemical properties
