Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1621084 | Journal of Alloys and Compounds | 2009 | 7 Pages |
Abstract
In order to improve the electrochemical cycle stability of the La-Mg-Ni system A2B7-type electrode alloys, La in the alloy was partially substituted by Zr and the melt-spinning technology was used for preparing La0.75âxZrxMg0.25Ni3.2Co0.2Al0.1 (x = 0, 0.05, 0.1, 0.15, 0.2) electrode alloys. The microstructures and electrochemical performances of the as-cast and quenched alloys were investigated in detail. The results obtained by XRD, SEM and TEM showed that the as-cast and quenched alloys have a multiphase structure which is composed of two main phases (La, Mg)Ni3 and LaNi5 as well as a residual phase LaNi2. The substitution of Zr for La leads to an obvious increase of the LaNi5 phase in the alloys, and it also helps the formation of a like amorphous structure in the as-quenched alloy. The results of the electrochemical measurement indicated that the substitution of Zr for La obviously decreased the discharge capacity of the as-cast and quenched alloys, but it significantly improved their cycle stability. The discharge capacity of the alloys (x â¤Â 0.1) first increased and then decreased with the variety of the quenching rate. The cycle stability of the alloys monotonously rose with increasing quenching rate.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Yang-huan Zhang, Bao-wei Li, Hui-ping Ren, Shi-hai Guo, Qi Yan, Xin-lin Wang,