High-Temperature Characteristics of Melt-Spun Hydrogen Storage Alloys
In this work, the electrochemical discharge capacity of melt-spun (MmY)1 (NiCoMnAl)5 ribbons, in which the content of yttrium was 0-2.5wt%, was studied in the temperature range of 30~80oC. It was found that adding element yttrium made the electrochemical capacity of the compounds increased. The capacity obtained was 333mAh/g at 30 oC and 247 mAh/g at 80oC when the content of yttrium was 2.0wt%. In addition, 70~85% recovery of the capacity was obtained due to better antioxidation. The increase of charging/discharging efficiency with yttrium substitution for Mm in melt-spun ribbons illustrated by the potential characteristics of charging/discharging is ascribed to the flatter and lower hydride formation potential, as well as the higher hydrogen evolution potential. Moreover, This effect is more prominent with increasing yttrium content.
Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie
R. Li et al., "High-Temperature Characteristics of Melt-Spun Hydrogen Storage Alloys", Materials Science Forum, Vols. 475-479, pp. 2505-2508, 2005