A new family of hydride electrode materials based on CaNi5-type alloys

作者：Li ZP^*; Suda S

来源：Journal of Alloys and Compounds, 1995, 231(1-2): 751-754.

DOI：10.1016/0925-8388(95)01712-7

• Ca-based alloy
• electrode material
• element substitution
• discharge capacity
• durability

A new family of low-cost hydride electrode materials based on CaNi5 has been studied. CaNi5-series alloys showed the same charge-discharge potential as RNi(5)-type alloys (R, rare-earth metal). A CaNi5 electrode can reach the capacity of 400 mA h g(-1) but only can last a few cycles in an alkaline electrolyte. The extra high capacity of CaNi5 might be brought by Ca corrosion. The CaNi5-type alloys after element substitution demonstrated a discharge capacity of 350-300 mA h g(-1) at a discharge current of 150 mA g(-1). Comparing with B-side substitution in AB(5), A-side substitution is more effective on the durability improvement and keeps the discharge capacity at a high value. It was found that rare-earth and alkaline-earth substitution can dramatically improve the cycling durability. It can be attributed to the lattice stabilization of the alloy and size stabilization of the hydride particles as well as anti-corrosion improvement of the alloy. Zr and Ti addition in Ca0.4La0.6Ni4.7Al0.3 can improve the durability further. The A-rich non-stoichiometric alloy (AB(5)-type Ca-based alloy) showed higher discharge capacity but poorer durability compared with a stoichiometric compound.

• 出版日期1995-12-15