Effects of y substitution for la on the microstructure and electrochemical properties of LaNi3.55Mn0.4Al0.3Co 0.75 hydrogen storage alloys

Abstract

The effects of the partial substitution of Y for La in La 1-xYxNi3.55Mn0.4Al 0.3Co0.75 (x = 0, 0.1 and 0.2) alloys were reported in this paper. The single-phase CaCu5-type structure is retained after La is partially substituted by Y. However, the increase of Y content leads to decrease of the lattice parameters and unit-cell volume. Y substitution for La in the alloys is effective to improve the electrochemical properties at room temperature and high temperature. A critical substitution content of Y is found at x = 0.1. © 2008 The Japan Institute of Metals.