Effects of Y Substitution for La on the Microstructure and Electrochemical Properties of LaNi_(3.55)Mn_(0.4)Al_(0.3)Co_(0.75) Hydrogen Storage Alloys

摘要

The effects of the partial substitution of Y for La in La_(1-x)Y_xNi_(3.55)Mn_(0.4)Al_(0.3)Co_(0.75) (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.