Characteristics of LaNi 5-based hydrogen storage alloys modified by partial substituting La for Ce

Abstract

Characteristics including microstructure, thermodynamics, electrochemical and kinetic properties of AB 5-type hydrogen storage alloys La 0.8(1− x) Ce 0.8 x (PrNd) 0.2B 5, where B 5 is Ni 3.55Co 0.75Mn 0.4Al 0.3, were studied systematically. It indicated that these alloys have a typical single-phase structure of the CaCu 5-type, the cell parameters of a and c changing slightly with the Ce content x. The equilibrium pressure of the alloys for hydrogen sorption increases with the increase of the Ce content, the hysteresis becomes smaller, and the thermodynamic stability of corresponding hydride becomes lower. The effect of the Ce content on the electrochemical activation of the alloys is negligible, while its effects on the discharge capacity, high-rate discharge ability, charge–discharge voltage and kinetic performance of the alloys are significant.