Keywords: High-rate dischargeability / Low-temperature dischargeability / Exchange current density / Hydrogen diffusion coefficient / Alloys / X-ray diffractionThe structure, hydrogen storage property, and electrochemical characteristics of the La 0.7 Mg 0.3 Ni 4.5-x (Al 0.5 Mo 0.5 ) x (x = 0, 0.2, 0.4, 0.6, 0.8) hydrogen storage alloys have been investigated systematically. The X-ray powder diffraction and Rietveld analysis results reveal that all the alloys mainly consist of the La(La, Mg) 2 Ni 9 phase and the LaNi 5 phase. The electrochemical measurements show that the maximum discharge capacity increases first from 246.3 (x = 0) to 345.4 mAh/g (x = 0.6) and then decreases to 317.6 mAh/g (x = 0.8), which is consistent with the variation of the hydrogen storage capacity indicated by the P-C isotherms. For the dis-