Phase Structure and Electrochemical Hydrogen Storage Characteristics of La0.7Ce0.3Ni3.85Mn0.8Cu0.4Fe0.15-x(Fe0.43B0.57)x (x = 0-0.15) Alloys

Phase structure and electrochemical hydrogen storage performance have been investigated. XRD results indicate that La0.7Ce0.3Ni3.85Mn0.8Cu0.4Fe0.15 alloy is single LaNi5 phase with CaCu5 structure. The alloys containing Fe0.43B0.57 are composed of LaNi5 phase with CaCu5 structure as matrix phase and La3Ni13B2 phase as secondary phases, and the abundance of the secondary phase gradually increases with increasing Fe0.43B0.57 content. As x increases from 0 to 0.15, maximum discharge capacity of the alloy electrodes monotonically decreases from 314.7 to 300.1 mAh/g. High-rate dischargeability at the discharge current density of 1200 mA/g increases from 53.3 % (x = 0) to 64.4% (x = 0.15) with increasing x value. Cycling stability of the alloy electrodes decreases with increasing x value