Microstructures and electrochemical properties of La0.7Ce0.3Ni3.7Co0.7-xAl0.2Mn0.4(Fe0.43B0.57)x (x=0-0.4) hydrogen storage alloys

X-ray diffraction results indicate that pristine alloy has a single LaNi5 phase and the alloys containing Fe0.43B0.57 consist of the matrix LaNi5 phase and the La3Ni13B2 secondary phase. The abundance of La3Ni13B2 phase increases with increasing x value. Maximum discharge capacity of the alloy electrodes monotonically decreases from 336.1 mAh/g (x = 0) to 281.2 mAh/g (x = 0.4). High-rate dischargeability of the alloy electrodes first increases with increasing x from 0 to 0.20, and then decreases when x increases to 0.4. Cycling stability decreases with increasing x from 0 to 0.4.