Microstructures and Electrochemical Hydrogen Storage Properties of La0.7Ce0.3Ni3.83Mn0.43Co0.25-xAl0.26Cu0.48(Fe0.43B0.57)x Alloys

Abstract

Microstructures and electrochemical characteristics of La0.7Ce0.3Ni3.83Mn0.43Co0.25-x Al0.26Cu0.48(Fe0.43B0.57)x hydrogen storage alloys have been investigated. XRD results indicate that La0.7Ce0.3Ni3.83Mn0.43Co0.25-xAl0.26Cu0.48 alloy is single LiNi5 phase, and the alloys containing Fe0.43B0.57 are composed of LaNi5 matrix phase and La3Ni13B2 secondary phase, and the abundance of the secondary phase gradually increases with increasing Fe0.43B0.57 content. Maximum discharge capacity of the alloy electrodes monotonically decreases from 311.2 mAh/g (x = 0) to 289.6 mAh/g (x = 0.20). High-rate dischargeability at the discharge current density of 1200 mA/g first increases from 53.1% (x = 0) to 64.0% (x = 0.15), and then decreases to 56.5% (x = 0.20).