Electrochemical Characteristics and Synergetic Effect of Ti0.10Zr0.15V0.35Cr0.10Ni0.30+5wt% LaNi5 Composite Hydrogen Storage Alloy

Ti0.10Zr0.15V0.35Cr0.10Ni0.30+5wt% LaNi5 composite hydrogen storage alloy was prepared by two-step arc melting in order to improve performance of Ti-V-based solid solution alloy. X-ray diffractometry (XRD) and field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM-EDS) show that the main phase of the composite alloy is composed of V-based solid solution phase with a BCC structure and C14 Laves phase with hexagonal structure, while secondary phase also exists in the composite alloy. Electrochemical test shows that P-C-T properties, activation performance, maximum discharge capacity, cyclic stability, low temperature dischargeability and kinetics properties of the composite alloy are significantly improved. The activation cycle number and the maximum discharge capacity of the composite alloy are 5 cycles and 353.9 mAh.g(-1), respectively,and the low temperature discharge ability is 50.26% at 233 K. Synergetic effect appears in the maximum hydrogen absorption capacity, plateau pressure, the charge-transfer resistance and the exchange current density. The synergetic effect of the discharge capacity appears in cycles, high/low temperature and high rate discharge process.