Hydrogen storage composite alloy Ti0.10Zr0.15V0.35Cr0.10Ni0.30–10% LaNi3 was prepared by two-step arc-melting to improve the electro-catalytic activity and the kinetic performance of Ti-V-based solid solution alloy. The electrochemical properties and synergetic effect of the composite alloy electrode were systematically investigated by using X-ray diffractometry, field emission scanning electron microscopy, energy-dispersive spectrometry, electrochemical impedance spectroscopy and galvanostatic charge/discharge test. It is found 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 the secondary phase is formed in the composite alloy. The comprehensive electrochemical properties of the composite alloy electrode are significantly improved. The activation cycle number, the maximum discharge capacity and the low temperature dischargeability of the composite alloy are 5 cycles, 362.5 mA-h/g and 65.84% at 233 K, respectively. It is suggested that distinct synergetic effect occurs in the activation process, composite process, cyclic process and discharge process at a low or high temperature under different current densities, in the charge–transfer resistance and exchange current density.
CeCo5 alloy was prepared from the mixture of cobalt oxide （Co3O4） and cerium oxide （CeO2） powders by electro-deoxidation in molten calcium chloride. The effects of the cell voltage and sintering temperature on the electrolysis process were reported. The electro-deoxidation mechanism was investigated by potentiodynamic polarization using a molybdenum cavity electrode in conjunction with characterization of the products from constant voltage electrolysis under different conditions by XRD and SEM. The electrochemical property of CeCo5 alloy was investigated by cyclic voltammetry measurements. The results show that the electro-deoxidation rate increases with increasing the cell voltage and decreasing the sintering temperature. The pure CeCo5 can be prepared by direct electro-deoxidation of mixed CeO2/Co3O4 pellets sintered at 850 °C when the cell voltage of 3.1 V is applied. The electro-deoxidation proceeds by the simultaneous reduction of Co3O4 to Co and reduction of CeO2 to CeOCl, followed by CeOCl reduction on the pre-formed Co to form CeCo5 alloy which shows a good cycling stability.
