Distinct synergistic effect in Ti0.10Zr0.15V0.35Cr0.10Ni0.30 + 1.0 wt.% LaNi5 hydrogen storage composite electrode

Distinct synergistic effect of Ti0.10Zr0.15V0.35Cr0.10Ni0.30 + 1.0 wt.% LaNi5 hydrogen storage composite prepared by two-step arc-melting has been analyzed and discussed systematically. X-ray diffractometry (XRD) and scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS) show that the main phase of 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 properties of the composite alloy electrode have significantly been improved. It is suggested that distinct synergistic effect appears in the activation process, in the composite process, in the cyclic process, in the discharge process at low/high temperature and at different current density, and in the charge-transfer resistance and the exchange current density for the hydrogen storage composite electrode, which is probably ascribed to the formation of the secondary phase in the composite alloy.

► Synergistic effect appears in the activation process. ► Synergistic effect appears in the composite process. ► Synergistic effect exists in the cyclic process. ► Synergistic effect appears in the discharge capacity at low/high temperature. ► Synergistic effect exists in HRD, in Rct and in I0.