Electrochemical performance of ZrMn 0.5V 0.4Ni 1.1Co x Laves phase alloy electrode

Abstract

The electrochemical performance of ZrMn 0.5V 0.4Ni 1.1Co x ( x=0.05, 0.1, 0.15, 0.2) system alloys, based on ZrMn 0.5V 0.4Ni 1.1, are investigated intensively. With the increase in Co content, the maximum capacity, high-rate dischargeability (HRD) and CL of the alloy electrode decreases, and the self-dischargeability increases. Electrochemical activities of ZrMn 0.5V 0.4Ni 1.1Co x alloy electrodes are worse than that of the matrix alloy. While, the alloy electrodes are heat-treated by hot alkaline solutions, their activities improve greatly, and there are not more than four cycles to reach the maximum capacity. However, the maximum capacities show a small decrease. The reversible capacity loss mainly results from desorption of hydrogen from hydride, and is affected by the stability of hydrides. E of ZrMn 0.5V 0.4Ni 1.1Co x alloy electrodes agrees well with their reversible capacity loss. In all the investigated alloy electrodes, ZrMn 0.5V 0.4Ni 1.1Co 0.05 alloy electrode has the most excellent properties in capacity, CL, HRD and self-dischargeability. ZrMn 0.5V 0.4Ni 1.1Co 0.05 alloy is a favorable alloy for use as an active electrode if its temperature property will be improved.