Enhanced electrochemical properties of Ti1.4V0.6Ni with Mo2C or WC coating as negative electrodes for Ni-MH battery

Abstract Composites of Ti 1.4 V 0.6 Ni coated with Mo 2 C or WC are prepared through ball milling, and their electrochemical properties are investigated as negative electrode materials in a Ni-MH battery system. Mo 2 C and WC disperse adequately on the surface of the Ti 1.4 V 0.6 Ni alloy to form Ti 1.4 V 0.6 Ni@Mo 2 C and Ti 1.4 V 0.6 Ni@WC, respectively. The composites exhibit higher electrochemical hydrogen storage capacity and more stable cycling stability than the bare alloy. Particularly, the capacity conservation rate of Ti 1.4 V 0.6 Ni@WC is 67.4% after 200 cycles, and it increases by 29.5% compared with Ti 1.4 V 0.6 Ni alloy. A study of the kinetics demonstrates that Mo 2 C or WC coating accelerates the charge-transfer reaction and increases the electrochemical activity of the Ti 1.4 V 0.6 Ni electrode. The improvements to electrochemical properties of Ti 1.4 V 0.6 Ni may be due to the proper Mo 2 C or WC coating with copacetic electrocatalytic activity and anti-pulverization ability.