Preparation and characterization of Mg 0.9Ti 0.06V 0.04Ni–carbon material composites for electrochemical use

Abstract

Effects of both bulk and surface modifications of amorphous MgNi alloy on its physicochemical and electrochemical characteristics were investigated. It was found from results of thermogravimetry (TG) that the partial substitution of Mg in MgNi with both Ti and V and the subsequent surface modification with graphite greatly enhanced the hydrogen desorbability of the MgNi alloy compared with either the partial substitution or the surface modification. In charge–discharge cycle tests, Mg 0.9Ti 0.06V 0.04Ni–graphite composite exhibited better high-rate dischargeability and cycle performance than either Mg 0.9Ti 0.06V 0.04Ni alloy or MgNi–graphite composite. These results indicate that both bulk and surface modifications of the MgNi alloy are very effective in improving their hydrogen desorbability and charge–discharge characteristics.