Mg intercalation properties into V2O5 gel/carbon composites under high-rate condition

V2O5/carbon composites were prepared from a homogeneous suspension in which vanadium pentoxide sol and acetylene black powder were mixed with acetone acting as a surfactant. The composite was loaded on indium-tin oxide (ITO)-coated glass, and then the magnesium intercalation property and the high-rate charge-discharge performance were evaluated in an electrolyte of Mg(ClO4)(2)/acetonitrile at room temperature. In cyclic voltammetry, two main peaks of a reversible redox reaction were observed. It was determined that 1.84 mol of Mg per mol of V2O5 were inserted in the first cycle at a relatively slow sweep rate of 0.1 mV s(-1), which corresponds to a specific capacity of 540 mAh (g-V2O5)(-1). Galvanostatic charge-discharge tests at various current densities showed a high capacity of about 600 mAh (g-V2O5)(-1) at a current density of 1.0 A (g-V2O5)(-1), and about 300 mAh (g-V2O5)(-1) was maintained even at 20 A (g-V2O5)(-1). (C) 2003 The Electrochemical Society.