Composites of V2O5 aerogel and nickel fiber as high rate intercalation electrodes

Amorphous vanadium pentoxide (V2O5) has been investigated as an intercalation material for Li-ion batteries due to its high specific energy and high capacity for Li intercalation. However, the rate of insertion is typically limited by lithium diffusion in the host and bl; its modest conductivity. The present work demonstrates that high intercalation rates are possible if the host microstructure is modified to decrease the characteristic lithium diffusion distance and the characteristic conduction distance. Thin films of V2O5 were grown by preferential gelation on sintered nickel fibers via a sol-gel route. Electrochemical impedance measurements of the composite electrodes indicated that diffusion limitations in the host were successfully avoided. Constant current cycling and cyclic voltammetry were also used to characterize the composites. Specific powers. based on mass of active material, of almost 6 MW/kg were observed. (C) 1999 The Electrochemical Society. S0013-4651(98)03-072-9. All rights reserved.