Electrochemical performance of nanocrystalline Li3V2(PO4)3/carbon composite material synthesized by a novel sol-gel method

A novel sol-gel method based on V2O5 center dot nH(2)O hydro-gel was developed to synthesize nanocrystalline Li3V2(PO4)(3)/carbon composite material. In this route, V2O5 center dot nH(2)O hydro-gel, NH4H2PO4, Li2CO3 and high-surface-area carbon were used as starting materials to prepare precursor, and the Li3V2 (PO4)(3)/carbon was obtained by sintering precursor at 750 degrees C for 4 h in flowing argon. The sol-gel synthesis ensures homogeneity of the precursors and improved reactivity. The sample was characterized by XRD, SEM and TEM. X-ray diffraction results show Li3V2(PO4)(3) sample is monoclinic structure with the space group of P2(1)/n. The TEM image indicates that the Li3V2(PO4)(3) particles modified by conductive carbon are about 70 nm in diameter. The Li3V2(PO4)(3)/carbon system showed that the discharge capacities in the first and 50th cycle are about 155.3 and 143.6 mAh/g, respectively, in the range of 3.0-4.8 V. The sol-gel method is fit for the preparation of Li3V2(PO4)(3)/carbon composite material which may offer some favorable properties for commercial application. (c) 2006 Published by Elsevier Ltd.