Grinding-sol-gel synthesis and electrochemical performance of mesoporous Li3V2(PO4)3 cathode materials

Li3V2(PO4)3 precursor was obtained with V2O5·nH2O, LiOH·H2O, NH4H2PO4 and sucrose as starting materials by grinding-sol-gel method, and then the monoclinic-typed Li3V2(PO4)3 cathode material was prepared by sintering the amorphous Li3V2(PO4)3. The as-sintered samples were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption and electrochemical measurement. It is found that Li3V2(PO4)3 sintered at 700 °C possesses good wormhole-like mesoporous structure with the largest specific surface area of 188 cm2/g, and the smallest pore size of 9.3 nm. Electrochemical test reveals that the initial discharge capacity of the 700 °C sintered sample is 155.9 mA·h/g at the rate of 0.2C, and the capacity retains 154 mA·h/g after 50 cycles, exhibiting a stable discharge capacity at room temperature.