Sol-gel synthesis of Li3V2(PO4)3/C cathode materials with high electrical conductivity

The Li3V2(PO4)(3)/C composite (LVP) including nanorods and irregular solids were successfully prepared by a sol-gel method. The influences of different precursors on the LVP cathode materials were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size distribution measurement and electrochemical methods. The LVP/C electrodes present good rate capability and excellent cyclic performance when they cycle in the range of 3.0-4.3 V. The LVP1/C composite prepared by NF4H2PO4, LiOH, NH4VO4 and citric acid delivers the initial discharge capacity of 109.6 mAh g(-1) at 20 C discharge rate and it still maintains 56.9 mAhg(-1) after 450 cycles, with the discharge capacity retention of 51.9%. For the LVP2/C composite synthesized by LiH2PO4, NH4VO4 and citric acid, however, the discharge capacities in the 1st and 450th cycles at 20 C discharge rate are 107.1 and 96.2 mAhg(-1), respectively, with only 10.2% loss. The excellent rate capacity is attributed to the pure phases, nanorod structure, small particles and uniform carbon coating. (C) 2013 Elsevier Ltd. All rights reserved.