Electrochemical performance of Li3V2(PO4)3/C cathode materials using stearic acid as a carbon source

The Li3V2(PO4)3/C cathode materials are synthesized by a simple solid-state reaction process using stearic acid as both reduction agent and carbon source. Scanning electron microscopy and transmission electron microscopy observations show that the Li3V2(PO4)3/C composite synthesized at 700 °C has uniform particle size distribution and fine carbon coating. The Li3V2(PO4)3/C shows a high initial discharge capacity of 130.6 and 124.4 mAh g−1 between 3.0 and 4.3 V, and 185.9 and 140.9 mAh g−1 between 3.0 and 4.8 V at 0.1 and 5 C, respectively. Even at a charge-discharge rate of 15 C, the Li3V2(PO4)3/C still can deliver a discharge capacity of 103.3 and 112.1 mAh g−1 in the potential region of 3.0-4.3 V and 3.0-4.8 V, respectively. Based on the analysis of cyclic voltammograms and electrochemical impedance spectra, the apparent diffusion coefficients of Li ions in the composites are in the region of 1.09 × 10−9 and 4.95 × 10−8 cm2 s−1.