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

• DOI: 10.1016/j.electacta.2010.11.073
• Publication Date: 2010-11-30T10:38:16Z
• Authors: Y.Q. Qiao; X.L. Wang; J.Y. Xiang; D. Zhang; W.L. Liu; J.P. Tu
• Keywords: Stearic acid; Carbon fibers

Abstract 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.