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(O-4)3/C composite synthesized at 700 degrees 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 Vat 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 x 10(-9) and 4.95 x 10(-8) cm(2) s(-1). (C) 2010 Elsevier Ltd. All rights reserved.