The Application of Graphite in the Preparation of Cathode Material Li3V2(PO4)3/C

摘要

Graphite and citric acid are simultaneously employed as carbon sources to prepare Li3V2(PO4)3/C (LVP/C) cathode material by a sol-gel method. The effects of graphite on the structure and electrochemical performance of LVP/C are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Bruna-uer-Emmett-Teller (BET) method, and electrochemical measurements. The XRD patterns indicate that graphite influences the rate and the direction of the LVP crystal growth. The SEM results show that the sample has a unique porous wafer-like morphology. The sample has initial discharge capacities of 128.7 and 124 mAh g~(-1) at 0.2 and 5 C rates in the potential range of 3.0-4.3 V, respectively. The capacity retentions are 99.8% and 93.3% after 100 circles. In addition, a simple method for the determination of carbon content of LVP/C sample is put forward.