Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (4): 700-706.doi: 10.3866/PKU.WHXB201501261

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Synthesis of Fluorinated Polyanionic Lithium Ion Insertion/Extraction Material LiVPO4F/C by Carbon Thermal Reduction Assisted Sol-Gel Method

HUANG Zhi-Peng1, GUO Lin-Yu1, GUO Chao2, ZHAO Meng-Meng1, WANG Xue-Hua1, JIN Zhao1, LUO Jin-Hua1, WANG Xin1, FENG Ji-Jun1   

  1. 1 School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China;
    2 School of Chemistry and Biological Engineering, Qilu Institute of Technology, Zhangqiu 250200, Shandong Province, P. R. China
  • Received:2014-11-19 Revised:2015-01-23 Published:2015-04-03
  • Contact: FENG Ji-Jun E-mail:chm_fengjj@ujn.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51102114), Sci-Tech Development Project of Jinan, China (201401234), and National Undergraduate Training Programs for Innovation and Entrepreneurship, China (201310427010).

Abstract:

LiVPO4F/C, as a cathode material of lithium- ion batteries, was prepared by carbon thermal reduction assisted sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge-discharge cycles, cyclic voltammogram (CV), and electrochemical impedance spectroscopy (EIS) were employed to investigate the effects of sintering time and temperature on the structure and corresponding electrochemical performance of as prepared materials. At a sintering time of 4 h, pure phase LiVPO4F/C material was obtained when the temperature is settled at 450 ℃. The as-produced LiVPO4F/C exhibited discharge capacities of 193.2, 175.6, and 173.7 mAh·g-1 at 0.1C, 0.5C, and 1.0C rates, respectively. Li3V2(PO4)3 impurities are formed and increased with increasing calcination temperature. When sintered at 650 ℃ Li3V2(PO4)3 is turn out to be the main phase. On the other hand, optimal duration time at high temperature could also inhibit the decomposition of LiVPO4F and decrease the formation of Li3V2(PO4)3 impurities, improving electrochemical performance. Optimal conditions were found at a residence time of 3 h when the precursor is sintered at 550 ℃.

Key words: Lithium-ion battery, Cathode material, Sol-gel, Carbon thermal reduction, LiVPO4F/C

MSC2000: 

  • O646