物理化学学报 >> 2015, Vol. 31 >> Issue (4): 700-706.doi: 10.3866/PKU.WHXB201501261

电化学和新能源 上一篇    下一篇

碳热还原辅助溶胶-凝胶法制备氟代聚阴离子型嵌/脱锂材料LiVPO4F/C

黄志鹏1, 郭琳昱1, 郭超2, 赵盟盟1, 王雪华1, 金钊1, 罗晋花1, 王鑫1, 冯季军1   

  1. 1 济南大学化学化工学院, 济南250022;
    2 齐鲁理工学院化学与生物工程学院, 山东章丘250200
  • 收稿日期:2014-11-19 修回日期:2015-01-23 发布日期:2015-04-03
  • 通讯作者: 冯季军 E-mail:chm_fengjj@ujn.edu.cn
  • 基金资助:

    国家自然科学基金(51102114), 济南市科技发展计划(201401234)和国家级大学生创新创业训练计划(201310427010)资助项目

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).

摘要:

采用碳热还原辅助溶胶-凝胶法合成了锂二次电池正极材料LiVPO4F/C, 探讨煅烧温度和煅烧时间对所制备材料纯度、结构和电化学性能的影响. 采用X射线衍射(XRD), 扫描电子显微镜(SEM), 恒流充放电, 电化学阻抗谱(EIS)和循环伏安(CV)等手段对不同煅烧温度和时间所得的材料进行结构表征和电化学性能测试. 当煅烧时间为4 h 时, 温度为450 ℃时, 能够得到纯相LiVPO4F/C, 在0.1C、0.5C和1.0C倍率下, 电池放电比容量分别为193.2、175.6 和173.7 mAh·g-1. 随着煅烧温度升高, Li3V2(PO4)3杂相逐渐增多, 650 ℃煅烧后的材料Li3V2(PO4)3 成为主相. 优化煅烧时间也能够有效控制Li3V2(PO4)3 杂相的生成, 能得到电化学性能良好的LiVPO4F/C. 当煅烧温度为550 ℃时, 反应3 h后得到的产物综合电化学性能最优.

关键词: 锂离子电池, 正极材料, 溶胶-凝胶, 碳热还原, LiVPO4F/C

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