高等学校化学学报

高等学校化学学报 ›› 2002, Vol. 23 ›› Issue (7): 1375.

• 研究论文 • 上一篇    下一篇

锂在高有序热解石墨(HOPG)电极中的扩散系数

努丽燕娜, 万传云, 严曼明, 庄继华, 江志裕   

  1. 复旦大学化学系, 上海 200433
  • 收稿日期:2000-08-28 出版日期:2002-07-24 发布日期:2002-07-24
  • 通讯作者: 江志裕(1940年出生),男,教授,博士生导师,从事表面电化学和高能化学电源研究.E-mail:zyjiang@fudan.ac.cn E-mail:zyjiang@fudan.ac.cn
  • 基金资助:

    国家自然科学基金(批准号:28933090)

Diffusion Coefficient of Lithium for Intercalation in Highly Oriented Pyrolytic Graphite

NU LI Yun-Na, WAN Chuan-Yun, YAN Man-Ming, ZHUANG Ji-Hua, JIANG Zhi-Yu    

  1. Department of Chemistry, Fudan University, Shanghai 200433, China
  • Received:2000-08-28 Online:2002-07-24 Published:2002-07-24

PDF (PC)

被引次数

17

摘要： 用循环伏安、交流阻抗和电位阶跃法研究了平板高有序热解石墨(HOPG)电极在1mol/LLiPF6和体积比为1∶1的EC/DMC溶液中的电化学行为.结果表明,石墨的嵌锂反应仅发生在边界面上.随着嵌锂量的增加,表面SEI膜的电阻和嵌入反应的极化电阻减小.用交流阻抗谱和电位阶跃方法测定的锂在高有序热解石墨中的扩散系数一致,并随充电程度的增加而显著减小.在电极电位(vs.Li/Li+) 0.2～0.05V区间,扩散系数由10-11cm2/s下降到10-12cm2/s.

关键词: 高有序热解石墨(HOPG), 锂离子电池负极, 扩散系数, 嵌入反应

Abstract: The diffusion coefficient of lithium in Highly Oriented Pyrolytic Graphite(HOPG) was measured by using electrochemical impedance spectra(EIS) and potential step methods in 1mol/L LiPF6, V(EC)∶V(DMC)=1∶1 solution. It was found that the resistance of SEIfilm and the polarization resistance decreased with the increase of lithium intercalation degree. Aagreement was obtained between the diffusion coefficient values measured from these two methods. The diffusion coefficient of lithium in HOPGdecreased from 10-11 cm2/s to 10-12 cm2/s in the potential region of 0.2-0.05 V.

Key words: Highly oriented pyrolytic graphite, Negative electrode of lithium ion battery, Diffusion coefficient, Intercalation reaction

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