物理化学学报 >> 2008, Vol. 24 >> Issue (07): 1302-1306.doi: 10.3866/PKU.WHXB20080731

研究简报 上一篇    下一篇

石墨负极在Et4NBF4+LiPF6/EC+PC+DMC电解液中的电化学行为

李凡群; 赖延清; 张治安; 高宏权; 杨娟   

  1. 中南大学冶金科学与工程学院, 长沙 410083
  • 收稿日期:2007-12-28 修回日期:2008-03-21 发布日期:2008-07-04
  • 通讯作者: 赖延清 E-mail:13975808172@126.com

Electrochemical Behaviors of Et4NBF4+LiPF6/EC+PC+DMC Electrolyte on Graphite Electrode

LI Fan-Qun; LAI Yan-Qing; ZHANG Zhi-An; GAO Hong-Quan; YANG Juan   

  1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, P. R. China
  • Received:2007-12-28 Revised:2008-03-21 Published:2008-07-04
  • Contact: LAI Yan-Qing E-mail:13975808172@126.com

摘要: 在PC+EC+DMC复合溶剂体系中, 研究了Et4NBF4(四氟硼酸四乙基铵)与LiPF6组成的复合盐电解质对石墨负极材料界面性质的影响. 用循环伏安和恒电流充放电测试方法研究了电解液与石墨负极的相容性, 通过傅里叶变换红外光谱(FTIR)对固体电解质中间相膜(SEI)的成分变化进行了研究. 结果表明, 电解液中的Et4NBF4参与了SEI膜的形成; 当Et4NBF4浓度为0.2 和0.5 mol·L-1时, 电池首次充放电不可逆容量损失明显减少, 循环效率分别上升到76.0%和81.6%. Et4NBF4/LiPF6复合盐电解质改善了PC基电解质与石墨负极的相容性.

关键词: 锂离子电池, 电解液, 复合盐四氟硼酸四乙基铵, 固体电解质相界面膜

Abstract: Et4NBF4/LiPF6-based electrolytes were investigated to study the effects of the electrolytes with blend solvent EC+PC+DMC on the interface characteristics of graphite electrode. Cyclic voltammetry (CV) and charge-discharge test were used to examine the compatibility between the electrolytes and graphite anode. FTIR spectroscopy was used to analyze the variational component of the solid electrolyte interface (SEI) film. The results showed that Et4NBF4 was concerned with the formation of SEI film. Irreversible capacity in the first circle remarkably reduced when the concentrations of Et4NBF4 were 0.2 and 0.5 mol·L-1, and the circle efficiencies rose to 76.0% and 81.6%, respectively. LiPF6/Et4NBF4 blend-salt electrolytes system can effectively improve the compatibility between PC-based electrolyte and graphite anode.

Key words: Li-ion battery, Eectrolyte, Blend salt, Et4NBF4, SEI film

MSC2000: 

  • O646