物理化学学报 >> 2009, Vol. 25 >> Issue (10): 1967-1971.doi: 10.3866/PKU.WHXB20090932

研究论文 上一篇    下一篇

LiBOB基电解液成膜性及其循环性能

谭晓兰, 程新群, 马玉林, 左朋建, 尹鸽平   

  1. 哈尔滨工业大学化工学院, 哈尔滨 150001
  • 收稿日期:2009-04-09 修回日期:2009-06-09 发布日期:2009-09-29
  • 通讯作者: 尹鸽平 E-mail:yingphit@hit.edu.cn

Film Formation and Cycleability of LiBOB-Based Electrolyte

TAN Xiao-Lan, CHENG Xin-Qun, MA Yu-Lin, ZUO Peng-Jian, YIN Ge-Ping   

  1. College of Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
  • Received:2009-04-09 Revised:2009-06-09 Published:2009-09-29
  • Contact: YIN Ge-Ping E-mail:yingphit@hit.edu.cn

摘要:

通过循环伏安(CV)、电化学阻抗谱(EIS)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和傅立叶变换红外(FTIR)光谱研究了双乙二酸硼酸锂(LiBOB)基电解液在石墨表面的成膜性及其在常温(25 ℃)和高温(70 ℃)下对石墨循环性能的影响. 结果表明, LiBOB基电解液的成膜电位在1.7 V, 其中BOB-离子还原形成的草酸盐是固体电解质相界面(SEI)膜的有效成分之一. 电化学阻抗谱显示, 膜阻抗在循环过程中呈现减小趋势, 这有利于提高循环稳定性. 在常温和高温条件下, 石墨在该电解液体系中均表现出优于其在LiPF6基电解液体系中的循环性能.

关键词: 锂离子电池, 电解液, LiBOB, SEI膜

Abstract:

The formation of solid electrolyte interphase (SEI) filmon graphite in a lithiumbis(oxalato)borate (LiBOB)-based electrolyte was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). The effects of SEI filmon the cycleabilities of graphite were examined at roomtemperature (25 ℃) and at high temperature (70 ℃). Results showed that the SEI filmwas formed at around 1.7 V and BOB- ions were reduced to oxalate, which was one of the components of the SEI film. EIS showed that the impedance of the SEI film decreased during the charge/discharge cycle and this was favorable for cycle stability. Whether it was at room temperature or at high temperature, the graphite had better cycleability in the LiBOB-based electrolyte than in the LiPF6-based electrolyte.

Key words: Li-ion battery, Electrolyte, LiBOB, SEI film

MSC2000: 

  • O646