(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 采用恒流充放电、循环伏安(CV)和交流阻抗(EIS)测试方法研究四氟硼酸四乙基铵(Et4NBF4)作为锂离子电池电解液添加剂对石墨负极材料界面性质的影响，通过傅里叶变换红外光谱(FTIR)对固体电解质界面膜(SEI)的成分变化进行分析。结果表明：添加剂Et4NBF4参与了SEI膜的形成，提高了人造石墨(AG)/Li半电池充电容量和后续的循环效率，但是降低了首次充放电效率；首次放电过程中1.0~0.5 V是SEI膜形成和生长的电位区间，而0.5 V以下SEI膜进行不断的修复；添加少量Et4NBF4降低了SEI膜阻抗，提高了电解液与石墨负极的相容性。
关键字: 锂离子电池；电解液；添加剂；四氟硼酸四乙基铵；固体电解质相界面膜
graphite electrode
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effect of tetraethylammonium tetrafluoroborate (Et4NBF4) on the graphite interface performance of lithium ion battery in carbonate-based electrolytes was studied by constant current charge-discharge test, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), as well as the Fourier transform infra-red (FTIR) spectroscopy. The results indicate that the charge capacity and following cycle efficiency are improved while the initial charge-discharge efficiency is reduced by adding Et4NBF4 because Et4NBF4 participates in forming SEI film. SEI film forms in the potential range of 1.0−0.5 V during the initial discharge, and repairs below 0.5 V. The impedance of SEI film is reduced by adding Et4NBF4. Et4NBF4 additive can effectively improve the compatibility between electrolyte and graphite anode.
Key words: lithium ion battery; electrolyte; additive; tetraethylammonium tetrafluoroborate; solid electrolyte interface film
