添加剂四氟硼酸四乙基铵对石墨负极界面性能的影响  

Effect of Et_4NBF_4 as additive on interface performance of graphite electrode

作　　者：李艳红[1] 卢海[1] 赵中伟[1] 郝新[1] 张治安[1] 

机构地区：[1]中南大学冶金科学与工程学院,长沙410083

出　　处：《中国有色金属学报》2012年第4期1223-1228,共6页The Chinese Journal of Nonferrous Metals

基　　金："十一五"国家科技支撑计划资助项目(2007BAE12B01);国家自然科学基金资助项目(50974136);中央高校基本科研经费资助项目(2010QZZD0101)

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。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.

关 键 词：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 

分 类 号：TM912.9[电气工程—电力电子与电力传动]