Page 147 - 《精细化工》2022年第4期

第 39 卷第 4 期 精 细 化 工 Vol.39, No.4
2022 年 4 月 FINE CHEMICALS Apr. 2022

有机电化学与工业
氟代苯腈类添加剂对锂离子电池性能的影响

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张嘉玉，雷 英，李颜利
（四川轻化工大学 化学工程学院，四川 自贡 643002）

摘要：以 2-三氟甲基苯腈（2-TB）、3-三氟甲基苯腈（3-TB）、4-三氟甲基苯腈（4-TB）作为锂离子电池电解液
添加剂，考察其取代基位置对电池性能的影响。首先，通过量子化学方法计算了 3 种添加剂的最高占据分子轨
道（HOMO）和最低未占据分子轨道（LUMO）；接着，测试了电池的电化学性能；最后，采用 SEM、TEM 及
FTIR 表征了钴酸锂电极的表面形貌及组成。结果表明，相对于不含添加剂的基础电解液，含有质量分数为 0.5%
添加剂的电解液可形成一层致密而稳定的正极电解液界面保护膜，从而提高电解液的电化学性能。其中，与 2-TB
和 3-TB 相比，4-TB 可在首次充放电后形成 15.0~40.0 nm 的电极保护膜，将界面传输电阻降低至 61.63 Ω，循环
30 圈后的放电比容量提高至 126.8 mA·h/g。不同取代基在苯环对位的电化学性能最佳，其次是邻位和间位。
关键词：锂离子电池；量子化学；电化学；稳定性；含氟添加剂；有机电化学
中图分类号：TM912 文献标识码：A 文章编号：1003-5214 (2022) 04-0783-07

Effects of fluorinated benzonitrile additives on performance of
lithium ion batteries

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ZHANG Jiayu, LEI Ying, LI Yanli
（School of Chemical Engineering , Sichuan University of Science & Engineering, Zigong 643002, Sichuan, China）

Abstract: 2-Trifluoromethylbenzonitrile (2-TB), 3-trifluoromethylbenzonitrile (3-TB) and
4-trifluoromethylbenzonitrile (4-TB) were used as lithium-ion battery electrolyte additives to investigate the
influence of substituent position on battery performance. The highest occupied molecular orbital (HOMO)
and lowest unoccupied molecular orbital (LUMO) of the three additives were firstly calculated by quantum
chemistry method, followed by electrochemical performance of lithium ion battery analysis. Finally, the
surface morphology and composition of lithium cobaltate electrode were characterized by SEM, TEM and
FTIR. The results showed that, compared with the control without any additives, the electrolytes containing
additives with a mass fraction of 0.5% could form a dense and stable layer of interface protection film for
the anode, thus led to electrochemical performance improvement, 4-TB of the three additives could form a
15.0~40.0 nm electrode protective film upon the first charge and discharge cycle, reduced the interface
transmission resistance to 61.63 Ω, and increased the discharge specific capacity to 126.8 mA·h/g after 30
cycles. The results suggested that substituents on the para-position of phenyl ring had most influence on
electrochemical performance, followed by ortho- and meta-position.
Key words: lithium-ion battery; quantum chemistry; electrochemistry; stability; fluoride additives; electro-
organic chemistry

锂离子电池具有工作电压高、循环寿命长、能 天、航海、通讯及电子产品等许多领域得到广泛应
量密度大和对环境友好等众多优点，已在航空、航 用 [1-2] 。电解液是锂离子电池的重要组成部分，由锂

收稿日期：2022-01-26; 定用日期：2022-03-16; DOI: 10.13550/j.jxhg.20220099
基金项目：化学合成与污染控制四川省重点实验室开放项目资助（CSPC202102）；四川省科技厅重点研发项目资助（2020YFG0422）；
自贡市重点科技计划项目资助（2019YYJC19）；四川轻化工大学人才引进项目资助（2018RCL02）
作者简介：张嘉玉（1995—），女，硕士生，E-mail：1195122828@qq.com。联系人：李颜利（1987—），女，博士，E-mail：liyanli0523@
suse.edu.cn。