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过程工程学报 ›› 2018, Vol. 18 ›› Issue (3): 605-611.DOI: 10.12034/j.issn.1009-606X.217371

• 过程与工艺 • 上一篇    下一篇

含LiDFOB的FEC/PC/DMC基电解液的高电压电化学性能

张 亮1,2, 张 兰2, 陈仕谋2, 王轶博3, 吕兴梅2*   

  1. 1. 中国科学院大学化学与化工学院,北京 100049; 2. 中国科学院过程工程研究所多相复杂系统国家重点实验室,绿色过程与工程重点实验室,离子液体清洁过程北京市重点实验室,北京 100190; 3. 北京工商大学理学院,北京 100048
  • 收稿日期:2017-10-24 修回日期:2017-11-14 出版日期:2018-06-22 发布日期:2018-06-06
  • 通讯作者: 吕兴梅 xmlu@ipe.ac.cn
  • 基金资助:
    基于离子液体体系的甲壳素溶解分离过程基础研究;离子液体在生物质分离转化利用中的应用基础研究;基于离子液体的生物质转化关键科学问题

High Voltage Electrochemical Properties of FEC/PC/DMC Electrolyte with LiDFOB

Liang ZHANG1, 2, Lan ZHANG2, Shimou CHEN2, Yibo WANG3, Xingmei LV2*   

  1. 1. School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China; 2. Beijing Key Laboratory of Ionic Liquids Clean Process, Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; 3. School of Science, Beijing Technology and Business University, Beijing 100048, China
  • Received:2017-10-24 Revised:2017-11-14 Online:2018-06-22 Published:2018-06-06
  • Contact: LU Xing-mei xmlu@ipe.ac.cn

摘要: 利用氟代碳酸乙烯酯(FEC)和二氟草酸硼酸锂(LiDFOB)优良的成膜性、稳定性和耐高压性,研究了在1 mol/L LiPF6 FEC/碳酸丙烯酯(PC)/碳酸二甲酯(DMC)中加入LiDFOB和三(三甲基硅烷)硼酸酯(TMSB)对高电压材料LiNi0.5Mn1.5O4电化学性能的影响,利用循环伏安法和扫描电镜分析了两种电解液中电化学性能的差异. 结果表明,在FEC基电解液中加入LiDFOB和添加剂TMSB使电解液的分解电位提高至5.5 V(vs. Li/Li+)以上,对铝箔有良好的钝化作用. Li/LiNi0.5Mn1.5O4半电池在含LiDFOB和TMSB的电解液中的初始放电比容量达126.8 mA?h/g,库伦效率为99%,充放电200次后比容量仍为108.2 mA?h/g,容量保持率为85.3%. 而在不含LiDFOB和TMSB的电解液中,电池容量迅速衰减,85次充放电循环后容量保持率仅为60.7%.

关键词: 高电压电解液, LiDFOB, FEC, 锂离子电池, LiNi0.5Mn1.5O4

Abstract: Fluoroethylene carbonate (FEC) and lithium oxalyldifluoroborate (LiDFOB) were regarded as the excellent solvent and additive for high voltage lithium-ion battery electrolyte due to their excellent electrochemical stability and protection film forming ability. LiDFOB and Tris(trimethylsilyl)borate (TMSB) were chosen as additive of 1 mol/L LiPF6 FEC/Propylene carbonate (PC)/Dimethyl carbonate (DMC) electrolyte for LiNi0.5Mn1.5O4 battery. The electrochemical performances of the electrolytes LiDFOB and additive TMSB have been systematically investigated. The differences between these two electrolytes were also demonstrated by SEM and cyclic voltammetry. The results showed that decomposed potential of the electrolyte with LiDFOB+additive TMSB can be enhanced to 5.5 V (vs. Li/Li+) and the Al current collector could be effectively passivated. The initial discharge capacity of Li/LiNi0.5Mn1.5O4 half cell operated with electrolyte with LiDFOB and TMSB was 126.8 mA?h/g, the coulomb efficiency was 99%. After 200 cycles, the discharge specific capacity was 108.2 mA?h/g, and it added retained 85.3% of its initial discharge capacity, while it is only 60.7% after 85 cycles for the one operated with the same basic electrolyte but without additive.

Key words: high-voltage electrolyte, lithium oxalyldifluoroborate, fluoroethylene carbonate, Li-ion battery, LiNi0.5Mn1.5O4