储能科学与技术 ›› 2017, Vol. 6 ›› Issue (1): 101-107.doi: 10.12028/j.issn.2095-4239.2016.0033

• 研究开发 • 上一篇    下一篇

新型锂盐氟代磺酰亚胺锂电解液对锂离子电池性能的影响

李  萌1,2  邱景义1,2  张松通1,2  余仲宝1,2  饶  蕾3  廖红英4   

  1. 1中国人民解放军防化研究院，2先进化学蓄电技术与材料北京市重点实验室，北京 100191；3广东产品质量监督检验研究院，广东 广州 510330；4北京化学试剂所，北京 102607
  • 收稿日期:2016-06-29 修回日期:2016-08-03 出版日期:2017-01-03 发布日期:2017-01-03
  • 通讯作者: 余仲宝，高级工程师，研究方向为锂二次电池单体及其系统集成，E-mail：zhongbaoyu1@sina.com。
  • 作者简介:李萌（1988—），女，助理研究员，研究方向为锂离子电池及其关键材料，E-mail：limengfighting@163.com；

The effect of lithium bis(fluorosulfonyl)imide salt on the performance of Li-ion battery

LI Meng1,2, QIU Jingyi1,2, ZHANG Songtong1,2, YU Zhongbao1,2，RAO Lei3, LIAO Hongying4   

  1. 1Research Institute of Chemical Defense, 2Beijing Key Laboratory of Advanced Chemical Energy Storage Technology and Materials, Beijing 100191, China; 3Guangdong Testing Institute of Product Quality Supervision, Guangzhou 510330, Guangdong , China; 4Beijing Institute of Chemical Reagents, Beijing 102607, China
  • Received:2016-06-29 Revised:2016-08-03 Online:2017-01-03 Published:2017-01-03

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摘要： 采用新型锂盐双（氟代磺酰）亚胺锂（LiFSI）代替六氟磷酸锂（LiPF6）作为锂离子电池的电解液锂盐，配制不同浓度的LiFSI/EC+EMC+DMC（质量比1∶1∶1）电解液，用循环伏安、电化学阻抗（EIS）、恒流充放电等实验并结合Li+迁移数、电导率和黏度等物化参数的测试，研究新型锂盐浓度和电解液物化参数对电池倍率性能的影响。结果表明与同浓度的LiPF6电解液相比，LiFSI电解液具有更高的离子传导能力和电导率及锂离子迁移数；在0.8～1.6 mol/L的浓度范围内，含LiFSI电解液的电池相对含LiPF6电解液的电池表现出更好的电化学性能，更适用于高性能锂离子电池；1.2 mol/L为LiFSI电解液的最优浓度，此时其电导率和锂离子迁移数均达到最大值（=12.39 ms/cm，t+=0.6327），制备的锂离子电池电化学阻抗最小，倍率性能最佳。

关键词: LiFSI, 锂盐浓度, Li+迁移数, 电导率, 锂离子电池

Abstract: LiPF6 salt was substituted by new salt LiFSI in the electrolyte and comparing researches between them were done. LiFSI/ EC+EMC+DMC (mass ratio was 1∶1∶1) with different concentrations (0.8—1.6 mol/L) were prepared. The effect of lithium salt concentration and electrolyte physicochemical parameters on the rate performance was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy(EIS), galvanostatic charge-discharge testing, along with physicochemical parameters testing of Li+ transference number, conductivity and viscosity. It was found that the electronic conductivity and Li+ transference number of LiFSI electrolytes are both larger than LiPF6 electrolyte with same salt concentration. In the range of 0.8 mol/L to 1.6 mol/L, Li-ion batteries using LiFSI electrolytes show better electrochemical performances than those with LiPF6 electrolytes. The optional concentration of LiFSI electrolyte is 1.2 mol/L, when ionic conductivity and Li+ transference number are both the maximum(=12.39 ms/cm, t+=0.6327). Li-ion batteries with 1.2 mol/L LiFSI electrolyts have best rate performance.

Key words: LiFSI, lithium salt concentration, Li+ transference number, conductivity, Li-ion battery