能源化学(英文版)

能源化学(英文版) ›› 2020, Vol. 49 ›› Issue (10): 80-88.DOI: 10.1016/j.jechem.2020.01.019

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High-performance PVDF-HFP based gel polymer electrolyte with a safe solvent in Li metal polymer battery

Jing Jiea, Yulong Liua, Lina Conga, Bohao Zhanga, Wei Lua, Xinming Zhangb, Jun Liua, Haiming Xiea, Liqun Suna   

  1. a National & Local United Engineering Laboratory for Power Battery,Department of Chemistry,Northeast Normal University,Changchun 130024,Jilin,China;
    b Department of Materials Science and Engineering,University of California,Davis 95616,CA,United States
  • 收稿日期:2019-12-16 修回日期:2020-01-17 出版日期:2020-10-15 发布日期:2020-12-18
  • 通讯作者: Haiming Xie, Liqun Sun
  • 基金资助:
    J.Jie and Y.Liu are equally contributed to this work.This work was supported by Special fund of key technology research and development projects(20180201097GX,20180201099GX,20180201096GX),Jilin province science and technology department.The R&D Program of power batteries with low temperature and high energy,Science and Technology Bureau of Changchun(19SS013),National Key R&D Program of China(2016YFB0100500),the National Natural Science Foundation of China(21905041),the Fundamental Research Funds for the Central Universities,Project funded by China Postdoctoral Science Foundation,and Natural Science Foundation of the Jilin Province Education department(JJKH20190265KJ).The Fundamental Research Funds for the Central Universities(2412019FZ015).Key Subject Construction of Physical Chemistry of Northeast Normal University.

High-performance PVDF-HFP based gel polymer electrolyte with a safe solvent in Li metal polymer battery

Jing Jiea, Yulong Liua, Lina Conga, Bohao Zhanga, Wei Lua, Xinming Zhangb, Jun Liua, Haiming Xiea, Liqun Suna   

  1. a National & Local United Engineering Laboratory for Power Battery,Department of Chemistry,Northeast Normal University,Changchun 130024,Jilin,China;
    b Department of Materials Science and Engineering,University of California,Davis 95616,CA,United States
  • Received:2019-12-16 Revised:2020-01-17 Online:2020-10-15 Published:2020-12-18
  • Contact: Haiming Xie, Liqun Sun
  • Supported by:
    J.Jie and Y.Liu are equally contributed to this work.This work was supported by Special fund of key technology research and development projects(20180201097GX,20180201099GX,20180201096GX),Jilin province science and technology department.The R&D Program of power batteries with low temperature and high energy,Science and Technology Bureau of Changchun(19SS013),National Key R&D Program of China(2016YFB0100500),the National Natural Science Foundation of China(21905041),the Fundamental Research Funds for the Central Universities,Project funded by China Postdoctoral Science Foundation,and Natural Science Foundation of the Jilin Province Education department(JJKH20190265KJ).The Fundamental Research Funds for the Central Universities(2412019FZ015).Key Subject Construction of Physical Chemistry of Northeast Normal University.

摘要： Poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) based gel polymer electrolytes are widely studied owing to their electrochemical stability and high dielectric constant.However,most gel polymer electrolytes show unsatisfied safety and interface compatibility due to excessive absorption of volatile and flammable liquid solvents.Herein,by using a safe solvent (N-methyl-2-pyrrolidone) with higher boiling (203℃) and flash points (95℃),we initiatively fabricate a flexible PVDF-HFP based gel polymer electrolyte.The obtained gel polymer electrolyte demonstrates a high ionic conductivity of 7.24×10-4 S cm-1,an electrochemical window of 5.2 V,and a high lithium transference number of 0.57.As a result,the synthesized polymer electrolyte exhibits a capacity retention of 70% after 500 cycles at 0.5 C,and a discharge capacity of 86 mAh g-1 even at a high current rate of 10 C for LiFePO4 based Li metal batteries.Moreover,a stable Li plating/stripping for more than 500 h is achieved under 0.1 mAh at both room temperature and 70℃.Our results indicate that the PVDF-HFP polymer electrolyte is promising for manufacturing safe and high-performance Li metal polymer batteries.

关键词: Gel polymer electrolyte, N-methyl-2-pyrrolidone, Interface stability, Li-ion conduction path

Abstract: Poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) based gel polymer electrolytes are widely studied owing to their electrochemical stability and high dielectric constant.However,most gel polymer electrolytes show unsatisfied safety and interface compatibility due to excessive absorption of volatile and flammable liquid solvents.Herein,by using a safe solvent (N-methyl-2-pyrrolidone) with higher boiling (203℃) and flash points (95℃),we initiatively fabricate a flexible PVDF-HFP based gel polymer electrolyte.The obtained gel polymer electrolyte demonstrates a high ionic conductivity of 7.24×10-4 S cm-1,an electrochemical window of 5.2 V,and a high lithium transference number of 0.57.As a result,the synthesized polymer electrolyte exhibits a capacity retention of 70% after 500 cycles at 0.5 C,and a discharge capacity of 86 mAh g-1 even at a high current rate of 10 C for LiFePO4 based Li metal batteries.Moreover,a stable Li plating/stripping for more than 500 h is achieved under 0.1 mAh at both room temperature and 70℃.Our results indicate that the PVDF-HFP polymer electrolyte is promising for manufacturing safe and high-performance Li metal polymer batteries.

Key words: Gel polymer electrolyte, N-methyl-2-pyrrolidone, Interface stability, Li-ion conduction path