Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (9): 2861.doi: 10.7503/cjcu20210309

• Physical Chemistry • Previous Articles     Next Articles

Synthesis of a Dual-lithium-salt Comb Polymer Electrolyte and Its Electrochemical Performance

YANG Yingjie, ZHANG Xiaorong, SUN Yuxue, LIU Jun(), XIE Haiming()   

  1. National & Local United Engineering Laboratory for Power Battery,Department of Chemistry,Northeast Normal University,Changchun 130024,China
  • Received:2021-05-04 Online:2021-09-10 Published:2021-09-08
  • Contact: LIU Jun,XIE Haiming E-mail:liuj975@nenu.edu.cn;xiehm136@nenu.edu.cn
  • Supported by:
    the Fundamental Research Funds for the Central Universities, China(2412019FZ015);the Natural Science Foundation of the Jilin Province Education Department, China(JJKH20201168KJ)

Abstract:

Polyethylene glycol monomethyl ether(MPEG) was grafted on poly(isobutylene-alt-maleic anhydride)(PIAMA) to synthesize comb-like lithium mono-ion conductor PIAMA-g-MPEG, which was mixed with lithium bis (trifluoromethylsulfonyl)imide(LiTFSI) to form double-lithium-salt comb polymer electrolyte membrane. Nuclear magnetic resonance(1H NMR) spectroscopy, thermogravimetric analysis(TG), scanning electron microscopy(SEM), electrochemical impedance(EIS) and battery charge-discharge test were used to study the physical, chemical and electrochemical properties of polymer matrix and electrolyte. The results show that the designed double lithium salt comb polymer electrolyte can effectively dissociate and transport lithium ions, the ion mobility tLi+ is 0.32 at 70 ℃, the ion conductivity (σ) is 1.5×10-4 S/cm, the electrochemical stability window is 0—4.9 V(vs. Li/Li+). The assembled Li|PIAMA-g-MPEG|Li battery and the constant current charge-discharge voltage polarization test at 70 ℃ show that the electrolyte has good compatibility with the metal lithium negative electrode and can effectively inhibit the growth of lithium dendrites. The assembled LiFePO4|PIAMA-g-MPEG|Li battery was subjected to 70 ℃ long cycle and rate performance test, and the electrolyte showed excellent high temperature performance.

Key words: Solid polymer electrolyte, Comb polymer, Poly(isobutylene-alt-maleic anhydride), Double lithium salt

CLC Number: 

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