Performance of EMIMFSI ionic liquid based gel polymer electrolyte in rechargeable lithium metal batteries

Abstract

Flexible gel polymer electrolytes based on polymer polyethylene oxide, salt lithium bis(fluorosulfonyl)imide and ionic liquid 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide are synthesized. Prepared samples show high thermal stability, high ionic conductivity at room temperature and an electrochemical stability window of ∼3.51 V vs. Li/Li+. Lithium deposition-striping voltage profiles show the formation of a stable solid electrolyte interface. A Li/GPE/LiFePO4 cell was assembled by low cost thermal lamination technique. This cell can deliver 143 mAh g−1 capacity at room temperature at C/20 rate with good discharge efficiency. Use of micro grid mesh type Al current collector in cathode exhibits significant improvement in capacity retention. © 2018 The Korean Society of Industrial and Engineering Chemistry