Holey graphene oxide as filler to improve electrochemical performance of solid polymer electrolytes

Abstract

Solid polymer electrolytes (SPE) have attracted wide attention of researchers because of their high safety performance and high mechanical strength. In this paper, holey graphene oxide (HGO) was added to poly(ethylene oxide) (PEO) solid polymer electrolytes with lithium bis(trifluoromethane sulfonimide) (LiTFSI) as salt to improve the ionic conductivity of solid polymer electrolytes. It was shown that the addition of holey graphene oxide improved the electrochemical window and ionic conductivity. When the amount of holey graphene oxide was 0 wt%, the ionic conductivity was 2.06 × 10–4 S/cm at 60 °C. In comparison, when the amount of holey graphene oxide was 0.2 wt%, the ionic conductivity was greatly increased to 6.05 × 10–4 S/cm. This was mainly due to the fact that addition of holey graphene oxide reduced the crystallization of polymer and promoted the migration of lithium ion. Meanwhile, the electrochemical window was expanded to 5.2 V and the cycle performance for the batteries was also improved.