A new solid-state electrolyte based on polymeric ionic liquid for high-performance supercapacitor

As a polymer host, one polymeric ionic liquid poly(methyl methacrylate-1-vinyl-3-ethyl-imidazolium bis(trifluoromethylsulfonyl) imide) (abbr. P(MMA-co-VEImTFSI)) was successfully synthesized and characterized. Four poly(vinylidene fluoride-co-hexafluoropropylene) (abbr. PVDF-HFP)-based polymer electrolytes were prepared by blending 0, 5,15, and 25 wt% P(MMA-co-VEImTFSI). The electrochemical performances of the prepared electrolytes were studied carefully. The results revealed that increasing the polymeric ionic liquid content, the ionic conductivity of the polymer electrolytes could be enhanced and it obeyed the Arrhenius rule. The highest ionic conductivity of the polymer electrolytes was up to 2.09 × 10−3 S cm−1 at room temperature. The polymer with 25 wt% polymeric ionic liquid showed an excellent electrochemical performance for supercapacitor electrolyte. After 2000 cycles, the retention of capacitance in P(MMA-co-VEImTFSI)-based polymer electrolyte was above 80%. It implied that the present P(MMA-co-VEImTFSI) polymeric ionic liquid was a decent component candidate in the high-performance polymer electrolytes.