▎ 摘　　要

Gel electrolytes currently draw considerable interest for flexible supercapacitors. Conventional hydrogel electrolytes find limited suitability at low/high temperatures as they contain immense water. This hinders their application in supercapacitors under a harsh environment. Herein, a novel gel polymer electrolyte (GPE) membrane based on the PVdF-HFP/EMITf/Al(Tf)(3) system is prepared. The optimized GPE membrane exhibits a high ionic conductivity of similar to 1.6 x 10(-3) S cm(-1) at room-temperature with a high value of similar to 0.8 x 10(-3) S cm(-1) retained at a freezing temperature of -20 degrees C. The prepared GPE membrane also offers a wide electrochemical stability window (similar to 5.6-4.2 V) in the temperature range of -20 to 60 degrees C. The supercapacitor cells designed with GPE membrane and graphene nano-platelet electrode display excellent capacitive performance (323.9 F g(-1) at 2 V) and cycling stability (over 50000 cycles) at room-temperature. At -20 degrees C, the supercapacitor cells still maintain promising capacitive performance and outstanding cycling stability. Moreover, the designed flexible supercapacitors also offer remarkable performance under various bending conditions and maintain low-temperature tolerance. Consequently, it is believed that the low-temperature tolerance GPE membrane based on the PVdF-HFP/EMITf/Al(Tf)(3) system possesses potential applications in flexible supercapacitors under harsh environments.