A study on the preparation of polycation gel polymer electrolyte for supercapacitors

The polycation gel polymer electrolyte (PGPE) is a promising electrolyte material for supercapacitors due to its high ionic conductivity and great flexibility. Herein, we report a novel flexible PGPE film, which is prepared by thermal copolymerization. The superiority of PGPE is attributed to the existence of charged groups in the polymer skeleton. Consequently, the crystallinity of the polymer is effectively reduced, and the migration of the lithium ion is evidently promoted. Moreover, the liquid retention capacity of the film is improved, which enhances its ionic conductivity as well. The reported PGPE exhibits a high ionic conductivity of 57.6 mS cm^-1 at 25 °C and a potential window of 0-1.2 V. The symmetrical PGPE supercapacitor (AC/AC) shows 95.21% mass-specific capacitance retention after 5000 cycles at 2 A g^-1 with a maximum energy density of 12.8 W h kg^-1 and a maximum power density of 5.475 kW kg^-1. This study confirms the exciting potential of PGPE for high performance supercapacitors.