A flexible polyelectrolyte-based gel polymer electrolyte for high-performance all-solid-state supercapacitor application

A simple polymerization process assisted with UV light for preparing a novel flexible polyelectrolyte-based gel polymer electrolyte (PGPE) is reported. Due to the existence of charged groups in the polyelectrolyte matrix, the PGPE exhibits favorable mechanical strength and excellent ionic conductivity (66.8 mS cm−1 at 25 °C). In addition, the all-solid-state supercapacitor fabricated with a PGPE membrane and activated carbon electrodes shows outstanding electrochemical performance. The specific capacitance of the PGPE supercapacitor is 64.92 F g−1 at 1 A g−1, and the device shows a maximum energy density of 13.26 W h kg−1 and a maximum power density of 2.26 kW kg−1. After 10 000 cycles at a current density of 2 A g−1, the all-solid-state supercapacitor with PGPE reveals a capacitance retention of 94.63%. Furthermore, the specific capacitance and charge–discharge behaviors of the flexible PGPE device hardly change with the bending states.