UV curable ionogel for all-solid-state supercapacitor

[Display omitted] •Solvent-free in-situ polymerization method for ionogel electrolyte is proposed.•The ionogel exhibited thermal and mechanical stabilities because of hydrogen bond.•The supercapacitor exhibited 93.93 W h kg−1 with 2000.96 W kg−1.•It exhibited excellent flexibility and non-flammable properties. An ionogel electrolyte with polyurethane acrylate (PUA) and 1-ethyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)imide (EMITFSI) is proposed as an all-solid-state supercapacitor operating at 4 V. The ionogel-based electrolyte is manufactured by using a solvent-free in-situ polymerization method. The ratio of EMITFSI to PUA is optimized by maintaining the free-standing membrane and high ionic conductivity. The supercapacitor, which comprises 25 wt% PUA and 75 wt% EMITFSI, exhibits the highest specific capacitance of 150.88 F g−1 at 0.1 A g−1. It also possesses a high specific energy density (93.93 W h kg−1) without sacrificing specific power density (2000.96 W kg−1) at 0.5 A g−1. Furthermore, the ionogel-applied supercapacitor maintains 99% of its specific capacitance (Cs) after 1000 cycles and exhibits remarkable flexibility while maintaining 92% of its Cs after bending 100 times.