All-solid-state supercapacitors with superior compressive strength and volumetric capacitance

Highly dense graphene architectures (DGAs) embedded with solid electrolyte were fabricated by evaporation-induced shrinkage of reduced graphene oxide (rGO) hydrogels filled with phosphoric acid/polyvinyl alcohol electrolyte solution. In such DGAs, rGO sheets remain a stacked structure and solid electrolyte is uniformly distributed throughout the DGAs. The all-solid-state supercapacitors based on DGAs achieved a superior volumetric capacitance of about 155 F cm−3 at 0.1 A g−1. More importantly, the all-solid-state supercapacitors based on DGAs retain stable electrochemical properties under different compressive stresses.86