Facile synthesis and frequency-response behavior of supercapacitor electrode based on surface-etched nanoscaled-graphene platelets

Abstract We report on capacitive properties of functionally-graded porous activated nanoscaled-graphene platelets (aNGNS) prepared via reexfoliation of graphite, and high-energy fragmentation through mixed solvent strategy followed by thermochemical etch-away conversion. aNGNS based symmetric supercapacitor demonstrated excellent specific capacitance of 242 F/g at the current density of 0.5 A/g with a capacity retention of 97.21 % after 1000 cycles. The device shown remarkable energy density of 27.22 Wh/kg at a power density of 230.56 W/kg at constant current density of 0.5 A/g. Moreover, the enormous amount of porosity created via chemical-assisted etching could facilitate minimal ion-diffusion resistance to achieve exceptional specific capacitance.