N-doped honeycomb-like porous carbon towards high-performance supercapacitor

Biomass-derived porous carbon with developed pore structure is critical to achieving high performance electrode materials.In this work,we report a grape-based honeycomb-like porous carbon(GHPC)prepared by KOH activation and carbonization,followed by N-doping(NGHPC).The obtained NGHPC exhibits a unique honeycomb-like structure with hierarchically interconnected micro/mesopores,and high specific surface area of 1268 m~2/g.As a supercapacitor electrode,the NGPHC electrode exhibits a remarkable specific capacitance of 275 F/g at 0.5 A/g in a three-electrode cell.Moreover,the NGHPC//NGHPC symmetric supercapacitor displays a high energy density of 12.6 Wh/kg,and excellent cycling stability of approximately 95.2% capacitance retention after 5000 cycles at 5 A/g.The excellent electrochemical performance of NGHPC is ascribed to its high specific surface area,honeycomb-like structure and high-content of pyrodinic-N(36.29%).It is believed that grape-based carbon materials show great potential as advanced electrode materials for supercapacitors.