Biomass porous carbon-based composite for high performance supercapacitor

Abstract

Biomass porous carbons with abundant pore structure, surface functional groups, and excellent electrical conductivity, are widely used for electrode materials. In this work, biomass carbon with 3D mesh structure was loaded with metal sulfide to synthesize porous carbon-based ultrathin Ni3S2 layered nanosheet structure supercapacitor composite material electrode. C/Ni3S2-16 showed 600 F g−1 of high specific capacitance with 20 A g−1 current density. After 5,000 charge and discharge cycles, 88.8% of the maximum (imital) specific capacitance was maintained at 10 A g−1. The assembled C/Ni3S2-16//C asymmetric supercapacitor achieved an energy density of up to 35.7 Wh Kg−1, which was remained at 27.9 Wh Kg−1 with a high power density at 1500 W kg−1. Developed pore structure of biomass porous carbon provide sufficient space for the electrolyte in and out of the electrode, therefore the potentially high electrochemical activity and energy density of the transition metal sulfide were fully exhibited.