Superior performance supercapacitor based on high-value porous carbon microspheres derived from jute fibers with localized graphitic domains (few-layer graphene)

Recently, researchers put lots effort in pursuing high specific surface area of biomass-derived activated carbon for advanced energy storage applications. However, carbon materials with high specific surface area often suffer from low conductivity owing to high porosity. Besides, biomass-derived activated carbon usually exhibits a bulk-like morphology, resulting in low effective adsorption area (severe stacking). In this study, jute fibers-derived porous carbon microspheres with localized graphitic domains (few-layer graphene) are prepared to overcome previously mentioned issues. The spherical morphology eliminates severe stacking effect, and the graphitic domains significantly enhance electrical conductivity. Moreover, the dual functionality of KOH as activating agent (formation of pores and graphitic domains) and biomass-derived carbon microspheres have been rarely discussed in the literatures, showing the novelty and uniqueness of this study. The obtained sample in this study exhibits high specific surface area (1686 m 2 /g), low equivalent resistance (0.51 Ω), exceptional stability (97% capacitance retention after 5000 cycles at 20 A/g) and superior specific capacitance (443 F/g at 0.5 A/g), demonstrating obtained material is a promising material for advanced energy storage applications. The symmetric supercapacitor is also assembled and shows specific capacitance of 202 F/g at 0.5 A/g and delivers energy density of 28.1 Wh/kg at power density of 250 W/kg within 1 V voltage.