Sorghum-derived porous carbon for outstanding green supercapacitors

Exploiting high-performance carbonaceous materials from biomass for supercapacitor (SC) electrodes has attracted extensive attention. In this research, hierarchical porous carbon electrodes derived from sorghum have been explored for the construction of symmetrical supercapacitors. A facile carbonization/activation strategy has been employed to synthesize porous carbon with a large specific surface area (∼1271 m2 g−1), an interconnected hierarchical pore structure, and heteroatom doping such as N, O, P, and S. The supercapacitors show a high specific capacitance of ∼483 F g−1 at 1 A g−1, a high energy density of 96.54 W h kg−1 at a power density of 1200 W kg−1 and cycle stability with capacitance retention of 97.5% after 10 000 charge/discharge cycles. This work presents a promising strategy for fabricating biomass-derived porous carbon with high energy density and low loss for commercial application in energy storage systems.