Fungus bran-derived nanoporous carbon with layered structure and rime-like support for enhanced symmetric supercapacitors

Integrating and utilizing natural resources rationally is an important strategy for sustainable development. Herein, a novel nanoporous carbon material with rime scenery-like support was firstly established, in which waste biomass fungus bran was skillfully selected as the layered structure carbon skeletons for loading carboxymethyl cellulose derived carbon particles. The dual biomass-derived carbon with the aid of activating by KMnO4 has a unique structure and favorable electrical conductivity. The resulting sample also has a high micropore ratio, which is optimum for the formation of double layer in aqueous electrolyte. Profiting from hierarchical nanopore structure and nitrogen self-doping, the optimized carbon electrode exhibited excellent specific capacitance of 407 F g−1 at 0.5 A g−1, remarkable rate characteristic, and superior cycling performance (96.9% remained after 5000 cycles). More importantly, the assembled symmetric supercapacitor exhibited a high energy density of 11.4 Wh kg−1 and outstanding electrochemical performance in aqueous electrolyte, which benefited from well-connected networks and multipath channels. This research realizes the utilization of waste biomass in carbon-based electrodes and offers the basis of preparation method for the next generation of sustainable energy storage devices. The fabricated rime scenery-like nanoporous carbon materials exhibit ultra-high specific capacitance and the symmetric supercapacitor possesses a high energy density and power density.