Hierarchically porous carbon derived from renewable Chingma Abutilon Seeds for high-energy supercapacitors

The cost-effectively biomass-derived porous carbon is highly promising for usage in electrochemical energy storage as the electrode materials. Herein, a series of hierarchically porous carbons with biomass Chingma Abutilon Seeds as the renewable precursor were synthesized via KOH activation and high-temperature carbonization technique. The resulting carbon material possessed an interconnected structure, high specific surface area (120–3566 m² g^?1), hierarchical pores as well as the heteroatom-substituted functional groups. Based on the synergistic effect of the above-mentioned merits, the optimized material exhibited the remarkably electrochemical performance with high specific capacitance (389 F g^?1 at 0.5 A g^?1) and excellent rate stability (72% capacitance retention at 20 A g^?1) in the three-electrode configuration. More significantly, the symmetric two-electrode device assembled in 6 M KOH delivered a high energy density of 39.2 Wh kg^?1 and excellent chemical stability (90% capacitance retention after 10,000 cycles at 5 A g^?1). Such prominent results might provide a new perspective on the value-added application of the renewable biomass resources in the electrochemical field.