Multi-heteroatom-doped hierarchical porous carbon derived from chestnut shell with superior performance in supercapacitors

Biomass-derived porous carbon materials hold good prospects for application in supercapacitor owing to their natural abundance, low cost, as well as high heteroatoms content. Herein, multi-heteroatom-doped hierarchical porous carbon was prepared via on-step carbonization process by using chestnut shells as raw material and melamine as activation agent. The obtained chestnut shell-derived carbons exhibit a high specific area (691.8 m2 g−1), abundant interconnected micropores/mesopores, proper level of graphitization, considerable content of heteroatoms (∼3.79 at. % N, ∼13.35 at. % O, and ∼0.52 at. % S). Benefiting from these superior characteristics, the obtained carbon electrode exhibits a high specific capacitance (402.8 F g−1 at 0.5 A g−1 in a three-electrode system) and outstanding rate capability (45.3% capacitance retention at 100 A g−1) in KOH electrolyte. The fabricated symmetric supercapacitor delivers a superior energy density of 26.6 Wh kg−1 at a power density of 445.5 W kg−1. In addition, the supercapacitor device shows good cycling stability with a 96.6% capacitance retention after 20,000 cycles. These results demonstrates that the as-prepared carbonaceous materials have great potential for low-cost and high-performance supercapacitors.