Nitrogen\nSelf-Doped Porous Carbon for High-Performance\nSupercapacitors

Abstract

Supercapacitor electrodes\nbased on carbonaceous materials with\nhierarchical porosity and localized graphitic structure can help supercapacitors\nto achieve considerable energy capacity. In this work, chitosan-derived\nhierarchically porous graphitic carbon (CS-HPGC) with nitrogen self-doping\nwas synthesized via a simple and green approach using potassium ferrate\n(K₂FeO₄). Different from conventional templating\nor two-step strategies, this method allows the accomplishment of carbonization,\ngraphitization, and heteroatom modification in a one-step process.\nEndowed with the characteristics of hierarchical porosity, high graphitization\ndegree, and N-doping, the CS-HPGC electrode showed a high specific\ncapacitance of 332 F g^–1 at 0.5 A g^–1. Furthermore, the assembled CS-HPGC symmetric supercapacitors delivered\nan energy density of 10.2 Wh kg^–1 at the power density\nof 100 W kg^–1 in aqueous electrolyte (KOH) and 63.3\nWh kg^–1 at 300 W kg^–1 in ionic\nliquid electrolyte (EMIM TFSI). This synthetic strategy may pave the\nway for the development of natural and renewable biomass resources\nfor sustainable energy systems.