Dung beetle forewing-derived nitrogen and oxygen self-doped porous carbon for high performance solid-state supercapacitors

Commercial supercapacitors are primarily assembled using carbon materials and biomass-derived carbon is one of the most promising carbon materials in the field of supercapacitors. To meet the growing market demand for energy storage devices, a dung beetle forewing-derived carbon (DBFC) material is first prepared using simple a pyrolysis method. The as-prepared DBFC possesses a hierarchical porous structure, nitrogen and oxygen self-doping, and a large surface area. To investigate its electrochemical performance, the DBFC was used to prepare a supercapacitor electrode. A DBFC electrode prepared with a KOH to biomass-derived carbon mass ratio of 3:1 at 700 °C (DBFC-3-700) exhibits a high specific capacitance of 348 F g−1 at 0.5 A g−1 in 6 M KOH liquid electrolyte. The DBFC-3-700 electrode was further assembled into a solid-state symmetric supercapacitor that displays a high specific capacitance of 260 F g−1 at 0.5 A g−1, good cycle stability, and excellent rate capability. Furthermore, three solid-state supercapacitors connected in series can successfully power red light-emitting diodes, demonstrating potential applications in the field of portable and wearable devices.