Nitrogen and Oxygen\nCodoped Hierarchically Porous\nCarbon Derived from Tannic Acid and Reed Straw for High-Performance\nSupercapacitors

The effective utilization of abundant natural biomass-derived\nmaterials\nas sustainable precursors for developing high-performance electrodes\nis of great significance for advancing practical applications of supercapacitors.\nIn this study, we propose an effective strategy to convert biomass\nreed straw and tannic acid (TA) as dual carbon sources into N, O codoped\nhierarchically porous carbon electrode materials with a rich micro/mesoporous\ninterconnected layered structure, denoted as N-RTC-1.5, through cochemical\nactivation of KOH and melamine (MA) and precarbonization. N-RTC-1.5\nexhibits a unique honeycomb-like porous structure with a high specific\nsurface area of up to 2545 m<sup>2</sup>/g. As a supercapacitor electrode,\nN-RTC-1.5 demonstrates an excellent specific capacitance of 366.0\nF/g at 1 A/g in a three-electrode system. Furthermore, the energy\ndensity of an N-RTC-1.5//N-RTC-1.5 symmetric supercapacitor reaches\n18.32 Wh/kg, and after 10000 cycles at 3 A/g, the capacitance retention\nis approximately 96%. This research provides a simple, sustainable,\nand environmentally friendly approach to convert biomass into novel\ncarbon materials required for high-performance supercapacitor electrodes.