Synthesis of biomass-derived N,O-codoped hierarchical porous carbon with large surface area for high-performance supercapacitor

Developing high-performance electrode by use of abundant natural materials as sustainable precursors is extremely important for promoting the practical application of supercapacitors. Herein, we present a promising strategy to convert biomass, sorghum seeds (SS), into efficient electrode material through pre-carbonization and combined KOH/melamine chemical activation. The derived electrode material possesses ultrahigh specific surface area (2132.1 m(2) g(-1)), abundant hierarchical pores, and rich N, O doping, which are very beneficial for energy storage. Typically, the as-prepared carbon displays a high specific capacitance of 536.7 F g(-1) at 0.5 A g(-1) in 6 M KOH aqueous electrolyte in a three-electrode system. The assembled symmetric supercapacitors offer excellent cycling stability (97.6% retention after 15,000 cycles) and high specific energy (13.8 Wh kg(-1) at specific power of 298.0 W kg(-1)). The study provides a facile, sustainable, and eco-friendly approach to produce hierarchical porous carbon from biomass for high-performance supercapacitors.

Automated summary

This study presents a promising strategy to convert sorghum seeds into efficient electrode material for supercapacitors, achieving high specific surface area, abundant hierarchical pores, and doping elements. The derived carbon displays excellent capacitance and cycling stability, providing a sustainable and eco-friendly approach for high-performance supercapacitors.