K₂FeO₄-Assisted Preparation of Discarded Badminton Shuttlecock Feather-Derived Hierarchical Porous Carbon for High-Performance Supercapacitors

Biomass waste carbon sources enjoy a place of pride because of their low-cost, environmentally friendly, and readily available nature. The development of an efficient approach to transform biomass wastes into functional carbon-based electrode materials is a hot topic. However, the production process of biologically-based activated carbon needs to be further improved. Here, discarded badminton shuttlecock feathers were used as precursor via activation with potassium ferrate (K₂FeO₄) to prepare hierarchical porous carbon. The obtained carbon material with hierarchical pore structure displays a high specific surface area (S_BET) of 1279.5 m² g⁻¹, large total pore volume (V_total) of 0.73 cm³ g⁻¹ ,and high-level hetero-atom doping (N: 3.78 at.%, O: 7.5 at.%, S: 3.85 at.%). Experimental results reveal that the as-prepared FPCB-750–1:3 exhibits an excellent specific capacitance (C_g) of up to 449 F g⁻¹ at the current density of 0.1 A g⁻¹. Moreover, even at 10 A g⁻¹, the FPCB-750–1:3 electrode still presents a high capacitance of 216 F g⁻¹. In addition, the energy density (ED) of the FPCB-750–1:3//FPCB-750–1:3 symmetric cell reaches 56 Wh kg⁻¹ at a power density (PD) of 720 W kg⁻¹ in an aqueous electrolyte (1 M Na₂SO₄), meanwhile maintaining a high-class long-term electrochemical stability (fading lower than 4% after 10,000 cycles of charging and discharging). This study provides a trustworthy method to produce promising electrode materials from waste biomass for high-performance supercapacitors.