Suzhou Yifan Pharmaceutical Co., Ltd.

Porous carbons with high specific surface area are critical engineering materials for current electrochemical capacitors (ECs) technology. Controlling the pore size distribution of porous carbons remains a significant challenge as it is a key aspect in many applications. Herein, we synthesized porous carbon as the electrode material of ECs by means of a two-step synthesis procedure using abandoned feathers as carbon precursor and potassium hydroxide as activating agent. The optimal sample (AFHPC-800-1:3) exhibited an ultra-high specific surface area (S_BET) of 3474 m²/g and a huge total pore volume (V_T) of 1.82 m³ g^-1 as well as abundant small mesopores ranging from 2 to 5 nm in size. The ECs based on the AFHPC-800-1:3 electrode exhibited an ultra-high specific capacitance (C_sp) of up to 709F g^-1 at 0.5 A g^-1. More interestingly, a capacitance of 212F g^-1 was retained even at 100 A g^-1, demonstrating excellent high-rate capacitive performance. Furthermore, the symmetrical capacitor yielded an excellent energy density of 35.1 Wh kg^-1 when the specific power density was 625 W kg^-1, substantiating the potential of the small mesopores in promoting the overall capacitance and energy density of electrode materials.

Abstract: 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 biol.-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 sp. 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.%).Exptl. 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 c.d. 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 d. (ED) of the FPCB-750-1:3//FPCB-750-1:3 sym. cell reaches 56 Wh kg^-1 at a power d. (PD) of 720 W kg^-1 in an aqueous electrolyte (1 M Na₂SO₄), meanwhile maintaining a high-class long-term electrochem. 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.Graphical Abstract: [graphic not available: see fulltext]

In this paper, hollow-tubular porous carbons were synthesized from abundant biomass Cycas fluff (CF) through simple carbonization followed by an NaHCO3 mild activation process.