Foaming waste wine yeast mud into nitrogen doped porous carbon framework by recyclable activator for high specific energy supercapacitor

Biomass-derived carbon materials have received extensive attention in the field of energy storage and conversion due to their renewability, environmental protection, and rich in heteroatoms. Herein, waste wine yeast mud -derived nitrogen doped porous carbon framework (WMCF) has been prepared via a one-step simultaneous activation, foaming and nitrogen doping strategy using the non-toxic and recyclable Na2CO3 as the activating agent. The fabricated WMCF has a large specific surface area (1274.3 m(2 )g(-1)), developed mesopores structure and high nitrogen doping content (7.2 wt%), which significantly improves the electrochemical performance. As an electrode material for supercapacitor, the typical WMCF-2 material exhibits high specific capacitance of 220 F g(-1 )at 0.5 A g(-1) and excellent rate capability (80 % capacitance retention even the current density increases 40 times). Besides, symmetric supercapacitor based on WMCF-2 electrodes and ionic liquid (EMIMBF4) electrolyte exhibits a high energy density of 50.4 W h kg(-1) at 500 W kg(-1 )operated in the voltage range of 4 V, and outstanding capacitance retention of 91 % after an ultra-long 10,0000 cycles. The green preparation of biomass -based porous carbon frameworks offers a promising strategy for realizing low-cost and high energy density supercapacitors.

Automated summary

Biomass-derived carbon materials have attracted significant attention in the field of energy storage and conversion due to their renewability, environmental protection, and high heteroatom content. In this study, nitrogen-doped porous carbon framework (WMCF) derived from waste wine yeast mud was prepared using a one-step activation, foaming, and nitrogen doping strategy. The WMCF exhibited a large specific surface area, developed mesoporous structure, and high nitrogen doping content, resulting in improved electrochemical performance. As an electrode material for supercapacitors, WMCF-2 showed high specific capacitance and excellent rate capability. Moreover, a symmetric supercapacitor based on WMCF-2 electrodes and an ionic liquid electrolyte exhibited high energy density and outstanding capacitance retention.