Fabrication and Enhanced Supercapacitive Performance of Fe2N@Cotton-based Porous Carbon fibers as Electrode Material

With the emergence of supercapacitors (SCs), the creation of bio-based electrode materials has grown in significance for the advancement of energy storage. However, it is particularly difficult for cathode materials to meet the demands of practical uses due to their low energy density. Herein, MIL-88 was fabricated in situ on the surface of cotton fibers used in cosmetics, followed by creating Fe₂N@porous carbon fiber composite (Fe₂N@PCF) through heat treatment at various temperatures. Fe₂N@PCF-800 demonstrates excellent specific capacitance performance (552 F g⁻¹ at 1 A g⁻¹). Meanwhile, The AC//Fe₂N@PCF-800 device exhibits the largest energy density of 38 Wh kg⁻¹ at 800 W kg⁻¹ and a long cycling stability (83.3% capacity retention after 6000 cycles). Our elaborately designed Fe₂N@PCF demonstrate multiple advantages: i) the Fe₂N@PCF-800 shows abundant mesopores, providing abundant ion-diffusion pathways for mass transport and rich graphite microstructures, improving electrical conductivity for electron transferowning; ii) the rich nitrogen dopants and Fe₂N structure within all carbon components increase the capacitance through their pseudocapacitive contribution. These findings highlight the importance of biomass derived carbon materials for SCs applications.