Fabrication and Enhanced Supercapacitive Performance of Fe_(2)N@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 Fe_(2)N@porous carbon fiber composite(Fe_(2)N@PCF)through heat treatment at various temperatures.Fe_(2)N@PCF-800 demonstrates excellent specific capacitance performance(552 F g^(-1) at 1 A g^(-1)).Meanwhile,The AC//Fe_(2)N@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 Fe_(2)N@PCF demonstrate multiple advantages:i)the Fe_(2)N@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 Fe_(2)N 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.