Disulfide Bonds Reinforced Self‐Assembly of Cellulosic Wastes Toward N/S‐Enriched 3D Carbon Foams with Starfish‐Like Networks for High‐Performance Supercapacitors

Abstract Developing high‐performance electrodes derived from cellulosic wastes is an effective strategy for promoting large‐scale energy storage and achieving carbon neutrality, yet how to enhance capacitive activity from the perspective of surface‐interface structure regulation remains a challenge. Herein, a disulfide bond reinforced self‐assembly of cellulosic wastes strategy is demostrated to fabricate 3D carbon foams with thiram and bio‐straws as examples. The cellulose‐enriched piths of straws (EP) are impregnated with thiram solution followed by pyrolysis, where thiram can form a stable 3D cross‐linked networks via disulfide‐centered hydrogen bonds reinforced self‐assembly of EP and thiram, endowing the obtained starfish‐like skeleton connected 3D carbon foams with high N/S contents and hierarchical porous structure. Consequently, The resultant EPCF‐800 as a binder‐free and conductive agent‐free electrode achieves an ultrahigh specific capacitance of 342 F g −1 in aqueous electrolyte at 0.5 A g −1 , meanwhile, DFT calculations reveal that the high‐level N/S‐doping can effectively weaken the adsorption barriers of K‐ions. Moreover, the EPCF‐800 assembles flexible solid‐state supercapacitors delivering a high energy density of 30.11 Wh kg −1 and a long cycle‐life. This work will shed light on the value‐added utilization of cellulosic wastes from surface‐interface engineering and molecular chemical engineering to pave the way for fabricating high‐performance supercapacitors.