Nature-inspired porous multichannel carbon monolith:Molecular cooperative enables sustainable production and high-performance capacitive energy storage

The advancement of supercapacitors(SCs)is closely bound up with the breakthrough of rational design of energy materials.Freestanding and thick carbon(FTC)materials with well-organized porous structure is promising SC electrode delivering high areal capacitive performance.However,controllable and sustainable fabrication of such FTC electrode is still of great challenges.Inspired by natural honeycombs with cross-linked multichannel structure,herein,an innovative molecular-cooperative-interaction strategy is elaborately provided to realize honeycomb-like FTC electrodes.The nitrogen-doped porous carbon monolith(N-PCM)is obtained with advantages of interconnect pore structure and abundant nitrogen doping.Such strategy is based on naturally abundant molecular precursors,and free of pore-templates,expensive polymerization catalyst,and dangerous reaction solvent,rendering it a sustainable and cost-effective process.Systematic control experiments reveal that strong interactions among molecular precursors promise the structural stability of N-PCM during carbonization,and rational selection of molecular precursors with chemical blowing features is key step for well-developed honeycomb-like pore structure.Interestingly,the optimized sample exhibits hierarchical pore structure with specific surface area of 626.4 m^(2)g^(-1)and rational N-doping of 7.01 wt%.The derived SC electrode with high mass loading of 40.1 mg cm^(-2)shows an excellent areal capacitance of 3621 mF cm^(-2)at 1 mA cm^(-2)and good rate performance with 2920 mF cm^(-2)at 25 mA cm^(-2).Moreover,the constructed aqueous symmetric SC and quasi-solid-state SC produce high energy densities of 0.32 and 0.27 mWh cm^(-2),respectively.We believe that such a composition/microstructure controllable method can promote the fabrication and development of other thick electrodes for energy storage devices.