Amine-Mediated Cosolvent Polymerization for Tunable Mesoporous-Microporous Double-Shell Carbon Spheres toward High-Performance Supercapacitors

Porous carbon materials attract great interest due to their wide range of applications in electrochemical energy systems, especially in structured and pore size-tunable carbon materials prepared by template-assisted methods. In this study, a solvent-mediated polymerization-induced self-assembly strategy is designed for the synthesis of hierarchical double-shell-layer porous carbon nanospheres, and screened out the carbon nanospheres N-doped hierarchical meso-microporous carbon spheres (NPCS)-40 with the best morphology and performance by exploring the effects of different 1,3,5-trimethylbenzene contents, different cosolvent ratios, different cosurfactant ratios, as well as different ethylenediamine and resorcinol contents on the carbon nanospheres’ structure. The resulting carbon nanospheres exhibit a specific capacitance of 249 F g −1 in a supercapacitor with a current density of 0.5 A g −1 and 139.4 F g −1 in a symmetric supercapacitor with excellent stability, which is maintained at 117% after 5000 charging and discharging cycles. Graphical Hierarchical double-shell carbon spheres (N-doped hierarchical meso-microporous carbon spheres (NPCS)-40) are synthesized via amine-mediated cosolvent polymerization, achieving tunable meso/microporous structures. Optimized ethanol (40 vol%) and surfactant ratios yield hollow, nitrogen-doped spheres with high specific capacitance (249 F g − 1 ) and exceptional cycling stability (117% retention after 5000 cycles). The unique pore architecture enhances ion transport, enabling superior supercapacitor performance.