Facile Synthesis of N-Doped Mesoporous Graphitic Carbon for High-Performance Zn Ion Hybrid Supercapacitor

Abstract

Ordered mesoporous carbons (OMCs) are promising materials for cathode materials of Zn ion hybrid supercapacitor (Zn HSC) due to their high surface area and interconnected porous structure. To enhance the energy storage performance of OMCs, graphitization of the framework and nitrogen doping have been employed to improve electrical conductivity, provide pseudocapacitive reaction sites, and increase surface affinity toward aqueous electrolytes. Thus, combining these two methods could further enhance the performance of Zn HSCs. In this study, I introduce a facile synthetic method for N-doped mesoporous graphitic carbon (N-mgc) by using polystyrene-block-poly(2-vinlypyridine) copolymer (PS-b-P2VP) as both the soft-template and the carbon/nitrogen source. Co- assembly of PS-b-P2VP with nickel precursors for graphitization formed a mesostructured composite, which was subsequently converted to N-doped graphitic carbon through catalytic pyrolysis. After selective removal of nickel, N-mgc was prepared. The resulting N-mgc exhibited interconnected mesoporous structure with a high nitrogen content and large surface area. When N-mgc was used as a cathode material in Zn ion HSC, outstanding energy storage performance was achieved: a high specific capacitance (43 F/g at 0.2 A/g), high energy density of 19.4 Wh/kg at a power density of 180 W/kg, and reliable cycle stability (>3000 cycles). These results indicate the potential of N-mgc as an efficient cathode material for high-performance Zn ion hybrid supercapacitors.