One-pot synthesis of nitrogen-doped ordered mesoporous carbon spheres for high-rate and long-cycle life supercapacitors

Nitrogen-doped ordered mesoporous carbon spheres (N-OMCS) were prepared by a facile one-pot soft-templating and one-step pyrolysis method. The as-obtained N-OMCS possesses an average diameter of around 300 nm, a moderate specific surface area of 439 m² g⁻¹ and uniform mesopore size at around 5.0 nm. Owing to the ordered meso-structure and nitrogen doping, the N-OMCS materials, when used as supercapacitor electrodes, delivers a high specific capacitance of 288 F g⁻¹ at a current density of 0.1 A g⁻¹. More remarkably, the N-OMCS electrode shows excellent rate capability with 66% capacitance retention at an ultrahigh current density of 50 A g⁻¹ and outstanding cycling stability with almost no degradation over 25,000 cycles. The work would open up a new avenue to synthesize carbon spheres with mesoporous structure and nitrogen doping for high-performance supercapacitor applications.