N-doped carbon spheres with hierarchical micropore-nanosheet networks for high performance supercapacitors

Abstract

N-doped carbon spheres with hierarchical micropore-nanosheet networks (HPSCSs) were facilely fabricated by a one-step carbonization and activation process of N containing polymer spheres by KOH. With the synergy effect of the multiple structures, HPSCSs exhibit a very high specific capacitance of 407.9 F g⁻¹ at 1 mV s⁻¹ (1.2 times higher than that of porous carbon spheres) and a robust cycling stability for supercapacitors.