Facile synthesis of microporous carbons with three-dimensional honeycomb-like porous structure for high performance supercapacitors

Abstract

Microporous carbons (MPC) with three-dimensional (3D) honeycomb-like porous structure is synthesized by a simple and convenient carbonization method using polyvinyl alcohol (PVA) as carbon source and KOH as both activating agent and template. Benefiting from its large surface area, 3D interconnected honeycomb-like porous structure and high oxygen doping, the MPC-2 electrode exhibits a high specific capacitance of 367 F g−1 at 0.5 A g−1 and excellent electrochemical stability (99.7% of its initial capacitance after 10,000 cycles) in 6.0 M KOH aqueous electrolyte. More importantly, the assembled MPC-2 symmetric supercapacitor shows an energy density of 22.4 Wh kg−1 based on the total mass of active materials of the two electrodes in 1.0 M Na2SO4 aqueous electrolyte, as well as excellent electrochemical stability. Therefore, this work provides an easy, convenient way to design and large-scale produce 3D honeycomb-like porous carbon for high performance supercapacitors.