Facile Preparation of 3D Nanostructured O/N co-Doped Porous Carbon Constructed by Interconnected Carbon Nanosheets for Excellent-Performance supercapacitors

A facile and readily scalable approach to prepare O/N co-doped 3D nanostructured foam-like porous carbon composed of interconnected carbon nanosheets (NFPCs) has been successfully explored. The NFPCs are synthesized from normal reagents including melamine resin, coal tar pitch, magnesium acetate and KOH, and firstly found that the KOH exerts a vital role in constructing the 3D foam-like nanostructure. The 3D foam-like porous carbon possesses continuous macropores, high surface area, interconnected 8 nm thick carbon nanosheets, especially, a good deal of nanosized fissures in carbon nanosheets and high content of oxygen/nitrogen heteroatoms, which endow NFPCs with superior capacitive performance. The NFPC0.4-0.4Y-700 exhibits a high specific capacitance of 302 F g−1 at 5 A g−1 and high rate capability (92% retention from 5 to 50 A g−1) in 6 M KOH. The NFPC0.4-0.4Y-700 symmetrical supercapacitor has presented a high energy density of 21 Wh kg−1 at 865 W kg−1 in 1 M Na2SO4 electrolyte. The simple, cost-effective and scalable synthesis strategy to produce advanced nanostructured carbon materials from industrialized reagent provides a new protocol for fabricating excellent performance supercapacitors.