Synthesis of Highly Uniform N-Doped Porous Carbon Spheres Derived from Their Phenolic-Resin-Based Analogues for High Performance Supercapacitors

A novel route is developed to synthesize highly uniform N-doped porous carbon spheres (NCS) with a tailorable size ranging from 86 to 205 nm depending on their precursors of phenolic-resin-based analogues. Solid-state NMR and FTIR spectra confirm that the as-synthesized polymer spheres are composed of typical phenolic resin. After activation treatment with KOH, the NCS with a diameter of 86 nm possesses a high surface area of 1462 m2 g–1 coupled with hierarchical (micro and meso) pore structures. Upon these advantages, the prepared carbon sample endows the supercapacitor with high specific capacitance up to 247 F g–1 at 1 A g–1 with excellent rate performance and high cycling stability. Also, the specific energy density is 6.74 Wh kg–1 at a current density of 0.1 A g–1. Therefore, the as-prepared uniform N-doped porous carbon spheres represent a promising candidate for an efficient electrode material.