Rational Construction of Hierarchical Porous Carbon with Ultrahigh Specific Surface Area and Rich Heteroatoms Toward High-Performance Supercapacitors

Abstract

Favourable pore configuration and active heteroatoms contribute significantly to intrinsic electrochemical performance of carbon materials. Herein, N, S co-doped porous carbons are prepared through facile two-step calcination process, in which pre-carbonized chitosan, thiourea and potassium hydroxide are served as carbon source, dopant and activator, respectively. Optimal sample CTK-3 exhibits considerable specific surface area (SSA), remarkable micropore configuration and preeminent heteroatom level. Therefore, it exhibits a remarkable specific capacitance (309.4 F g-1 at 0.5 A g-1), exceptional cyclic stability and good rate capability. Moreover, the symmetrical supercapacitors assembled by CTK-3 yields an ultrahigh energy density of 15.58 Wh kg-1, indicating appealing application potential of the N, S co-doped porous carbon.

Keywords: chitosan, porous carbon, doping, supercapacitors, electrochemistry