N/S Codoped Three-Dimensional Porous Carbons for High-Performance Supercapacitors with Remarkable Rate Performance
Qiuxia Leng, Fulai Tian, Yanyan Yuan, Wei Li
Abstract
Supercapacitors have been extensively used as commercial energy storage devices. However, to date, it has remained a huge challenge to create efficient supercapacitors due to a poor comprehension of the relationship between the pore structure and electrochemical performances of electrode materials. In this work, the fabrication of N/S codoped three-dimensional porous carbons by a two-step method is reported. First, sulfonated graphene oxide (SGO) is reacted with PVA and melamine formaldehyde (MF) resin to form a precursor with 3D cross-linked network structure, and then the precursors are carbonized and activated with KOH. The optimum porous carbon (ASNPC-1) exhibits a superior specific surface area of 3281 m 2 g –1 as well as excellent electrochemical properties. ASNPC-1 offers a prominent specific capacitance of 386.1 F g –1 at the current density of 0.5 A g –1, which displays excellent rate performance with a capacitance retention rate of 61.9% at 50 A g –1 due to the unique porous structure. Furthermore, the assembled symmetric supercapacitor achieves a high energy density of 14.4 Wh kg –1 at a power density of 700 W kg –1 in 6 M KOH. Hence, this work proposes a facile method for developing high-performance supercapacitors, which is expected for applications in the promising field of energy storage.