Nitrogen and fluorine co-doped graphene hydrogel for high-performance supercapacitors

Abstract

In this work, the nitrogen and fluorine co-doped graphene hydrogel (NFGH) with three-dimensional (3D) porous structure was prepared through a simple one-step hydrothermal method using graphene oxide and ammonium fluoride. The interconnected 3D skeleton porous structure synthesized by the self-assembly of graphene can effectively inhibit the agglomeration of graphene, which will provide more diffusion paths for the electrolyte ions. Benefiting from the wettability of nitrogen functional groups, the nitrogen doping effectively reduces the hydrophobicity of electrode caused by the doping of fluorine. Due to the 3D porous structure of NFGH and the incorporation of nitrogen and fluorine, the NFGH exhibits excellent supercapacitive performance. The maximum specific capacitance of NFGH electrode is up to 366 F g−1 in the aqueous electrolyte, and 98% capacitance can be maintained even after 10,000 cycles. These excellent supercapacitive performances demonstrate that the NFGH has a great potential for application in high-performance supercapacitors.