Facile synthesis of fluorine-doped graphene aerogel with rich semi-ionic C–F bonds for high-performance supercapacitor application

A three-dimensional (3D) fluorine-doped graphene aerogel (FGA) with rich semi-ionic C–F bonds was synthesized via a facile hydrothermal method and applied as the electrode material in supercapacitor. A porous 3D network structure with a high specific surface area of the FGA has been confirmed by the combination of scanning electron microscopy, transmission electron microscopy and N2 adsorption method. X-ray photoelectron spectroscopy spectra indicated that the FGA was doped predominantly with semi-ionic C–F bonds, which ensured the high electronic conductivity and sufficient electrochemistry active sites of FGA. As a result, the FGA electrode showed a high specific capacity of 279.8 F g−1 at a current density of 0.5 A g−1, which is much better than that of undoped graphene aerogel (UGA, 141.6 F g−1). Even though the current density increased to 10 A g−1, 90.6% of its specific capacitance was retained. The FGA also maintained about 94.3% of the initial capacitance after 5000 cycles at a current density of 0.5 A g−1. Furthermore, the assembled FGA//FGA symmetric supercapacitor presented a high energy density of 26.2 W h kg−1 at a power density of 899 W kg−1. Accordingly, this work offers a facile and efficient approach to produce fluorine-doped graphene materials for high-performance supercapacitor applications.