Constructing Nitrogen, Selenium Co-Doped Graphene Aerogel Electrode Materials for Synergistically Enhanced Capacitive Performance

In this work, we demonstrate the successful synthesis of nitrogen and selenium co-doping graphene aerogels (NSeGA) by a convenient and scalable approach. It was found that Se is an effective doping element for improving the energy storage performance of graphene. The synergistic effect between N and Se on improving the performance of supercapacitor was also confirmed. The binder-free NSeGA electrode exhibited a high specific capacity of 302.9 F g(-1)at a current density of 1 A g(-1), which is much higher than that of singly Se-doped graphene aerogel (SeGA, 183.92 F g(-1)) and singly N-doped graphene aerogel (NGA, 150.16 F g(-1)). Even though the current density reached up to 10 A g(-1), 90.4 % of its specific capacitance was maintained. The NSeGA also maintained about 94.1 % of the initial capacitance after 12,000 cycles at a current density of 2 A g(-1). Moreover, the constructed NSeGA//NSeGA symmetric supercapacitor showed a high energy density of 26.3 W h kg(-1)at a power density of 900 W kg(-1). Accordingly, as a new type of carbon-based material, NSeGA has a good prospect in the field of supercapacitors.