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

Graphical Double doping : We develop a simple and efficient method to prepare N and Se co-doped graphene aerogel (NSeGA) as binder-free electrodes for supercapacitor applications. The results proved that Se is an efficient doping element for carbon-based materials. Furthermore, benefiting from the synergistic effect between N and Se, the NSeGA electrode shows a high specific capacity of 302.9 F g −1 at 1 A g −1 , and a high capacity retention of >94 % after 12,000 cycles. 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.