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

Abstract

Abstract 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.