Addition of Redox Additive to Ionic Liquid Electrolyte for High-Performance Supercapacitors of N-Doped Graphene Aerogel

Abstract

Even though the electrochemical capacitors could exhibit an impressive specific power as compared to other energy storage systems, their specific energies still limit their superiority in term of battery replacement. Apart from conventional method to improve the specific energy via complex electrode development, here an alternative route to enhance the performance of the N-doped graphene oxide aerogel supercapacitor using a redox active electrolyte was introduced. The effect of ferrocene methanol in 1-butyl-1-methylpyrrolidinium dicyanamide ionic liquid electrolyte as a redox active electrolyte was investigated. The coupling of this new hybrid electrolyte and a unique nanostructure of the N-doped reduced graphene oxide aerogel could exhibit an excellent specific capacitance and specific energy of 112.1 F g-1 and 34.2 Wh kg-1, respectively as compared to 76.7 F g-1 and 23.5 Wh kg-1 of the conventional 1-butyl-1-methylpyrrolidinium dicyanamide ionic liquid electrolyte. These significant improvements are attributed to the enablement of the Faradaic charge transfer contribution within the redox active electrolyte itself. This redox electrolyte could be used in any high-energy supercapacitors.