Influence of Nitrogen-Doping for Carbide-Derived Carbons on the Supercapacitor Performance in an Organic Electrolyte and an Ionic Liquid

We investigated the influence of nitrogen groups on the electrochemical performance of carbide-derived carbons by comparing materials with a similar pore structure with and without nitrogen-doping. These materials were tested in a half-cell and full-cell supercapacitor setup with a conventional organic electrolyte (1 M tetraethylammonium tetrafluoroborate in acetonitrile) and an ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate). Varying the nitrogen content in the range of 1-7 mass% had no systematic influence on the energy storage capacity but a stronger impact on the rate handling ability. The highest specific capacitance in a half-cell supercapacitor at a negative potential was 215 F/g in EMIM-BF4. Using the best-performing carbide-derived carbon with and without nitrogendoping (i.e., by applying a synthesis temperature of 800 degrees C), the full-cell performance was 174 F/g, which results in a high specific energy of 61 Wh/kg in EMIM-BF4. For the same materials, the corresponding specific energy was about 30 Wh/kg when using the organic electrolyte.