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

Abstract

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 nitrogen‐doping (i. e., by applying a synthesis temperature of 800 °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.