Nitrogen-Immobilized, Ionic Liquid-Derived, Nitrogen-Doped, Activated Carbon for Supercapacitors

To synthesize nitrogen-remained activated carbon (AC) following KOH activation, nitrile-functionalized ionic liquid (IL) that immobilizes nitrogen atoms in the form of aromatic amines, such as graphitic, pyridinic, or pyrrolic nitrogen, was synthesized and used as a carbon precursor. Aromatic amines are more robust in adverse conditions than aliphatic amines. The nitrogen-doped (N-doped) AC was prepared by activating the carbon derived from the nitrile-functionalized IL that acts as both a carbon precursor and a nitrogen-doping source. The N-doped AC had an optimized doped nitrogen and porous structure, and was prepared by controlling the activation conditions. The nitrogen residue in the N-doped AC after KOH activation enhanced electrochemical properties of the N-doped AC. Thus, it is important to use a carbon precursor that includes immobilized nitrogen to effectively prepare the AC after the KOH activation.