Solvent‐Free Mechanochemical Synthesis of Nitrogen‐Doped Nanoporous Carbon for Electrochemical Energy Storage

Nitrogen‐doped nanoporous carbons were synthesized by a solvent‐free mechanochemically induced one‐pot synthesis. This facile approach involves the mechanochemical treatment and carbonization of three solid materials: potassium carbonate, urea, and lignin, which is a waste product from pulp industry. The resulting nitrogen‐doped porous carbons offer a very high specific surface area up to 3000 m 2 g −1 and large pore volume up to 2 cm 3 g −1 . The mechanochemical reaction and the impact of activation and functionalization are investigated by nitrogen and water physisorption and high‐resolution X‐ray photoelectron spectroscopy (XPS). Our N‐doped carbons are highly suitable for electrochemical energy storage as supercapacitor electrodes, showing high specific capacitances in aqueous 1 m Li 2 SO 4 electrolyte (177 F g −1 ), organic 1 m tetraethylammonium tetrafluoroborate in acetonitrile (147 F g −1 ), and an ionic liquid (1‐ethyl‐3‐methylimidazolium tetrafluoroborate; 192 F g −1 ). This new mechanochemical pathway synergistically combines attractive energy‐storage ratings with a scalable, time‐efficient, cost‐effective, and environmentally favorable synthesis.