Facile preparation of nitrogen-doped hierarchical porous carbon derived from lignin with KCl for supercapacitors

In this work, a nitrogen-doped lignin-derived hierarchical porous carbon material (LDMCN-700–2) was synthesized by a facile and green strategy using alkali lignin as carbon source, melamine as nitrogen source, and KCl as salt template. The as-prepared LDMCN-700–2 possessed unique structural properties such as a large surface area of 1012.5 m 2 ·g −1 , high nitrogen content of 4.5 at%, and hierarchical porous structure with micropores, mesopores and macropores, which endow it with superior electrochemical performance. The electrochemical measurements demonstrated that LDMCN-700 as an electrode material exhibited a high specific capacitance of 245 F·g −1 at 0.5 A·g −1 , as well as excellent cycling stability with 95.7 % capacitance retention after 5000th cyclic voltammetry cycles, indicating its great potential for supercapacitors. • A lignin-derived nitrogen-doped hierarchical porous carbon material was synthesized. • The synthetic route is facile, green, scalable and cost-effective. • Hierarchical porosity and N-doping synergistically enhanced the whole capacitance. • It exhibited excellent electrochemical performance.