N,S‐Co‐Doped Activated Carbon Prepared by a Thiourea‐Assisted “Cutting” Method and their Application as High‐Performance Supercapacitors

Abstract Biomass has been considered a potential source for preparing carbon materials due to its environmentally friendly and renewable characteristics. In this work, N, S co‐doping activated carbon materials were easily prepared by using rice straw as the carbon source. In addition to being heteroatom source, thiourea can fragment the carbon particles into smaller pieces and create plenty of micropores during the carbonization process. Both theoretical and experimental analyses demonstrate that the incorporation of S and N species into carbon can improve the electrochemical performance of supercapacitors. The as‐made N, S co‐doping activated carbon materials, when used as electrodes, exhibit a high specific capacitance of 256 F g −1 at a current density of 1 A g −1 and maintain a good rate capacitance of 65 % even at a high current density of 50 A g −1 . This work may offer valuable guidance for the application of rice straw derived carbon in supercapacitors.