Nitrogen and sulfur co-doped activated carbon nanosheets for high-performance coin cell supercapacitor device with outstanding cycle stability

Abstract Herein, we report the utilization of nitrogen and sulfur dual heteroatoms co-doped activated carbon (NSAC) by hydrothermal method for electrochemical supercapacitors. Various NSACs were made by using a fixed amount of activated carbon and changing the amounts of thioacetamide. From NSAC electrodes, the coin cell configuration was fabricated and the overall electrochemical conduct was evaluated by using cyclic voltammetry, galvanostatic charge-discharge, cycle life, and electrochemical impedance methodologies. The outcomes manifest that co-doping sulfur and nitrogen into the AC improves the electrochemical performance. In comparison to pure activated carbon, the optimized NSAC produced a higher specific capacitance value of 417 F g −1 at 0.7 A g −1 and also demonstrated outstanding charge-discharge cycling stability at 7 mA (5 A g −1 ), maintaining 76% of its opening capacitance after 60,000 cycles in the CR2032 device configuration. The impedance studies phase angle value of 85° has added evidence of the NSAC’s good capacitor performance. Thus, we believe this work is suitable for practical applications for energy storage devices. Graphical abstract