Coprinus Comatus-Based Nitrogen-Doped Active Carbon for High Performance Supercapacitor

Coprinus comatus-based nitrogen-doped activated carbon (N-ACC) is prepared by chemical activation and nitrogen-doped methods. The N-ACC possesses large specific surface areas (976.96 m 2 g − 1 ), high nitrogen contents (11.53 wt.%), and super hydrophilicity. As electrode material for supercapacitors, the N-ACC shows remarkable electrochemical performance, such as 346 F g − 1 maximum specific capacitance at a current density of 1 A g − 1 , which retains 260 F g − 1 even at a high current density of 10 A g − 1 (about 75% capacitance retention) in 2 M KOH aqueous electrolyte. The assembled N-ACC//N-ACC symmetric supercapacitor exhibits energy density of 14.63 Wh kg − 1 at power density of 810 W kg − 1 , and excellent cycling stability with 92% specific capacitance retention after 10000 cycles in the voltage range 0–1.8 V in 0.5 M Na 2 SO 4 aqueous solution. These results indicate that the N-ACC as electrode materials can be used for high performance supercapacitors.