Porous and high electronic conductivity nitrogen-doped nano-sheet carbon derived from polypyrrole for high-power supercapacitors

Porous yet high electronic conductivity carbon electrodes with high ion-adsorptive surface area and low ion/charge transport resistance are crucial to the realization of high-energy/power supercapacitors but have proved to be very challenging to obtain. Herein, nitrogen-doped nano-sheet carbons were synthesized by direct carbonization and activation of polypyrrole at different temperatures. As the temperature increases from 500 to 900 °C, the specific surface area increases from 187 m−2 g−1 to 1450 m−2 g−1 with abundant mesopore and the doping-nitrogen transfer to more stable donor doping state which can improve its electronic conductivity (up to 26.2 S cm−1). Symmetrical supercapacitors based on this carbon exhibit a high energy density of 45.0 Wh kg−1 at 260 W kg−1 and 22.3 Wh kg−1 as the power density increasing to 38.7 kW kg−1, as well as excellent long-term cycling stability, which can be ascribed to its high surface area for electrolyte ions adsorption, and abundant mesopore and high electronic conductivity for ion and electron fast transfer. The remarkable performances suggest that this carbon material is a promising candidate for high-power output supercapacitor electrode materials.