Large-size graphene-like porous carbon nanosheets with controllable N-doped surface derived from sugarcane bagasse pith/chitosan for high performance supercapacitors.

The large-size graphene-like porous carbon nanosheets (LGPCN) with controllable N-doped surface are successfully prepared by using a simple and effective integrated “self-template” and “designing” strategy through KOH activation. Biomass-sugarcane bagasse pith and chitosan are used as self-template carbon source and controlled nitrogen source, respectively. The relationship between structure of the LGPCN-X (X represents the activation temperature) and its electrochemical performance at different activation temperatures is explored in detail. The large-size multiscale wrinkled nanosheets architecture, high surface area, and appropriate controllable surface nitrogen doping state of the LGPCN-800 shows the best electrochemical performance in 6 M KOH. The largest specific electrode capacitance is about 339 F g −1 (at 0.25 A g −1 ), which still as high as 280 F g −1 at 100 A g −1 . The maximum energy density is about 11.77 Wh kg −1 at a power density of 34.11 W kg −1 . The LGPCN-800 also shows an excellent cycling stability with 97.9% capacitance retention after 10,000 cycles. [ABSTRACT FROM AUTHOR]