N-doped activated carbon sheets (NACS) have been successfully synthesized using glucose as carbon source via melamine-assisted chemical blowing and sequent KOH-activation method. The obtained carbon material possesses a sheet-like morphology with ultrathin thickness, hierarchical micro/mesoporous structure, high specific surface area (up to 1997.5 m(2) g(-1)) and high pore volume (0.94 cm(3) g(-1)). Besides, NACS material with a nitrogen content of 3.06 wt% presents a maximum specific capacitance of 312 F g(-1), at a current density of 0.5 A g(-1) in 6 M KOH aqueous electrolyte due to the cocontribution of double layer capacitance and pseudocapacitance. It also displays good rate performance (246 F g(-1) at 30 A g(-1)) and cycle stability (similar to 91.3% retention after 4000 galvanostatic charge-discharge cycles). The assembled NACS-based symmetric capacitor exhibits a maximum energy density of 20.2 Wh kg(-1) at a power density of 448 W kg(-1) within a voltage range of 0-1.8 V in 0.5 M Na2SO4 aqueous electrolyte. Thus, the unique porous sheet structure and nitrogen-doping characteristic endue the electrode material a potential application for high-performance supercapacitors. (C) 2016 Elsevier B.V. All rights reserved.