Larger-scale fabrication of N-doped graphene-fiber mats used in high-performance energy storage

The N-doped graphene fibers mats (NG-FMs) have been fabricated through spinning GO into ethanol solution of hydroxylamine and following thermal treatment. The NG-FMs are flexible and possess pores with the large interior and small entrance. The results of characterization indicate that N has doped into the graphene sheets during the preparation of the fibers, and that the interplanar distance of the graphene sheets in the fibers has almost no change with the increase of the treating temperature. The capacitive properties of the NG-FMs have been investigated by electrochemical method using two-electrode symmetric capacitor test. The results show that the specific capacitance of NG-FMs can reach 188 F g(-1) at scan rate of 5 mV s(-1) and the capacitors assembled by them possess the high-rate capability (the impedance phase angle can reach 45 at 16.5 Hz) and good cycling stability. The energy density and power density of the capacitor can reach to 2.24 Wh kg(-1) and 48.7 kW kg(-1) at discharged current density of 300 A g(-1) (excluding iR drop). (C) 2013 Elsevier B.V. All rights reserved.