High performance nitrogen-doped porous graphene/carbon frameworks for supercapacitors

Nitrogen-doped porous graphene/carbon (NPGC) framework electrode materials have been synthesized via chemical activation of graphene oxide/polypyrrole (GOP) composites with KOH. The effects of the mass ratio of KOH/GOP and activation temperature on the electrochemical performance of NPGC have been discussed. It is found that the NPGC prepared by activating GOP (GO : Py = 1 : 40) with 3.5 times mass of KOH at 650 °C (NPGC650) exhibits the highest specific capacitance of 405 F g−1 at a current density of 0.2 A g−1. Particularly, the specific capacitance still remains at 249 F g−1 even at a current density as high as 10 A g−1. Moreover, 96% of the capacitance can be retained after 1000 cycles even under a high operation current of 10 A g−1. The present work provides a novel strategy to synthesize NGPC electrode material for supercapacitors.