Synthesis of Porous NiO/Reduced Graphene Oxide Composites for Supercapacitors

This study developed a facile, one-pot chemical reduction method for fabricating nickel oxide (NiO) and reduced graphene oxide (rGO) composite materials. Electrochemical measurements illustrate that the NiO/rGO composite electrode with a weight ratio of 6 : 4 yields a maximum specific capacitance of 461 F g(-1) and a high energy density of 36.0 Wh kg(-1) at the discharge current of 0.21 A g(-1) in 6 M KOH electrolyte. The composite materials were characterized by scanning electron microscopy, atomic force microscopy, X-ray powder diffraction, and transmission electron microscopy, which showed the formation of conducting matrix of rGO sheets in the NiO/rGO composites. The greatly enhanced total specific capacitance suggests the synergistic effects between NiO/rGO and highlights the importance of rational design in developing rGO-based composites for high energy storage applications. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.036207jes] All rights reserved.