Graphene oxide with improved electrical conductivity for supercapacitor electrodes

Predominant few-layer graphene (FLG) sheets of high electrical conductivity have been synthesized by a multi-step intercalation and reduction method. The electrical conductivity of the as-synthesized FLG is measured to be ∼3.2 × 104 S m−1, comparable to that of pristine graphite. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman analysis reveal that the as-synthesized FLG sheets have large areas with single and double layers. The specific capacitance of 180 F g−1 is obtained for the FLG in a 1 M Na2SO4 aqueous electrolyte by integrating the cyclic voltammogram. The good capacitive behavior of the FLG is very promising for the application for next-generation high-performance electrochemical supercapacitors.