Abstract:
In this work, we present the synthesis of low cost carbon nanosheets derived from expanded
graphite dispersed in Polyvinylpyrrolidone, subsequently activated in KOH and finally
carbonized in Ar atmosphere. Interconnected sheet-like structure with low concentration of
oxygen (9.0 at.%) and a specific surface area of 457 m2 g-1 was obtained. The electrochemical
characterization of the carbon material as supercapacitor electrode in a 2-electrode
configuration shows high specific capacitance of 337 F g-1 at a current density of 0.5 A g-1 as well
as high energy density of 37.9 Wh kg-1 at a power density of 450 W kg-1.This electrical double
layer capacitor electrode also exhibits excellent stability after floating test for 120 h in 6 M KOH
aqueous electrolyte. These results suggest that this activated expanded graphite (AEG) material
has great potential for high performance electrode in energy storage applications.
