Facile synthesis of graphene sheets intercalated by carbon spheres for high-performance supercapacitor electrodes

Abstract The composites of graphene and CS particles (GCS), which were hydrothermally derived from the aqueous solution of glucose with average diameter of 200 nm, were physically mixed and thermally treated at high temperatures in the range of 700–900 °C. All GCS composites possess totally micropores and the GCS treated at 800 °C (GCS@800) have the high specific capacitances of 272.8 and 197.5 F g−1 in a three-electrode cell at the current density of 0.2 and 10 A g−1, respectively, in 6 M KOH aqueous solution, and demonstrated high rate capability and good cycling stability. The excellent electrochemical performance of the GCS@800 electrode is attributed to its structure with porous CSs as spacer between the graphene sheets to prevent the aggregation and restacking of graphene. This work provides an effective and simple technique by integrating CSs and graphene sheets into composite structures for high-performance energy storage devices.