Spinel cobalt oxide nanoflakes supported on graphene oxide nanosheets (GO-supported Co3O4) was fabricated via a two-step procedure as a high-performance pseudocapacitive electrode. In the first step, graphene oxide (GO) nanosheets were uniformly deposited on the surface of graphite current collector by electrophoretic deposition (EPD) technique to construct a three-dimensional (3D) conductive GO framework. In the following, cobalt oxide nanoflakes were electrochemically deposited on the surface of GO nanosheets. The structure and morphology of the as-prepared GO-supported Co3O4 hybrid electrode were examined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM). Considering that the obtained 3D open porous structure can effectively facilitate electrons and electrolyte ions transport to the active material, the hybrid electrode exhibits excellent charge storage characteristics including a high specific capacitance of 765 F g−1 at 1 A g−1, good rate capability (62.4% capacitance retention with a tenfold increase in the discharge current density), and superior cycling stability (91.9% of the initial discharge capacitance after 2000 cycles).
