Sweet Potato-Derived Carbon Nanosheets Incorporate Co3O4 Nanocomposite Films as Electrode Materials for Asymmetric Supercapacitors and Its Electro Chemical Performance

Considering the great potential of composite electrode with carbon and transition metal oxides as a future ideal form of electrode for future energy storing system, many efforts have been devoted into such aspect of research. Sweet potato-derived carbon framework with nanosheet form of Co3O4 nanoparticles anchored on it was carried out through the low-temperature solution grown technique, which is simple, low-cost, and applicable for large-scale commercial production. Structural, morphological and elemental composition of the films was investigated by X-ray diffraction (XRD), Raman, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy and N-2 adsorption-desorption analysis. XRD and TEM results exhibit that both pure and composite samples have nanocrystalline and Co3O4 nanoparticles were uniformly distributed on the surface of sweet potato derived carbon frame work (SPCF). The SPCF derived Co3O4 electrodes have demonstrated enhanced capacitance, with a maximum specific capacitance of 1050 Fg(-1) at 2 mAg(-1), and good cycling stability, retaining about 99.6% of their capacitance after 5000 cycles, as well as improving supercapacitor energy density without sacrificing power density. The maximum as energy density of the porous carbon-cobalt oxide composite supercapacitors was found to be 88.9 Whkg(-1).