Facile Synthesis of Hierarchical CuO Nanoflower for Supercapacitor Electrodes

Three-dimensional CuO nanoflowers were prepared on the surface of flexible Cu foil (CuO@Cu) by a chemical deposition method. The morphology and composition of CuO nanoflowers were examined by scanning electron microscopy and x-ray diffraction spectroscopy, respectively. The electrochemical supercapacitive properties of CuO nanoflowers were investigated by cyclic voltammetry, galvanostatic charge-discharge measurements and electrochemical impedance spectroscopy (EIS). Electrochemical tests indicated that the optimized product showed a high specific capacitance of 284.5 F g(-1) at the current density of 0.5 mA cm(-2). EIS analysis indicated that the CuO nanoflowers exhibited good conductivity and very low internal resistance. The cyclability of the electrode demonstrates a 20% loss in capacitance over 1000 cycles. Thus, the results revealed that CuO nanoflower active materials hold the potential for electrochemically stable supercapacitors.