Preparation and characterization of flower-like microspheres of nano-NiO as electrode material for supercapacitor

NiO electrode material was prepared by a facile and environment-friendly hydrothermal method combined with subsequent calcination. The prepared samples were characterized by SEM, XRD and nitrogen adsorption. The electrochemical performances were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge and cycle life. The condition of synthesis on the electrochemical performance of NiO was studied. The results show that the prepared NiO is a nanosize material with a special morphology of flower-like microspheres. It has a high specific capacitance of 762 F g−1 at 1 A g−1 and 598 F g−1 at high discharge current density of 10 A g−1. Furthermore, it exhibits an outstanding cycling performance and stability reflected by a high capacitive retention of 96% after the subsequent 1000 cycles at a high current density of 15 A g−1.