Preparation and enhanced capacitive behavior of Ni-ZnO nanocomposite as electrode for supercapacitor

The objective of the present work is to evaluate the enhanced capacitive behavior of newly prepared Ni-ZnO nanocomposites as electrode materials for supercapacitor applications. Ni-ZnO nanocomposites have been prepared via sol-gel method. Morphology and structural properties of Ni-ZnO particles have been studied with the help of field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD), respectively. The electrochemical properties of the Ni-ZnO based electrode have been determined by cyclic voltammetry (CV) and galvanostatic charge-discharge tests. Test results obtained from CV test show that maximum specific capacitance for Ni-ZnO based electrodes has been evaluated as 392 F g(-1) at the scan rate of 5 mV s(-1) in 1M Na2SO4 electrolyte. The cycle stability of the Ni-ZnO based electrodes has been probed by using cyclic voltammetry and galvanostatic charge-discharge measurements. The cycle stability test reveals that after 5000 charge-discharge cycles, Ni-ZnO based electrode has lost only 18% capacitance value of that of the initial value. Hence, the as synthesized Ni-ZnO nanocomposites could be reckoned to be a potential candidate for electrode material of supercapacitor. (C) 2019 Elsevier Ltd. All rights reserved.