Comparative study of NiO based core-shell nanocomposites to high performance supercapacitor electrode materials

In this research work, we prepared NiO@SnO₂ (N1), NiO@ZnO (N2) and NiO@MnO₂ (N3) core-shell nanocomposites using sol-gel route. Prepared samples were investigated for their different properties employing various characterization techniques. The morphology and structure of the nanocomposites were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform Infrared Spectroscopy, X-ray diffraction analysis. Furthermore, the optical properties were analyzed using UV–Vis Spectroscopy, Photoluminescence Spectroscopy. In addition, the supercapacitive performances were examined by cyclic voltammogram (CV), galvanostatic charge-discharge(GCD) and electrochemical impedance spectroscopy (EIS). The electrochemical results indicate that all the prepared composites exhibits good electrochemical performance but N2 depicts superior results among all. The specific capacitance obtained for N2 is 720 F/g at 1 A g⁻¹ and excellent cycling stability (96.5 % retention after 6000 cycles at 1 A g⁻¹). Therefore, this wok offers meaningful reference for supercapacitor applications in the future.