Interlacing Rod and Sphere Morphology of MnO2 in RGO/NiO/MnO2 Ternary Nanocomposites for Supercapacitive Applications


 Supercapacitors are promising energy storage devices. Herein a comparative study was carried out between two samples of reduced graphene oxide-infused binary metal oxides, in which the morphology of one of the metal oxides (Manganese oxide) is altered. MnO2 was synthesized in two morphologies, as nanorods and nanospheres. The two morphologies were separately composited with the as-synthesized cone-structured nickel oxide and sheets of reduced graphene oxide (rGO) and were subjected to various structural, functional, morphological, and electrochemical characterizations etc. The morphologies and structures of the as prepared samples were characterised by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectrometry. The functional properties were determined using Fourier transform infrared spectroscopy. The electrochemical performance of both the samples were analysed using cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy under electrolytes with different pH, namely 1 M Na2SO4(pH=7) and 1 M Na2CO3(pH=11). The main advantage of this work is that the best-suited morphology with better ion transfer rate having commendable electrochemical ability and long-standing cycle rate for a promising supercapacitor is identified which will serve as the reference for future supercapacitor electrode.