Morphological transformation of rod-like to pebbles-like CoMoO4 microstructures for energy storage devices

Abstract Effectively electrode materials with optimized morphologies have exposed promising potential in continuous development of supercapacitor electrochemical performance over the past few years. Here, we prepared a novel design of CoMoO4 (CMO) microstructures through hydrothermal/solvothermal method and obtained two different morphologies: rod-like and pebbles-like, respectively. The phase purity, structural characteristics and chemical bonding of the samples were analysed by x-ray diffraction (XRD), Fourier Transform – Infrared (FT-IR) analyses. The morphological characteristics and composition of the samples were examined using Field emission-scanning electron microscopy (FE-SEM) and Energy dispersive x-ray spectroscopy (EDS) analyses respectively. The elemental composition and chemical states of the materials was further evaluated using XPS analysis. Electrochemical behaviour of the two different CMO microstructures was evaluated using Cyclic voltammetry (CV), Galvanostatic charge discharge (GCD), and Electrochemical impedance spectroscopy (EIS) analyses. A high areal capacitance of 1.57F cm−2 for R-CMO and 2.27F cm−2 for P-CMO at 1.5 A cm−2 and superior cycling stability of 90.49% for R- CMO, 85.95% for P-CMO was retained after 2,000 cycles. The unique hierarchical architectures with good structural and electrochemical properties of the materials creates new directions in the emerging field of energy storage applications.