NiMoO4@NiWO4 honeycombs as a high performance electrode material for supercapacitor applications

Abstract

In this study, we report a facile two-step fabrication of honeycomb-like NiMoO₄@NiWO₄ nanocomposites on Ni foam as the electrode for high-performance supercapacitor applications. Structural characterization and compositional analysis of the as-prepared NiMoO₄@NiWO₄ nanocomposites was performed using scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammetry, galvanostatic charge–discharge cycling, and electrochemical impedance spectroscopy. The electrochemical properties of the as-synthesized NiMoO₄@NiWO₄ nanocomposites were studied in a 3 M KOH electrolyte solution for application as electrode material of supercapacitors. A maximum specific capacitance of 1290 F g⁻¹ was achieved for NiMoO₄@NiWO₄ at a current density of 2 A g⁻¹. This electrode exhibits excellent long cycle-life stability with 93.1% specific capacitance retention after 3000 cycles at a current density of 6 A g⁻¹. Our studies indicate that the as-synthesized NiMoO₄@NiWO₄ nanocomposites could be a promising candidate as the electrode material in high-performance electrochemical energy storage applications.