NiMoO@NiWO honeycombs as a high performance electrode material for supercapacitor applications.

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.