Synthesis and Properties of MnMoO4⋅H2O Nanosheet Arrays Wrapped by Ni-Co-S Nanosheets for Supercapacitor Application

Structural design plays a crucial role in enhancing the electrochemical performance of electrode materials in the development of energy storage technologies. Supercapacitors have gained attention due to their fast charge-discharge capability, excellent rate capability, and long-term stability. In this study, MnMoO4.H2O nanostructures were successfully grown on the surface of Ni foam using a hydrothermal method. The resulting nanostructures were then wrapped with Ni-Co-S nanosheets. The nanostructures' structure and morphology were analyzed using several techniques, including field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. To investigate the electrochemical behavior of the nanostructures, cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy were employed. The results of the electrochemical tests indicated excellent supercapacitive behavior and appropriate electrode stability during long charge-discharge cycles. This excellent behavior can be attributed to the three-dimensional structure of the nanostructures, which provides fast and easy transport of electrons and ions. In this study, the specific capacitance of the Ni-Co-S/MnMoO4.H2O/NF supercapacitor was found to be 2798 F g–1 at a current density of 2 A g–1. The maximum energy and power densities obtained were 78.1 Wh kg–1 and 758.3 W kg–1, respectively, making this supercapacitor a promising candidate for practical applications in energy storage.