Double perovskite material of highly active, monoclinic, ordered Ni2ZnMoO6 for an effective quasi-solid state supercapacitor

In the present study, monoclinic Ni2ZnMoO6 double perovskites (monoclinic NZMO DP) electrodes were synthesized using hydrothermal method for supercapacitors application. The structural, elemental, vibrational, and optical characterization were analyzed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy Dispersive X-ray analysis (HR-SEM & EDX), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), Fourier Transform Infrared spectroscopy(FTIR) and UV-Visible Diffusion reflectance Spectroscopy (UV-DRS). A monoclinic structure with a space group of P 2/m and lattice parameters of a =11.4377, b = 9.2961, c = 6.8301, and beta = 97.710 was fitted using Rietveld refinement, and the cell volume was 719.6458 angstrom 3. The surface area of monoclinic NZMO DP was found to be 50.45 m2 g-1 with a pore volume of 0.15 cm3 g-1. Electrochemical characterization was done using Cyclic voltammetry (CV), Electrochemical Impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) measurements. An equivalent-circuit model R(CR)(CR) is iterated to interpret the EIS responses. The Rct found to be less than 100 ohms in the present study can be attributed to Mott variable range hopping (VRH) conduction. The GCD analysis of ASC monoclinic NZMO DP//AC in 6 M KOH at 0.5 Ag-1 in the potential window of 0-1.6 V yields a maximum specific capacitance of 160.45 Fg-1. Excellent electrochemical stability of the monoclinic NZMO DP was ascertained by the specific capacitance retention of the electrode material at 91.37 % after 6000 cycles. The ASC-NZMO monoclinic DP shows an excellent power density of 646.25 W/kg with an energy density of 20.53 Wh/kg. The excellent power storage efficiency and application possibilities of supercapacitors make them a promising technology in various fields.