Electrochemical performance of quaternary (1-x)ZnMn<inf>2</inf>O<inf>4</inf>/(x)MgFe<inf>2</inf>O<inf>4</inf> solid solution as supercapacitor electrode

Abstract

Novel nano quaternary metals solid solutions from MgFe2O4 and ZnMn2O4 were synthesized using a sol-gel procedure. The development of a solid solution and the formed phase were examined by phase analysis utilizing the X'Pert High Score Plus program and Fourier transform infrared (FTIR) spectroscopy technique. Rietveld analysis of X-ray diffraction data (XRD), scanning electron microscope (SEM/EDS) and transmission electron microscope (TEM) were applied to determine the lattice parameters, crystallite size, different cations distribution and elemental analysis of the formed solid solutions. The measured dielectric properties of obtained solid solutions are found to be affected by the composition ratio (x). The solid solution (1-x)ZnMn2O4/(x)MgFe2O4 samples exhibited a ferroelectric–paraelectric transition at ferroelectric Curie temperature (Tc). The different hopping mechanisms in the different samples were also examined. The electrochemical performance was tested and influence of composition ratio (x) on the cathodic and anodic potential was investigated. The specific capacitance (Cs) value of electrodes depended on the composition ratio (x) beside the type of cations forming oxides. The (0.9)MgFe2O4/(0.1)ZnMn2O4 sample showed the best performance as a supercapacitor material. The outstanding electrochemical property of the (0.9)MgFe2O4/(0.1)ZnMn2O4 electrode was further confirmed by EIS inspection. The super stability of MgFe2O4/ZnMn2O4 solid solution could be attributed to the activation of the solid solution materials during the CV cycling and the synergistic effects.