Synthesis and characterization of ZnCo₂O₄ nanomaterial for symmetric supercapacitor applications

Abstract

ZnCo₂O₄ nanomaterial was prepared by co-precipitation method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge–discharge tests at various current densities. It is shown that the crystal structure and surface morphology play an important role in the enhancement of the specific capacitance. The TEM results clearly indicate that the prepared material shows aggregated particles. The particle size powder was about 50 nm, and SEM pictures indicate a porous morphology. The electrochemical behavior of ZnCo₂O₄ was characterized by mixing equal proportion of carbon nanofoam (CNF). From CV, it is concluded that the combination of redox and pseudo-capacitance increases the specific capacitance up to 77 F g⁻¹ at 5 mV s⁻¹ scan rate. The ZnCo₂O₄-based supercapacitor cell has good cyclic stability and high coulombic efficiency.