Realizing high electrochemical performance in layered polycrystalline Ca₃Co₄O₉ oxide

The scientific community working in energy storage has shown considerable interest in materials that include nickel and cobalt, primarily because of their remarkable capacitance properties. In the present case, the electrochemical properties of Ca₃Co₄O₉ bulk material synthesized via solid-state reaction method are explored for supercapacitor applications. X-ray diffraction (XRD) analysis revealed that the samples being examined exhibit a single phase devoid of any secondary phases. The utilization of scanning electron microscopy (SEM) and N₂ adsorption-desorption isotherm curves allowed for a comprehensive morphological investigation. This research demonstrated that the incorporation of Ca₃Co₄O₉ resulted in reduced particle sizes, increased specific surface areas, and enhanced pore volumes. The X-ray photoelectron spectroscopy (XPS) analysis confirms the oxidation states of the elements present in the material. The electrochemical properties were examined by utilizing cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) techniques. Ca₃Co₄O₉ exhibited specific capacitance (C_s) value of 910.17 ± 9.8 F/g at a current density of 1 A/g. The power density is 198.01 ± 4.55 W/kg, while the energy density is 22.04 ± 1.23 Wh/kg. The observed cycling performance exhibited high levels of efficiency, with retention rates of 98.04% and a coulombic efficiency of 99.01% after undergoing 2000 cycles. Ca₃Co₄O₉ has the potential to be utilized as an electrode material in supercapacitor applications, according to the results obtained.