Hydrothermally synthesized microrods and microballs of NiCo₂O₄ for supercapacitor application

The microrods and microballs of NiCo₂O₄ are successfully synthesized by the hydrothermal method. The effect of ammonium hydroxide and ammonium fluoride on the surface microstructure is observed. The prepared microrods and microballs of NiCo₂O₄ are analyzed by various analytical tools like powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), with energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The electrochemical properties are studied by using cyclic voltammetry (CV), galvanostatic charge discharge (GCD), and electrochemical impedance spectroscopy (EIS), using the workstation Biologic SP-200. The maximum specific capacitance of the NiCo₂O₄ microrods electrode is 1671 F/g. The areal specific capacitance of the NiCo₂O₄ microrods electrode is 284 mF/g. The energy density and power density of microrods of NiCo₂O₄ electrode are 19 Wh/Kg and 282 W/kg, respectively. The equivalent series resistance (Rs) is 0.62 Ω for NiCo₂O₄ microrods.