Facile hydrothermal synthesis and fabrication of nickel cobalt oxide as an advanced electrode for electrochemical capacitors

Abstract

The surface chemistry and decent morphology of electrode materials are highly desirable for high-performance energy storage/conversion devices. Bimetallic oxides especially nickel cobalt oxide (NCO) have gained substantial attention in energy storage/conversion devices owing to their exclusive electronic properties. Herein, flower-like nickel cobalt oxide (NiCo2O4) was prepared by a facile hydrothermal method for different reaction times. The properties of obtained samples were characterized through X-ray diffraction (XRD), EDS, field-emision scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). The cyclic voltammogram (CV), Galvanostatic changing discharging (GCD), and electrochemical impedance spectroscopy (EIS) were employed for the evaluation of the electrochemical performances of the resultant product. The flower-like NiCo2O4 electrode exhibits high areal capacity (392 mF cm−2 at 0.5 mA cm−2) and the electrode shows an energy density of about 9.1 µWh cm−2 at power density 102 µW cm−2. The excellent electrochemical performance of the fabricated supercapacitor offers good areal capacitance and energy density that exceeds several carbon-based materials.