Synthesis and electrochemical properties of OEB@NiO based electrode material

[Display omitted] •Synthesis and characterisation of OEB@NiO based electrode material.•Cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy.•Cyclic stability, and power and energy densities. The development of oil-extracted biochar and NiO-based hybrid electrode materials (OEB@NiO) for supercapacitor applications is the focus of the present work. The biochar was prepared using cow dung via thermochemical treatment. The sol–gel method was used to synthesise the NiO nanoparticles. The OEB@NiO-based nanocomposite was developed under ultrasonic conditions. The electrochemical investigation of OEB@NiO was carried out using GCD, CV, and EIS techniques. The maximum specific capacitance was determined to be 545.4 F/g at a current density of 8 A/g under a three-electrode system. The material proved suitable for device systems; the specific capacitance of 87.1 F/g was obtained at a current density of 2 A/g in a two-electrode system. The cyclic stability of OEB@NiO was found to be 97.2% after 5000 GCD cycles.