Preparation of mesoporous CoNiO2 hexagonal nanoparticles for asymmetric supercapacitors via a hydrothermal microwave carbon bath process

Abstract

Mesoporous CoNiO₂ (CNO) hexagonal nanoparticles are prepared via a hydrothermal microwave carbon bath process. The nanostructure and morphology of CNO NPs prepared at different hydrothermal temperatures are systematically studied and characterized. At the hydrothermal temperature of 140 °C, CNO hexagonal nanoparticles have a porous structure and a specific surface area of 53.56 m² g⁻¹. In addition, the as-prepared CNO electrode material exhibits a large capacitance of 801.00 F g⁻¹ at a current density of 0.5 A g⁻¹. The assembled CNO asymmetric supercapacitor shows a high energy density of 10.34 W h kg⁻¹ at the power density of 300 W kg⁻¹, which shows great potential as a novel electrode material in energy storage applications.