A Novel Electrode Material of NiO Prepared by Facile Hydrothermal Method for Electrochemical Capacitor Application

NiO nanosheets were prepared by a facile and template-free hydrothermal process using l-arginine as the alternative precipitator and nickel sulfate as the nickel source. The as-synthesized materials were characterized by x-ray diffraction, Field emission scanning electron microscopy, N₂ adsorption-desorption, and the electrochemical workstation. The results show that the novel NiO material possesses a large surface area of 121 m²/g and binary pore structure of micropore and mesopore. The electrochemical tests show that the NiO electrode exhibits a specific capacitance as large as 300 F/g at the current density of 1 A/g and the specific capacitance retention can maintain 84% after 500 cycles at the current density of 15 A/g in 6 mol/L KOH.