Study on solvothermal synthesis of nickel cobaltite and its electrochemical properties

With cobalt nitrate and nickel nitrate as raw materials, ethanol and isopropanol of different concentrations as solvents, the precursor was synthesized on foam nickel by solvothermal method and calcined to obtain nickel cobaltite, to investigate the effects of solvent type and concentration on the morphology and electrochemical properties of the synthesized products. The sample was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) to determine the phase composition and to observe its micromorphology. The electrochemical properties of the sample were tested by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results show that the nickel cobaltite synthesized in 50% volume concentration of ethanol solution and isopropanol solution both have a regular nanowire structure, which is conducive to the redox reaction, contributing to the good electrochemical properties of the material. The nickel cobaltite synthesized in 50% volume concentration of ethanol solution shows better electrochemical performance, with a specific capacitance of 627 F/g at the current density of 1 A/g, and a capacity retention rate of 94% after 500 cycles at the current density of 10 A/g.