Preparation method and application of self-assembled tricobalt tetroxide graded microspheres

The invention discloses a preparation method and application of self-assembled tricobalt tetroxide graded microspheres. The preparation method comprises the following steps of: dispersing cobalt saltand polyvinyl alcohol in a mixed solution of ethylene glycol and deionized water, obtaining a cobalt hydroxide precursor by a hydrothermal method, subjecting the cobalt hydroxide precursor to high temperature annealing treatment, and finally obtaining tricobalt tetroxide microspheres of a hierarchical structure formed by self-assembly of two-dimensional nanosheets. The obtained tricobalt tetroxidegraded microspheres are specifically applied to supercapacitor electrode materials, and the specific capacitance retention rate is over 70%. The method utilizes the pyrolysis gasification property ofpolyvinyl alcohol to generate a large number of hollow micropores in the structure of tricobalt tetroxide, increases the porosity and specific surface area thereof, and increases active sites, and the prepared tricobalt tetrox