Preparation method of graded pore structure metal oxide lithium ion battery negative electrode

The invention provides a preparation method of a graded pore structure metal oxide lithium ion battery negative electrode, which comprises the following steps of: uniformly mixing a mixed solution A of metal chloride and N, N-dimethylformamide and a mixed solution B of sodium hydroxide and selenium oxide in a reaction kettle, fully reacting in an air dry oven at a proper temperature, and drying to obtain the graded pore structure metal oxide lithium ion battery negative electrode. Cleaning and drying to obtain metal selenide nanoparticles; pressing the metal selenide nanoparticles into tablets by using a tablet press, putting the tablets into a tubular furnace for high-temperature sintering, reacting the metal selenide with oxygen to generate metal oxide and selenium oxide, sublimating selenium oxide at high temperature to leave nanoscale small holes in the original position, and sintering the metal selenide to form submicron-to-micron-scale large holes among the particles, so as to obtain the metal selenide