Preparation method of fluorinated niobium titanium oxygen hollow sphere and application thereof in lithium ion battery

Abstract

The application relates to a preparation method of fluorinated niobium-titanium oxygen hollow spheres and application of the fluorinated niobium-titanium oxygen hollow spheres in lithium ion batteries. The method comprises the following steps: preparing silica microspheres, preparing niobium-titanium oxygen hollow spheres by taking the prepared silica microspheres as templates. A niobium-titanium oxygen material (SiO2@TiNb2O7) loaded on microspherical titanium dioxide is prepared by a solvothermal method. Then, the SiO2@TiNb2O7 is dissolved in a hydrofluoric acid (30 wt%) solution, and is transferred into a reaction kettle to obtain fluorinated niobium-titanium oxygen hollow sphere materials. The preparation method realizes the fluorination of niobium-titanium oxygen and the preparation of hollow spheres by a one-step method. The hollow sphere structure improves the specific surface area, can bear a larger real current density, is favorable for the fast deintercalation of lithium ions, the fluorination improves the electronic conductivity of the niobium-titanium oxygen material, greatly improves the rate performance, and the fluorination can passivate the electrode surface, inhibit the occurrence of interface side reactions, and further inhibit the gas production behavior. The preparation method can be used in the field of high-power niobium-titanium oxygen-based lithium ion batteries.