Solid electrolyte coated silicon-based negative electrode material and preparation method thereof

The invention relates to a preparation method of a solid electrolyte coated silicon-based negative electrode material. The preparation method comprises the following steps of (1) preparing an ammoniumformate buffer solution, and uniformly dispersing a silicon negative electrode material in the buffer solution, adding an oxide precursor, stirring, until the surface of a silicon substrate is uniformly coated with oxide, and then performing centrifuging and drying to obtain an oxide-coated silicon composite material; and (2) carrying out mixing on the oxide-coated silicon composite material obtained in the step (1) and lithium hydroxide monohydrate, and then grinding uniformly to obtain mixed powder, carrying out high-temperature reaction on the mixed powder under the protection of inert gas, and cooling to the room temperature after the reaction is ended. According to the solid electrolyte coated silicon-based negative electrode material, the solid electrolyte is uniformly coated on thesurface of the silicon, a