Anode material and preparation method thereof, composite anode material and lithium ion battery

The invention relates to the technical field of electrode materials, in particular to an anode material and a preparation method thereof, a composite anode material and a lithium ion battery. The anode material comprises a substrate, the substrate contains a silicon oxide, boron nitride and an optional carbon element, the general formula of the silicon oxide is SiOx, and x is greater than or equal to 0.5 and less than or equal to 1.7; wherein based on the total weight of the matrix, the sum of the content of the silicon oxide and the content of the boron nitride is 3-100 wt%. According to the anode material provided by the invention, through the covalent bond formed between the boron nitride and the silicon oxide, the boron nitride is kept stable in the charge-discharge process of the anode material, and the problems of expansion and pulverization of the anode material in the application process are effectively inhibited, so that the electrochemical performance of the lithium ion battery containing the anode