SILICON-BASED COMPOSITE MATERIAL, NEGATIVE ELECTRODE, LITHIUM ION BATTERY AND PREPARATION METHOD

The present disclosure relates to a porous nano-silicon-based composite material, an anode and a lithium ion battery and a preparation method thereof. The silicon-based composite material comprises nano active particles and graphite, and the nano active particles comprise porous nano-silicon; The graphite has a pore structure in which the nano active particles are embedded, and/or the graphite has a layered structure in which the nano active particles are embedded; Compared with the traditional carbon-coated silicon anode material, the silicon-based anode material prepared by the present disclosure has the advantage of lower expansion rate and thus improves cycle performance.