A method for making an anode active material is described. The anode active material includes a phosphorus composite material. In the method, a solid-state red phosphorus and a porous conductive carbon material are provided. The solid-state red phosphorus and the porous conductive carbon material are spaced disposed in a vessel and the vessel is sealed. The solid-state red phosphorus is sublimed by heating the vessel to make the sublimed red phosphorus diffused in the porous conductive carbon material. The sublimed red phosphorus is condensed. The condensed red phosphorus adsorbs in the porous conductive carbon material to form the phosphorus composite material.