| 摘要 |
The present invention relates to a method for preparing an anode active material, comprising (S1) forming a shell being a coating layer comprising a carbon material on the surface of a core comprising silicon oxide particles, to obtain a silicon oxide-carbon composite having a core-shell structure; (S2) mixing the silicon oxide-carbon composite with an oxygen-containing lithium salt, followed by heat treatment to produce a silicon oxide-lithium alloy, thereby obtaining a (SiO x -Li y )-C (0<x<1.5, 0<y<4) composite having a core-shell structure; and (S3) washing the surface of the (SiO x -Li y )-C composite having a core-shell structure and drying the composite, and an anode active material prepared by the method. In accordance with the method of present invention, which prepares an anode active material of a (SiO x -Li y )-C composite having a core-shell structure, a silicon oxide-core has a carbon material-coating layer on the surface thereof to prevent oxygen present in an oxygen-containing lithium salt from infiltrating into silicon oxides, thereby easily controlling the amount of oxygen present in the silicon oxides. Also, the anode active material of the present invention can be prevented from the gelation of an anode active material slurry by removing the remaining lithium sources and by-products of the reaction between lithium sources and silicon oxides. In addition, an anode active material of a (SiO x -Li y )-C composite having a core-shell structure, prepared by such method provides high capacity, good life characteristics and superior thickness expansion control to batteries. |
