Method for preparing anode active material

摘要

Disclosed is a method including (a) mixing a precursor of a material for preparing at least one material selected from the group consisting of low crystalline carbon and amorphous carbon with a hydrophilic material, followed by purification to prepare a mixture for coating, (b) mixing the mixture for coating with a crystalline carbon-based material to prepare a core-shell precursor in which the mixture for coating is coated on a core including a crystalline carbon-based material, and (c) calcining the core-shell precursor to carbonize the material for preparing the at least one material selected from the group consisting of low crystalline carbon and amorphous carbon into the at least one material selected from the group consisting of low crystalline carbon and amorphous carbon.

主权项

1. A method for preparing an anode active material comprising a core comprising a crystalline carbon-based material and a composite coating layer comprising at least one material selected from the group consisting of low crystalline carbon and amorphous carbon and an aluminum oxide, a magnesium oxide, a zirconium oxide, or mixtures thereof, the method comprising:
(a) mixing a precursor of a material for preparing the at least one material selected from the group consisting of low crystalline carbon and amorphous carbon with the hydrophilic material, followed by purification to prepare a mixture for coating, wherein the precursor for the raw material of the one or more materials selected from the group consisting of low crystalline carbon and amorphous carbon is a pitch solution and the pitch solution is mixed with an aluminum oxide, a magnesium oxide, a zirconium oxide, or mixtures thereof, prior to purification of the pitch solution; (b) homogenously mixing the mixture for coating with the crystalline carbon-based material to prepare a core-shell precursor in which the mixture for coating is coated on the core comprising the crystalline carbon-based material; and (c) calcining the core-shell precursor to carbonize the material for preparing the at least one material selected from the group consisting of low crystalline carbon and amorphous carbon into amorphous carbon, wherein after mixing of the pitch solution with the aluminum oxide, the magnesium oxide, the zirconium oxide, or mixtures thereof, the mixture is subjected to purification, wherein purification comprises removing impurities by thermal treatment, followed by cooling and grinding, wherein the impurities comprise hydrocarbons and sulfur having a relatively low boiling point, and wherein said thermal treatment is conducted under an inert atmosphere at a temperature of 350° C. to 700° C.