Patent ID: 9077001
Filing Date: 2015-07-07
Classification: H01M,Y02E,Y02P

Abstract:
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 silicon or Sn, or an alloy of silicon and Sn capable of intercalating and deintercalating ions, 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 metal and/or non-metal capable of intercalating and deintercalating ions, followed by purification to prepare a mixture for coating; (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 the at least one material selected from the group consisting of low crystalline carbon and amorphous carbon, wherein after mixing of the pitch solution with a silicon or Sn, or an alloy of silicon and Sn capable of intercalation and deintercalation of ions, 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.