▎ 摘　　要

NOVELTY - Silicon-carbon composites comprises core-shell structure comprising a core comprising a silicon-containing constituent having a crystallite size of a silicon crystal of 2-50 nm and a first carbon; and a shell comprising a second carbon, located on the surface of the core, where the second carbon includes grapheme or reduced graphene oxide. USE - The silicon-carbon composite is useful in anode active material for secondary battery (all claimed), preferably lithium secondary battery. ADVANTAGE - The silicon-carbon composite improves the capacity retention by increasing initial charging/discharging efficiency and improving charging/discharging capacity; has a large irreversible capacity and short lifespan; can prevent or reduce the occurrence of side reactions with the electrolyte solution, so that the discharge capacity, life characteristics, and thermal stability can be improved; has excellent electrical conductivity, thus improving the performance of the lithium secondary battery; occurrence of cracks due to the rapid volume expansion of the silicon-containing constituent of the core can be suppressed by the shell containing the second carbon uniformly formed; can directly grow a graphene-containing material that is flexible in volume expansion due to excellent conductivity on the surface of the powder on which the core containing silicon particles is formed, thus suppressing volume expansion. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) producing silicon-carbon composite comprising (i) adding and mixing pure water to silicon-containing material, then press-molding with a pellet machine, heat-drying and injecting into a crucible, (ii) forming a core including silicon and carbon by introducing a first carbon precursor into the crucible and performing chemical pyrolysis method, (iii) replacing the inside of the crucible with an inert gas, cooling the material produced in the step (ii), and pulverizing to produce a powder having a core, (iv) forming a shell including a second carbon layer on the surface of the core by injecting a second carbon precursor into the core-formed powder, performing chemical pyrolytic deposition method and cooling, and (v) cooling, crushing, and classifying the material prepared in the step (iv); (2) anode active material for secondary battery, comprising silicon-carbon composite as an anode active material; and (3) secondary battery comprising an anode molded body comprising anode active material, cathode molded body, an electrolyte to allow ions to move between the anode molded body and the cathode molded body, and a separator arranged between the anode molded body and cathode molded body in the electrolyte.