▎ 摘　　要

NOVELTY - Negative electrode composition comprises a silicon-based active material, a negative electrode conductive material, and a negative electrode binder. The silicon-based active material includes at least one selected from silicon oxides (I) and (II). The silicon-based active material includes graphene; and the graphene has a structure surrounding the surface of the silicon-based active material. USE - The negative electrode composition is used in a negative electrode for a lithium secondary battery (claimed), which is used as a power source for medium and large-sized devices selected from plug-in hybrid electric vehicles and power storage systems. ADVANTAGE - The negative electrode composition uses a silicon-based active material, which is a high-capacity material, to manufacture a high-capacity battery, by adjusting the characteristics of the silicon-based active material itself, rather than adjusting the characteristics of the conductive material and the binder according to the volume expansion of the silicon-based active material. The composition has a high content of pure silicon-based active material to obtain a high-capacity and high-density negative electrode, and solves problems such as volume expansion due to having a high content of pure silicon-based active material by wrapping and using graphene on the silicon-based active material itself. The composition minimizes volume expansion during charging and discharging by using the treated silicon-based active material. DETAILED DESCRIPTION - Negative electrode composition comprises a silicon-based active material, a negative electrode conductive material, and a negative electrode binder. The silicon-based active material includes at least one selected from silicon oxide of formula: (SiOx) (I) and silicon oxide of formula: SiOx1(II). The composition contains 90 pts. wt. or more silicon oxide (I) based on 100 pts. wt. of the silicon-based active material. The silicon-based active material includes graphene. The graphene has a structure surrounding the surface of the silicon-based active material. x=0;and x1=0-2. INDEPENDENT CLAIMS are included for the following: a method for producing the negative electrode composition, comprising performing surface treatment of the silicon-based active material, heat-treating graphite to form graphene oxide, forming graphene covering the surface of the silicon-based active material by mixing and heat-treating the surface-treated silicon-based active material and the graphene oxide, and mixing the silicon-based active material, the negative electrode conductive material, and the negative electrode binder; a negative electrode for a lithium secondary battery comprising a negative electrode current collector layer, and an negative electrode active material layer comprising the negative electrode composition formed on one side or both sides of the negative electrode current collector layer; and a lithium secondary battery comprising a positive electrode, the negative electrode, a separator provided between the positive electrode and the negative electrode, and electrolytes.