Silicon-carbon composite for secondary battery negative electrode material, and method for preparing same

A method for preparing a silicon-carbon composite, the method comprising:

• (S1) raising a temperature of a rotary furnace to a temperature of 400° C. to 650° C. while the rotary furnace has been purged with inert gas;
• and
• (S2) simultaneously introducing a silicon source gas and a carbon source gas into the rotary furnace to perform a homogenous reaction under an atmospheric pressure condition such that silicon and carbon are co-deposited to obtain the silicon-carbon composite,
• wherein the obtained silicon-carbon composite includes silicon particles and a carbon material,
• wherein an average crystallite size of the silicon particles is 10 nm or smaller,
• wherein a D50 value of the silicon-carbon composite is in a range of 1 μm to 10 μm,
• wherein a sphericity of the silicon-carbon composite is 0.7 or greater.