Method for preparing porous carbon material, and sulfur-carbon composite and lithium-sulfur battery including the same

A method for preparing a sulfur-carbon composite, comprising:

• preparing a porous carbon material having a D50 particle size of 20 μm to 100 μm, comprising:
• (1) a step of centrifugally milling a porous carbon material with a centrifugal mill;
• and
• (2) a step of filtering the centrifugally milled porous carbon material through a sieve,
• wherein the steps (1) and (2) are performed at the same time,
• wherein a mesh size of the sieve is 2.8 to 4 times of the D50 particle size of the porous carbon material filtered through the sieve in the step (2),
• wherein the porous carbon material filtered through the sieve in the step (2) has a broadness factor (BF) of 7 or lower, and
• wherein the broadness factor (BF) satisfies Equation 1:
• Broadness factor (BF)=(particle size D90 of the porous carbon material after the step (2))/particle size D10 of the porous carbon material after the step (2)), and [Equation 1]
• loading a sulfur-based material onto all or at least some of inner pores and outer surfaces of the porous carbon material,
• wherein the porous carbon material comprises carbon nanotubes.