Sulfur-carbon composite, preparation method thereof, positive electrode for lithium secondary battery and lithium secondary battery comprising same

A sulfur-carbon composite comprising:

• a porous carbon material, wherein the porous carbon material comprises carbon nanotubes, and wherein the porous carbon material is not graphitized;
• and
• sulfur, wherein the sulfur is present in at least a part of an inside of the porous carbon material and on a surface of the porous carbon material, wherein the sulfur-carbon composite has a specific surface area of 7 m2/g to 20 m2/g and a pore volume of 0.1 cm3/g to 0.3 cm3/g, and
• wherein the porous carbon material is a porous carbon material surface-modified with a hydrophilic functional group, where the functional groups have been removed by heat-treating the porous carbon material.