| abstract |
The present invention relates to a sulfur-carbon composite comprising a carbon-based material surface-modified by acid treatment, a preparation method therefor, and a lithium-sulfur battery comprising the same. According to the present invention, the sulfur-carbon composite comprises a carbon-based material surface-modified so as to have, on the surface thereof, a hydroxyl group and a carboxyl group capable of adsorbing polysulfide, and thus the elution of polysulfide is prevented when the sulfur-carbon composite is used as a cathode active material of a lithium-sulfur battery. Therefore, the capacity characteristics and the lifespan characteristics of a battery can be improved. In addition, according to the sulfur-carbon composite preparation method of the present invention, the surface of a carbon-based material can be modified by a simple process of treating with a mixed solution of nitric acid and sulfuric acid, and the amount of functional groups on the surface can be controlled according to the mixing ratio of nitric acid and sulfuric acid. |