▎ 摘　　要

NOVELTY - Thermally expanded reduced graphene oxide comprises pores in its surface, where the average size of the surface pores is 0.5-4 nm. USE - The thermally expanded reduced graphene oxide is useful in a sulfur-carbon complex and a lithium secondary battery, preferably lithium-sulfur battery (all claimed). ADVANTAGE - The thermally expanded reduced graphene oxide increases the amount of the positive electrode material containing sulfur, increases the life of the battery, maximizes the content of sulfur in the anode material, while minimizing the content of the conductive material, uniformly supports the conductive material, has high specific surface area and pore volume to increase the content of sulfur carried on graphene oxide, and improves the discharge capacity in a high-rate section by facilitating the transport of lithium ions and electrons of a battery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for manufacturing the thermally expanded reduced graphene oxide, involving (a) thermally expanding graphene oxide by heat treatment, (b) reducing the heat-expanded graphene oxide by heat treatment, and (c) vapor activating the thermally expanded reduced graphene oxide to form pores on the surface; (2) a sulfur-carbon complex comprising the thermally expanded reduced graphene oxide, and sulfur on at least a portion of the surface pores, internal pores and surfaces of the thermally expanded reduced graphene oxide; and (3) a lithium secondary battery comprising positive electrode, negative electrode, separator interposed between the positive electrode and the negative electrode, and electrolyte, where the positive electrode comprises the sulfur-carbon complex.