▎ 摘　　要

NOVELTY - A sulfur-carbon composite comprises carbon substrate and sulfur, where carbon substrate consists of microporous carbon layers and graphene sheets in which microporous carbon layers are interbedded into the interlayer of the graphene sheets, and sulfur is encapsulated into the microporous structure of the carbon substrate. USE - A sulfur-carbon composite for electrode used in a lithium-sulfur battery (all claimed). Can be used in power tools, photovoltaic cells, and electric vehicles. ADVANTAGE - By combining stacked graphene sheets that are interbedded by the microporous carbon layers, the carbon substrate containing graphene sheets and microporous carbon layers (G@MC) achieves large pore volume which can encapsulate high content of sulfur and polysulfides in the stacked microporous structure. The G@MC with numerous sp2 hybrid carbons ensures high conductivity and, can provide three-dimensional electron transfer pathways for sulfur and discharge products. In addition, the G@MC with the stacked structure can absorb numerous polysulfides and confine the diffusion of polysulfides, and provide adequate nanospace for sulfur expansion, ensuring the structural integrity during the cycling. As a result, higher sulfur loading, better capacity retention, and rate capability improvement can be achieved. The high-energy-density lithium ion batteries containing the sulfur-carbon composite has acceptable high power density for energy storage applications. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of sulfur-carbon composite which involves (1) preparing graphene oxides; (2) adding carbonaceous precursor into aqueous solution of graphene oxides, together with sulfuric acid and refluxing, then filtering and drying; (3) infiltrating the material into a solution containing chemical activating agent, followed by heating at 70-900 degrees C in an inert atmosphere; (3') or alternatively, directly heating material by gas etching method at 700-900 degrees C; (3'') or alternatively, infiltrating the material into a solution containing chemical activating agent, followed by heating at 700-900 degrees C in an etching gas atmosphere, where either steps (3), or step (3'), or step (3'') is performed; (4) neutralizing and purifying material from step (3), or step (3'), or step (3'') is neutralized and purified to obtain the carbon substrate; and (5) loading sulfur into the carbon substrate. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of a carbon-sulfur cathode material based on the carbon substrate containing graphene sheets and microporous carbon layers and the carbon substrate containing graphene sheets and microporous carbon layers further loaded with sulfur.