▎ 摘　　要

NOVELTY - A cathode active material (10) comprises a core-shell structure comprising a core portion (11) comprising a sulfur compound, and a shell portion (13) comprising a polythiophene-acetic acid-polyethylene glycol graft copolymer, for coating at least a portion of surface or entire surface of the core portion. USE - Active material is used for forming cathode of lithium-sulfur battery (all claimed). Uses include but are not limited to power tool, portable electronic device, communication device, electric vehicle, hybrid electric vehicle, plug-in hybrid electric vehicle, electric bicycle, electric scooter and electric golf cart. ADVANTAGE - The cathode formed using the active material has excellent electrochemical reactivity, and provides lithium-sulfur battery having excellent cycle characteristics. The cathode active material has improved electroconductivity and ionic conductivity, and adsorbs lithium polysulfide to improve capacity and lifespan characteristics of the battery. By suppressing the elution of lithium polysulfide and maximizing the capacity expression of the cathode, the battery has high energy density. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) manufacture of the cathode active material, which involves preparing core portion containing sulfur compound, mixing the core portion with a solution containing polythiophene-acetic acid and a polyethylene glycol-based polymer, and heat-treating to form shell portion; and (2) cathode, which comprises the cathode active material. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the cathode active material. Cathode active material (10) Core portion (11) Shell portion (13)