Positive-electrode active material for lithium-ion secondary battery, positive electrode and lithium-ion secondary battery

Abstract

An object of the present invention is to provide a novel sulfur-based positive electrode active material for a lithium-ion secondary battery which is excellent in cyclability and can largely improve a charging and discharging capacity, a positive electrode comprising the positive electrode active material and a lithium-ion secondary battery made using the positive electrode. The sulfur-based positive electrode active material is obtainable by subjecting a starting material comprising a polymer, sulfur and an organometallic compound dispersed in a form of fine particles to heat-treatment under a non-oxidizing atmosphere, wherein the particles of metallic sulfide resulting from sulfurization of the organometallic compound are dispersed in the heat-treated material, and particle size of the metallic sulfide particles is not less than 10 nm and less than 100 nm.

Dependencies are inferred from the claim text.