CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, MANUFACTURING METHOD THEREOF, PRECURSOR OF CATHODE ACTIVE MATERIAL, MANUFACTURING METHOD THEREOF, AND LITHIUM SECONDARY BATTERY USING CATHODE ACTIVE MATERIAL

PROBLEM TO BE SOLVED: To provide a lithium secondary battery attaining both high safety and high capacity and excellent in cycle life, using a cathode active material for lithium secondary batteries which is fine, capable of attaining high capacity and high in performance, moreover, to provide a precursor and a manufacturing method thereof used for obtaining the cathode active material for lithium secondary batteries, and in addition, to provide the manufacturing method suitable for industrial production.SOLUTION: A cathode active material for lithium secondary batteries consists of a metal lithium silicate salt represented by a general formula LiMSiO, where 1.90≤x≤2.15, 0.90≤y≤1.10, and M denotes one or more elements selected from Mn, Fe, Ni and Co, and is constituted of metal lithium silicate salt particles consisting of primary particles and secondary particles formed by aggregation of the primary particles. A primary particle diameter is 10-300 nm. A secondary particle diameter is 0.5-10 μm. A specific surface area of the cathode active material is 25-35 m/g, and its carbon content is 3-7 mass%.