METHOD FOR PRODUCING POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERY

One aspect provides a method for producing a positive electrode active material for a lithium ion secondary battery that can improve battery characteristics of a lithium ion secondary battery. [0002] One aspect of the present disclosure relates to a method for producing a positive electrode active material for a lithium ion secondary battery, the positive electrode active material consisting of a lithium metal composite oxide. The method includes the following steps (1) and (2): (1) mixing a dispersant (component A) being a copolymer containing a constitutional unit derived from (meth)acrylic acid and a constitutional unit derived from unsaturated dibasic acid or its anhydride, a salt (component B) of at least one metallic element selected from nickel, cobalt, manganese, and aluminium, an alkali (component C), and an aqueous medium to precipitate, as a coprecipitate, a metal hydroxide containing the at least one metallic element selected from nickel, cobalt, manganese, and aluminium; and (2) baking a mixture containing the metal hydroxide obtained in the step (1) and a lithium compound to obtain the lithium metal composite oxide.