METHOD FOR PRODUCING COMPLEX OXIDE, POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

摘要

A composite oxide, whose major component is a lithium-manganese-system oxide including Li and tetravalent Mn at least and having a crystal structure that belongs to a layered rock-salt structure, is produced via the following:
a raw-material mixture preparation step of preparing a raw-material mixture by mixing a metallic-compound raw material and a molten-salt raw material with each other,
the metallic-compound raw material at least including one or more kinds of metallic compounds being selected from the group consisting of oxides, hydroxides and metallic salts that include one or more kinds of metallic elements in which Mn is essential,
the molten-salt raw material including lithium hydroxide and lithium nitrate, and exhibiting a proportion of the lithium hydroxide with respect to the lithium nitrate (i.e., (Lithium Hydroxide)/(Lithium Nitrate)) that falls in a range of from 1 or more to 10 or less by molar ratio;
a molten reaction step of reacting said raw-material mixture at a melting point of said molten-salt raw material or more by melting it: and
a recovery step of recovering said composite oxide being generated from said raw-material mixture that has undergone the reaction.