SPINEL TYPE LITHIUM MANGANESE OXIDE, ITS PRODUCTION AND USE

PROBLEM TO BE SOLVED: To obtain lithium manganese oxide having high performance as a positive electrode material of a lithium secondary cell by bringing a crystal structure to the spinel structure and specifying a molar ratio of lithium and manganese and average degree of oxidation of manganese. SOLUTION: This spinel type lithium manganese oxide is particles which have chemical composition and crystal structure containing lithium manganese spinel, LiMn2 O4 and/or an intermediate material, etc., between LiMn2 O4 and Li4 Mn5 O12 and having a molar ratio of lithium and manganese as Li:Mn=(0.9-1.10):2.00 and 3.40-3.60 average degree of oxidation of manganese and physical properties of the particles being 1-10m /g BET specific surface area, 0.01-1μm particle size of all primary particles and 1-30μm average particle size of coagulated particles made of the coagulated primary particles. The production process of the particles comprises mixing one or more manganese compounds selected from manganese oxide, hydrated manganese oxide, etc., with one or more lithium salts selected from lithium hydroxide, lithium nitrate, etc., and heat treating the resultant mixture at 500-850 deg.C.