LITHIUM MANGANESE OXIDE POSITIVE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY INCLUDING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a lithium manganese oxide positive active material which improves energy density per unit volume and power capability of a lithium ion secondary battery.SOLUTION: The lithium manganese oxide positive active material for a lithium ion secondary battery includes spinel lithium manganese oxide particles of three or more types having different sizes mixed therein. Of these particles, first type particles have an average diameter of 5 μm or greater, second type particles have an average diameter of 1 μm or less, third type particles have an average diameter of 200 nm or less, and the average diameter of the second type particles is greater than the average diameter of the third type particles.