LITHIUM MANGANESE-CONTAINING OXIDE AND METHOD OF PRODUCING SAME, CATHODE ACTIVE MATERIAL OF LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a lithium manganese-containing oxide which is available to improve a charge-discharge behavior at initial and after repeated charge-discharge actions with usage at high potential of greater than 4.5 V when a lithium ion secondary battery is used as a cathode active material.SOLUTION: A lithium manganese-containing oxide of this invention is represented by following Formula (I) as an average composition formula and contains a lithium manganate with a crystal structure of LiMnO. The lithium manganese-containing oxide satisfies 0.6 to 1.4 of I1/I2 which is a ratio of a peak intensity I1 around 2&thetas;=18° and a peak intensity I2 around 2&thetas;=45°, or 0.8 to 1.8 of I3/I4 which is a ratio of a peak intensity I3 around 2&thetas;=64° and a peak intensity I4 around 2&thetas;=66° in an XRD pattern. LiMnO(wherein 1.3≤x/y≤1.8) (I).