Lithium manganese composite oxide, positive electrode material for lithium secondary battery, positive electrode, lithium secondary battery, and method for producing lithium manganese composite oxide

摘要

PROBLEM TO BE SOLVED: To provide a lithium manganese multiple oxide suitable as a positive electrode active material for lithium ion secondary cell having excellent high temperature cycle characteristic property. SOLUTION: The lithium manganese multiple oxide is expressed by general formula Li1+Mn2--yO4-, wherein, 0==0.5, 0.005=y=0.5, -0.1==0.1 and M expresses an element other than lithium and manganese, and the ratio (I0 ppm/I500 ppm) of the main peak intensity obtained by 7Li-NMR measurement in 540 ppm to that in 52540 ppm is in the range of I0 ppm/I500 ppm=0.65y+0.02.