Lithium managanese oxide, cathode material for lithium secondary battery, cathode, lithium secondary battery and process for manufacturing lithium manganese oxide

摘要

The invention provides a lithium manganese oxide spinel suited as a cathode active material for lithium ion secondary batteries showing excellent high-temperature cycling behavior. The lithium manganese oxide is represented by the following general formula (1): Li1+alphaMn2-alpha-yMyO4-deltawherein O<=alpha<=0.5, 0.005<=y<=0.5, -0.1<=delta÷0.1, and M represents a metal element other than Li and Mn, and which shows the ratio of a main peak intensity at 5±40 ppm to a main peak intensity at 525+40 ppm (I0ppm/I500ppm), each intensity being obtained by 7Li-NMR measurement according to the following measuring method, falling within the following range: I0ppm/I500ppm<=0.65y+0.02