POSITIVE ELECTRODE ACTIVE MATERIAL, POSITIVE ELECTRODE, BATTERY, AND PRODUCTION METHOD FOR LITHIUM ION SECONDARY BATTERY

摘要

The present invention provides a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charged at a high voltage, a cathode, a lithium ion secondary battery and a method for producing a cathode active material for a lithium ion secondary battery. The cathode active material comprises particles (II) having an oxide (I) of at least one metal element selected from Zr, Ti and Al locally distributed at the surface of a lithium-containing composite oxide comprising Li element and at least one transition metal element selected from the group consisting of Ni, Co and Mn (provided that the molar amount of the Li element is more than 1.2 times the total molar amount of said transition metal element).