| abstract |
The present invention relates to a positive electrode active material containing a lithium metal composite oxide having a layered crystal structure and capable of suppressing a reaction with an electrolytic solution to improve lifetime characteristics of the battery, Thereby providing a composite oxide powder. A surface portion in which one or more kinds of combinations of Al, Ti and Zr (referred to as " surface element A ") is present on the surface of particles of a lithium metal composite oxide having a layered crystal structure Wherein the amount of the surface LiOH is less than 0.10 wt% and the amount of surface Li 2 CO 3 is less than 0.25 wt%, and in the X-ray diffraction pattern, the amount of the lithium metal composite oxide 104) plane is more than 1.15, and the S amount obtained by ICP measurement is less than 0.10 wt% of the lithium metal composite oxide powder (100 wt%). Lithium metal complex oxide powder. |