POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERIES, POSITIVE ELECTRODE FOR LITHIUM SECONDARY BATTERIES, AND LITHIUM SECONDARY BATTERY

The object of the present invention is to provide a positive electrode active material usable for a lithium ion battery capable of high charge/discharge cycle performance and high discharge capacity. The positive electrode active material for a lithium secondary battery has a layered structure and comprises at least nickel, cobalt and manganese. Further, the positive electrode active material satisfies requirements (1) to (3) below: (1) a primary particle size of 0.1 µm to 1µm, and a 50 % cumulative particle size D 50 of 1 µm to 10 µm, (2) a ratio (D 90 /D 10 ) of volume-based 90% cumulative particle size D 90 to volume-based 10% cumulative particle size D 10 of 2 to 6, and (3) a lithium carbonate content in a residual alkali on particle surfaces of 0.1 % by mass to 0.8 % by mass as measured by neutralization titration.