Precursor for Positive Electrode Active Material, Positive Electrode Active Material, Method of Manufacturing Precursor for Positive Electrode Active Material, Positive Electrode, and Lithium Secondary Battery

A positive electrode active material comprising:

• a lithium nickel-based oxide containing nickel in an amount of about 60 mol % or more based on total metal content excluding lithium,
• wherein a ratio of an average crystallite size (unit:
• nm) to a Ni content (unit:
• mol %) is about 1.9 nm/mol % to 3.0 nm/mol %, based on the total metal content excluding lithium.

A method of preparing a positive electrode active material, the method comprising:

• mixing a precursor for a positive electrode active material including a nickel-based hydroxide containing nickel in an amount of about 60 mol % or more based on total metal content with a lithium raw material, and calcining the mixture to prepare a positive electrode active material,
• wherein the precursor for a positive electrode active material has a ratio of a (101) crystallite size (unit:
• nm) to a Ni content (unit:
• mol %) of about 1.5 nm/mol % to 2.0 nm/mol %, based on the total metal content.