Positive active material for lithium secondary battery and lithium secondary battery comprising same

A positive active material for a lithium rechargeable battery, comprising:

• a nickel-based lithium metal oxide particle doped with Zr and Al;
• and
• a coating layer disposed on the surface of the nickel-based lithium metal oxide particle,
• wherein
• the nickel-based lithium metal oxide particle includes
• a core portion, and
• a shell portion surrounding the core portion and forming a concentration gradient in which a concentration of nickel gradually decreases from an interface with the core portion toward an outer direction,
• the coating layer includes an oxyhydroxide of a rare earth element, wherein the rare earth element is cerium (Ce),
• the nickel-based lithium metal oxide particle includes:
• a first particle having an average particle diameter of 10 μm to 30 μm, and
• a second particle having an average particle diameter of 1 μm to 6 μm,
• a molar ratio of Zr:Al in the nickel-based lithium metal oxide particles is 10:1 to 2:1.