Positive active material for rechargeable lithium batteries, preparation method thereof and rechargeable lithium batteries including the same

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

• a first positive active material comprising a plurality of secondary particles, each of the plurality of secondary particles comprising a plurality of aggregated primary particles, and
• a second positive active material comprising a plurality of single particles,
• wherein each of the first positive active material and the second positive active material independently comprises a lithium nickel-based composite oxide having a nickel content of greater than or equal to about 70 mol % relative to the total elements thereof, excluding lithium and excluding oxygen,
• the first positive active material comprises a coating portion in a form of a film on surfaces of the plurality of secondary particles,
• the second positive active material comprises a coating portion in a form of a film on surfaces of the plurality of single particles, and
• the coating portion of the first positive active material and the coating portion of the second positive active material comprises lithium cobalt oxide and cobalt oxyhydroxide, respectively.