POSITIVE ELECTRODE ACTIVE MATERIAL FOR SECONDARY BATTERY, METHOD FOR PREPARING SAME, AND LITHIUM SECONDARY BATTERY COMPRISING SAME

The present invention relates to a positive electrode active material for a secondary battery which includes lithium composite transition metal oxide particles including 70 mol% or more of nickel (Ni) among total metals excluding lithium, and a coating portion formed on surfaces of the lithium composite transition metal oxide particles, wherein the coating portion includes a compound including fluorine and at least one selected from the group consisting of aluminum (Al), titanium (Ti), magnesium (Mg), zirconium (Zr), tungsten (W), and strontium (Sr), a Brunauer-Emmett-Teller (BET) specific surface area is in a range of 0.1 m2/g to 0.9 m2/g, and an amount of a lithium by-product remaining on a surface of the positive electrode active material is 0.65 wt% or less based on a total weight of the positive electrode active material.