RECYCLED CATHODE ACTIVE MATERIAL, METHOD FOR RECYCLING CATHODE ACTIVE MATERIAL, AND SECONDARY BATTERY COMPRISING SAME

The present invention relates to a recycled positive electrode active material, a method of recycling a positive electrode active material, and a secondary battery including the recycled positive electrode active material. More particularly, the present invention relates to a recycled positive electrode active material including one or more selected from the group consisting of a lithium nickel oxide (LNO)-based positive electrode active material, a nickel·cobalt·manganese (NCM)-based positive electrode active material, a nickel·cobalt·aluminum (NCA)-based positive electrode active material, and a nickel·cobalt·manganese·aluminum (NCMA)-based positive electrode active material, including 60 mol% or more of Ni, containing fluorine (F) in an amount of 250 mg/kg or less, and having a crystallite size of 122 nm or less, a method of recycling a positive electrode active material, and a secondary battery including the recycled positive electrode active material. According to the present invention, the present invention has an effect of providing a positive electrode active material prepared by introducing oxygen into a waste positive electrode containing a high-nickel (Ni) positive electrode material, performing oxidation heat treatment, performing first washing, adding a lithium precursor, performing annealing, and performing second washing to reduce the amount of fluorine (F) on the surface of a recycled positive electrode active material, wherein the oxidation heat treatment is performed in two steps to completely burn a binder, reduce fluorine (F) and residual lithium generated in the heat treatment step, and reduce a crystallite size; and having excellent capacity, resistance characteristics, and capacity characteristics. In addition, the present invention has an effect of providing a method of recycling a positive electrode active material, characterized in that eco-friendliness is secured by not using acids in recovery and recycling processes; process cost is reduced because neutralization and wastewater treatment are not required accordingly; no metal element is discarded by recycling a positive electrode active material in an intact state without disassembling the positive electrode active material; the risk of toxic gas generation or explosion is excluded by not using an organic solvent; and economic feasibility and productivity are greatly improved by omitting a washing process.