Positive electrode active material for lithium secondary battery, method for preparing same, and lithium secondary battery comprising same

The present invention relates to a positive electrode active material, a method for preparing the same, and a lithium secondary battery comprising the same, the positive electrode active material comprising at least one secondary particle comprising an aggregate of primary large particles. According to an embodiment of the present invention, there may be provided a positive electrode active material comprising secondary particles having improved electrical resistance by simultaneously increasing an average particle diameter D50 and a crystal size of primary large particles. According to an embodiment of the present invention, a positive electrode active material having a high crystal density can be provided. Accordingly, a nickel-based positive electrode active material having improved lifespan and resistance characteristics can be obtained by securing a movement path of lithium ions and minimizing defects in a crystal structure of the positive electrode active material. 本发明涉及正极活性材料、其制备方法和包含其的锂二次电池，所述正极活性材料包含