Positive Electrode Active Material Precursor for Secondary Battery, Preparation Method Thereof and Method of Preparing Positive Electrode Active Material

A positive electrode active material precursor for a secondary battery,

• wherein the positive electrode active material precursor is prepared by a co-precipitation reaction while adding a transition metal-containing solution containing transition metal cations, a basic solution, and an ammonium solution to a batch-type reactor,
• wherein a molar ratio of ammonium ions contained in the ammonium solution to the transition metal cations contained in the transition metal-containing solution added to the batch-type reactor is 0.5 or less, and the pH in the batch-type reactor is maintained at 11.2 or less,
• wherein the positive electrode active material precursor has an aspect ratio of a primary particle of less than 0.5, the positive electrode active material precursor has an average particle diameter (D50) of a secondary particle ranging from 4 μm to 20 μm, and the positive electrode active material precursor has a specific surface area of 9 m2/g or more.