Positive Electrode Material, Positive Electrode, and Lithium Secondary Battery Which Include Spinel-Structured Lithium Manganese-Based Positive Electrode Active Material

The present disclosure relates to a positive electrode material including a spinel-structured lithium manganese-based first positive electrode active material and a lithium nickel-manganese-cobalt-based second positive electrode active material, wherein the first positive electrode active material includes a lithium manganese oxide represented by Formula 1 and a coating layer which is disposed on a surface of the lithium manganese oxide, the second positive electrode active material is represented by Formula 2, and an average particle diameter of the second positive electrode active material is greater than an average particle diameter of the first positive electrode active material, and a positive electrode and a lithium secondary battery which include the positive electrode material: LiMnMOA [Formula 1] Li[NiCoMnM]OB [Formula 2]