POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM-ION BATTERY, A POSITIVE ELECTRODE FOR LITHIUM-ION BATTERY, AND LITHIUM-ION BATTERY

The present invention provides a positive electrode active material for lithium ion batteries having excellent battery property. The positive electrode active material for lithium ion batteries is represented by composition formula: Li x Ni 1-y M y O 2+a , wherein M is Co as an essential component and at least one species selected from a group consisting of Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Ga, Ge, Al, Bi, Sn, Mg, Ca, B and Zr, 0.9‰¦x‰¦1.2, 00.05, and an average particle size (D50) is 5µm to 15µm.