Cathode active material, cathode and lithium battery including cathode active material, and method of preparing the cathode active material

A method of preparing a lithium metal oxide composite comprising a first domain and a second domain, the method comprising:

• contacting a first lithium precursor, a transition metal precursor, and a metal dopant precursor to prepare a first mixture;
• firstly heat treating the first mixture to prepare a first domain lithium metal oxide;
• contacting the first domain lithium metal oxide with a second lithium precursor and a metal precursor to prepare a second mixture;
• and
• secondly heat treating the second mixture to prepare a second domain lithium metal oxide to prepare the lithium metal oxide composite,
• wherein the lithium metal oxide composite is represented by Formula 1:
• x[Li2-y(M1)1-z(M2)y+zO3]-(1−x)[LiMeO2] Formula 1
• wherein
• 0<x<1,
• 0≦y<1,
• 0≦z<1,
• 0<y+z<1,
• M1 comprises at least one transition metal,
• M2 comprises at least one metal selected from magnesium (Mg), aluminum (Al), vanadium (V), zinc (Zn), molybdenum (Mo), niobium (Nb), lanthanum (La), and ruthenium (Ru), and
• Me comprises at least one metal selected from nickel (Ni), Cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), titanium (Ti), copper (Cu), aluminum (Al), magnesium (Mg), zirconium (Zr), and boron (B).