NOVELTY - A positive electrode active material comprises lithium intercalating mixed metal oxide composition.    USE - As positive electrode active material in a lithium ion secondary battery (claimed) for high energy applications, such as electric vehicles and plug in hybrid vehicles, mobile communication devices (such as phones and mobile entertainment devices e.g. MP3 players and televisions, and portable computers).    ADVANTAGE - The positive electrode active material has a 10th cycle discharge capacity of 240 mAh/g or 250-270 mAh/g at room temperature at a discharge rate of C/3 when discharged from 4.6-2 volts; has a tap density of at least 1.8 g/ml; and has a first cycle irreversible capacity loss of not greater than 70 mAh/g at a discharge rate of C/10. The positive electrode active material for a lithium ion battery has an average discharge voltage of 3.63 volts at a discharge rate of C/10, a 40th cycle discharge capacity at least 90% of the 10th cycle discharge capacity when cycled between the 10th cycle and the 40th cycle at room temperature at a discharge rate of C/3 and from 4.6-2 volts, and a 46th cycle discharge capacity of 170 mAh/g at room temperature at a discharge rate of 2C and from 4.6-2 volts. The lithium ion secondary battery using the positive electrode active material shows at least 95% capacity at 40 cycles relative to cycle 10 at a C/3 discharges from 4.6-2 volts for the tenth cycle through the 40th cycle. The lithium ion battery using the positive electrode materials shows combination of excellent cycling performance, high specific capacity, high overall capacity, high average voltage, improved rate, and low impedance.    DETAILED DESCRIPTION - A positive electrode active material comprises lithium intercalating mixed metal oxide composition of formula Li1+xNiaMnb-dCocAd-XmO2-zFz (I).    x=0.01-0.3;    a=0.1-0.4;    b=0.25-0.65;    c=0-0.4;    d=0.001-0.15;    m=0-0.1;or    x+a+b+c+d+m= approximately 1;    z=0-0.2;    A=Mg, Ca, Sr, Ba, Zn and/or Cd;    X=transition metal distinct from A, Ni, Mn or Co.    INDEPENDENT CLAIMS are included for the following:    (1) a positive electrode comprising the positive electrode active material, an electrically conductive material that is distinct from the positive electrode active material, and a binder;    (2) a lithium ion secondary battery comprising a positive electrode comprising the positive electrode active material, a negative electrode containing elemental carbon and a separator between the positive electrode and the negative electrode;    (3) method (M1) for the synthesis of a layered lithium metal oxide composition involving precipitating a mixed metal hydroxide or carbonate composition from a solution comprising +2 metal cations, where the mixed metal hydroxide or carbonate composition has a selected stoichiometry comprising Ni+2, Mn+2, Co+2 with a dopant concentration of 0.1-10 mole.%, where the dopant comprises magnesium, calcium, strontium, barium, zinc and/or cadmium.