Patent ID: 8465873

Claim:
A positive electrode active material for a lithium ion battery, having a 10 th cycle specific discharge capacity of at least 250 mAh/g at room temperature, a tap density of at least 1.8 g/mL, and substantially spherically shaped particles with substantially uniform size, wherein the specific discharge capacity is determined at a discharge rate of C/3 when discharged from 4.6 volts to 2.0 volts after the material is activated in the first cycle through a charge to 4.6V at a rate of C/10; and comprising a composition having an x-ray diffractogram characteristic of a rock-salt type structure and a formula Li 1+x Ni α Mn β Co γ M″ δ O 2−z F z , where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, γ ranges from about 0.05 to about 0.3, δ ranges from about 0 to about 0.1 and z ranges from about 0 to about 0.1, and where M″ is Mg, Zn, Al, Ga, B, Zr, Ti, Ca, Ce, Y, Nb or combinations thereof.