Patent ID: 8741485

Claim:
A positive electrode active composition for a lithium ion battery having a specific discharge capacity of at least about 230 mAh/g cycled from 4.6 volts to 2.0 volts at a rate of C/3 and comprising a layered lithium metal oxide approximately represented by the formula x Li 2 MnO 3 .(1−x) Li Ni u+Δ Mn u−Δ Co w A y O 2 , x is at least about 0.35 and no more than about 0.425, the absolute value of Δ is no more than about 0.3, 2u+w+y is approximately equal to 1, w is in the range from 0 to 1, u is in the range from 0.2 to 0.5 and y is no more than about 0.1, with the proviso that both (u+Δ ) and w are not zero, wherein an optional fluorine dopant can replace no more than about 10 mole percent of the oxygen.