| abstract |
Lithium rich metal oxyfluorides are described with high specific capacity and, good cycling properties. The materials have particularly good high rate capabilities. The fluorine dopant can be introduced in a low temperature process to yield the materials with desirable cycling properties. In some embodiments, the positive electrode active materials have a composition represented approximately by the formula Li 1+x Ni α Mn β Co γ A δ O 2−z F z where:n x is from about 0.02 to about 0.19, α is from about 0.1 to about 0.4, β is from about 0.35 to about 0.869, γ is from about 0.01 to about 0.2, δ is from 0.0 to about 0.1 and z is from about 0.01 to about 0.2,n nwhere A is Mg, Zn, Al, Ga, B, Zr, Ti, Ca, Ce, Y, Nb or combinations thereof. |