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Abstract

The present invention includes lithium cobalt oxides having hexagonal layered crystal structures and methods of making same. The lithium cobalt oxides of the invention have the formula LiwCo1-;xAxO2+y wherein 0.96≦w≦1.05, 0≦x≦0.05, -;0.02≦y≦0.02 and A is one or more dopants. The lithium cobalt oxides of the invention preferably have a position within the principal component space defined by the relationship axi+byi≦c, wherein xi={right arrow over (S)}i•{right arrow over (P)}c1; yi={right arrow over (S)}i•{right arrow over (P)}c2; the vector {right arrow over (S)}i is the x-ray spectrum for the LiwCo1-;xAxO2+y compound; the vectors {right arrow over (P)}c1 and {right arrow over (P)}c2 defining the principal component space are determined by measuring the x-ray powder diffraction values {right arrow over (S)}i between 15° and 120° using a 0.02° step size and CuKα rays for a large sample set of lithium cobalt oxides and using the regression of {right arrow over (S)}i of the sample set against the capacity fade after 50 cycles of a lithium coin cell that includes a lithium negative electrode and the lithium cobalt oxide as the positive electrode material and that is cycled between 3.0 and 4.3V at a constant current of C/3 during both charge and discharge cycles; and the values a, b and c are determined by using only the xi and yi values for LiwCo1-;xAxO2+y compounds in the sample set that have a capacity fade after 50 cycles of less than or equal to 15%.

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First Claim