LAYER-LAYER LITHIUM RICH COMPLEX METAL OXIDES WITH HIGH SPECIFIC CAPACITY AND EXCELLENT CYCLING

摘要

Lithium rich and manganese rich lithium metal oxides are described that provide for excellent performance in lithium-based batteries. The specific compositions can be engineered within a specified range of compositions to provide desired performance characteristics. Selected compositions can provide high values of specific capacity with a reasonably high average voltage. Compositions of particular interest can be represented by the formula, x Li2MnO3.(1−x) Li Niu+ΔMnu−ΔCowAyO2). The compositions undergo significant first cycle irreversible changes, but the compositions cycle stably after the first cycle.

主权项

1. A positive electrode active material for a lithium ion battery having a room temperature specific discharge capacity from 4.6V to 2V of at least about 210 mAh/g at a discharge rate of C/10 and an irreversible capacity loss of no more than about 60 mAh/g, and comprising a layered lithium metal oxide composition approximately represented by the formula x Li2MnO3.(1−x) Li Niu+ΔMnu−ΔCowAyO2, x is at least about 0.2 and no more than about 0.325, 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.