HIGH CAPACITY POSITIVE ELECTRODES FOR USE IN LITHIUM-ION ELECTROCHEMICAL CELLS AND METHODS OF MAKING SAME

摘要

Positive electrode for lithium-ion electrochemical cells are provided that have capacity retentions of greater than about 95% after 50 charge-discharge cycles when comparing the capacity after cycle 52 with the capacity after cycle 2 when cycled between 2.5 V and 4.7 V vs. Li/Li+ at 30° C. Compositions useful in the provided positive electrodes can have the formula, Li1+x(NiaMnbCoc)1−xO2, wherein 0.05≦x≦0.10, a+b+c=1, 0.6≦b/a≦1.1, c/(a+b)<0.25, and a, b, and c are all greater than zero. The process of making these positive electrodes includes firing the compositions at 850° C. to 925° C.

主权项

1. A positive electrode for a lithium-ion electrochemical cell comprising a composition having the formula,
Li1+x(NiaMnbCoc)1−xO2, wherein 0.05≦x≦0.10, a+b+c=1, 0.6≦b/a≦1.1, c/(a+b)<0.25, and a, b, and c are all greater than zero, wherein said composition has a capacity retention of greater than about 95% after 50 cycles when comparing the capacity after cycle 52 with the capacity after cycle 2 when cycled between 2.5 V and 4.7 V vs. Li/Li+ at 30° C.