Cathode compositions for lithium-ion batteries
A cathode composition for a lithium-ion battery having the formula Li[M 1 (1-x) Mn x ]O 2 where 0<x<1 and M 1 represents one or more metal elements, with the proviso that M 1 is a metal element other than chromium. The composition is in the form of a single phase having an O3 crystal structure that does not undergo a phase transformation to a spinel crystal structure when incorporated in a lithium-ion battery and cycled for 100 full charge-discharge cycles at 30° C. and a final capacity of 130 mAh/g using a discharge current of 30 mA/g.
1. A cathode composition for a lithium-ion battery selected from cathode compositions in which the cathode composition has the formula Li[M 4 y M 5 1-2y Mn y ]O 2 , wherein 0.083<y<0.5 with the proviso that M 4 and M 5 do not include chromium, and wherein M 4 is Co and M 5 includes the combination of Li and Ni.
2. A cathode composition according to claim 1 wherein M 5 further comprises Co, Fe, Cu, Zn, V, or combinations thereof.
3. A cathode composition according to claim 1 wherein 0.167<y<0.5.
4. A cathode composition according to claim 1 wherein the composition has a c-axis lattice constant of about 14.17 to about 14.28.
5. A cathode composition according to claim 1 wherein M 4 is Co and M 5 includes the combination of Li and Ni, and wherein the composition has a c-axis lattice constant of about 14.20 to about 14.27.
6. A cathode composition according to claim 1 wherein M 4 is Co and M 5 includes the combination of Li and Ni, and wherein the composition has a c-axis lattice constant of about 14.24 to about 14.26.
7. A cathode composition according to claim 1 wherein the composition has a reversible capacity of at least about 200 mAh/g.
8. A cathode composition according to claim 1 wherein the composition has an onset temperature above 185° C. as analyzed by differential scanning calorimetry.