Cathode compositions for lithium-ion batteries

1. A cathode composition for a lithium-ion battery having the formula Li[M 1 (1−x) Mn x ]O 2 where (a) 0<x<0.5 or (b) 0.5<x<1, and M 1 represents one or more metal elements, with the proviso that M 1 is a metal element other than chromium, and when M 1 includes nickel, cobalt, or a combination thereof, all of the nickel has an oxidation state of +2 in air, all of the cobalt has an oxidation state of +3 in air, and all of the manganese has an oxidation state of +4 in air,

said composition characterized as being 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.

2. A cathode composition according to claim 1 wherein M 1 is selected from the group consisting of Ni, Co, Fe, Cu, Li, Zn, V, and combinations thereof.

3. A cathode composition according to claim 1 wherein x=(2−y)/3 and M 1 (1−x) has the formula Li (1−2y)/3 M 2 y , where 0<y<0.5 and M 2 represents one or more metal elements, with the proviso that M 2 is a metal element other than chromium, and when M 2 includes nickel, cobalt, or a combination thereof, all of the nickel has an oxidation state of +2 in air, all of the cobalt has an oxidation state of +3 in air, and all of the manganese has an oxidation state of +4 in air,

said cathode composition having the formula Li[Li (1−2y)/3 M 2 y Mn (2−y)/3 ]O 2 .

4. A cathode composition according to claim 3 wherein 0.083<y<0.5.

5. A cathode composition according to claim 3 wherein 0.167<y<0.5.

6. A cathode composition according to claim 3 wherein M 2 is a single metal element.

7. A cathode composition according to claim 6 wherein M 2 is Ni.

8. A cathode composition according to claim 1 wherein x=(2−2y)/3 and M 1 (1−x) has the formula Li (1−y)/3 M 3 y , where 0<y<0.5 and M 3 represents one or more metal elements, with the proviso that M 3 is a metal element other than chromium, and when M 3 includes nickel, cobalt, or a combination thereof, all of the nickel has an oxidation state of +2 in air, all of the cobalt has an oxidation state of +3 in air, and all of the manganese has an oxidation state of +4 in air,

said cathode composition having the formula Li[Li (1−y)/3 M 3 y Mn (2−2y)/3 ]O 2 .

9. A cathode composition according to claim 8 wherein 0.083<y<0.5.

10. A cathode composition according to claim 8 wherein 0.167<y<0.5.

11. A cathode composition according to claim 8 wherein M 3 is a single metal element.

12. A cathode composition according to claim 11 wherein M 3 is Co.

13. A cathode composition according to claim 1 wherein x=y and M 1 (1−x) has the formula M 4 y M 5 1−2y , where 0<y<0.5, M 4 is a metal element other than chromium, and M 5 is a metal element other than chromium that is different from M 4 , and when M 4 , M 5 , or both includes nickel, cobalt, or a combination thereof, all of the nickel has an oxidation state of +2 in air, all of the cobalt has an oxidation state of +3 in air, and all of the manganese has an oxidation state of +4 in air,

said cathode composition-having the formula Li[M 4 y M 5 1−2y Mn y ]O 2 .

14. A cathode composition according to claim 13 wherein 0.083<y<0.5.

15. A cathode composition according to claim 13 wherein 0.167<y<0.5.

16. A cathode composition according to claim 13 wherein M 4 is Ni.

17. A cathode composition according to claim 13 wherein M 5 is Co.

18. A cathode composition according to claim 13 wherein M 4 is Ni and M 5 is Co.

19. A lithium-ion battery comprising:

(a) an anode;

(b) a cathode according to claim 1 , 3 , 8 , or 13 ; and

(c) an electrolyte separating said anode and said cathodes.