High energy cathodes for lithium ion batteries

1. An electrode, comprising:

a material represented by Li 1-x M x Co 1-y M′ y O 2-d where 0<x≤0.2, 0≤y<1, and 0<d≤0.2;

wherein M and M′ each independently comprises a metal selected from the group consisting of transition metals, Group I elements, and Group II elements and wherein M is present in a lithium site of the material.

2. The electrode of claim 1 , wherein M is magnesium.

3. The electrode of claim 1 , wherein M is zirconium.

4. The electrode of claim 1 , wherein M is niobium.

5. The electrode of claim 1 , wherein M is sodium.

6. The electrode of claim 1 , wherein 0<x≤0.01.

7. The electrode of claim 1 , wherein 0.01<x≤0.02.

8. The electrode of claim 1 , wherein 0.02<x≤0.03.

9. The electrode of claim 1 , wherein 0.03<x≤0.04.

10. The electrode of claim 1 , wherein 0.04<x≤0.05.

11. The electrode of claim 1 , wherein 0.05<x≤0.06.

12. The electrode of claim 1 , wherein y=0.

13. The electrode of claim 1 , wherein the material comprises Li 0.95 Zr 0.05 CoO 2 .

14. The electrode of claim 1 , wherein the material comprises Li 0.99 Mg 0.01 CoO 2 .

15. The electrode of claim 1 , wherein M′ is a transition metal.

16. The electrode of claim 1 , wherein 0<y≤0.01.

17. The electrode of claim 1 , wherein 0.01<y≤0.02.

18. The electrode of claim 1 , wherein 0.02<y≤0.03.

19. The electrode of claim 1 , wherein 0.03<y≤0.04.

20. The electrode of claim 1 , wherein 0.04<y≤0.05.

21. The electrode of claim 1 , wherein 0.05<y≤0.06.