Electrode materials and lithium battery systems

1. A material comprising a lithium titanate comprising a plurality of primary particles and secondary particles, wherein

the average primary particle size is about 5 nm to about 100 nm; and

the average secondary particle size is less than 1 μm.

2. The material of claim 1 , wherein the lithium titanate further comprises a carbon-coating.

3. The material of claim 2 , wherein the carbon-coating is present at about 20 wt % or less based on the total weight of the material.

4. The material of claim 2 , wherein the carbon-coating is present at about 5 wt % or less based on the total weight of the material.

5. The material of claim 2 , wherein the carbon-coating is present at about 2 wt % or less based on the total weight of the material.

6. The material of claim 1 , wherein the lithium titanate is Li 4 Ti 5 O 12 .

7. A method of preparing the lithium titanate of claim 1 comprising:

a) mixing a source of lithium ions and a source of titanium ions in a solvent;

b) removing the solvent to form a solid mixture; and

c) calcining the solid mixture.

8. The method of claim 7 , wherein the solvent is selected from carboxylic acids, alcohols, esters, ethers, ketones, and a mixture of any two or more thereof.

9. The method of claim 7 , wherein the source of lithium ions is selected from lithium oxide, lithium peroxide, lithium hydroxide, lithium carbonate, lithium nitrate, lithium oxalate, lithium acetate, lithium chloride, lithium fluoride, lithium iodide, and a mixture of any two or more thereof.

10. The method of claim 7 , wherein the source of titanium ions is selected from anatase titanium oxide, rutile titanium oxide, a titanium-ion solution wherein the solution is aqueous, a titanium-ion solution wherein the solution is organic, a titanium-ion solution wherein the solution is a mixture of aqueous and organic solutions, and a mixture of any two or more thereof.

11. The method of claim 7 , further comprising crushing the solid mixture prior to calcining the solid mixture.

12. The method of claim 7 , wherein the calcining is at a temperature from about 600° C. to about 1000° C.

13. The method of claim 7 further comprising coating the particles of lithium titanate with a layer of carbon.

14. The method of claim 13 , wherein the coating the particles of lithium titanate with a layer of carbon further comprises:

exposing the lithium titanate to a carbon source in a furnace; and

heating the carbon source to deposit carbon on the lithium titanate.

15. The method of claim 14 , wherein the heating is from about 100° C. to about 1300° C.

16. The method of claim 14 , wherein the carbon source comprises from 1 to about 20 carbon atoms, and is selected from acetylene, butane, 1,3 butadiene, 1-butene, cis-2-butene, trans-2-butene, 2,2-dimethylpropane, ethane, ethylene, hexane, heptane, isobutane, isobutylene, methane, 2-methylbutane, pentane, propane, propylene, octane, toluene, and a mixture of any two or more thereof.

17. The method of claim 14 , wherein the carbon source is mixed with a carrier gas selected from carbon dioxide, nitrogen, helium, argon, or a mixture of any two or more thereof.

18. The method of claim 7 , wherein the calcined mixture is Li 4 Ti 5 O 12 .

19. A negative electrode comprising:

the lithium titanate of claim 1 ;

a current collector; and

a binder;

wherein the lithium titanate is coated onto the current collector.

20. An electrochemical device comprising:

the electrode of claim 19 ;

a positive electrode; and

a non-aqueous electrolyte.

21. An electrochemical device comprising the material of claim 1 coated on an current collector comprising aluminum.