Lithium titanate structures for lithium ion batteries formed using element selective sputtering

Patent metadata

Field	Value
Publication number	US-10141564-B2
Application number	US-201615087435-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Mar 31, 2016
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A method is provided in which a lithium titanate precursor structure is subjected to element selective sputtering to form a lithium titanate structure including a lithium titanate core and a conformal layer on the lithium titanate core, wherein the conformal layer includes titanium oxide. A method of preparing an electrode for a lithium ion battery, wherein the electrode includes lithium titanate structures, is also provided.

First claim

The invention claimed is:

1. A method, comprising:
subjecting a lithium titanate precursor structure to element selective sputtering to form a lithium titanate structure including a lithium titanate core and a conformal layer on the lithium titanate core, wherein the conformal layer includes titanium oxide and the lithium titanate structure has a surface essentially devoid of lithium.

2. The method as defined in claim 1 wherein the element selective sputtering is performed by any of electron sputtering, plasma sputtering, laser sputtering, and X-ray sputtering.

3. The method as defined in claim 2 wherein the element selective sputtering is performed by plasma sputtering in a rotary plasma system.

4. The method as defined in claim 1 wherein the conformal layer has substantially no lithium.

5. The method as defined in claim 1 , further comprising heat-treating the lithium titanate structure.

6. The method as defined in claim 5 wherein the lithium titanate structure is heat-treated at a temperature ranging from about 400° C. to about 800° C. for a period of time ranging from about 1 hour to about 24 hours.

7. The method as defined in claim 1 , further comprising reducing gas production in a lithium ion battery by:
incorporating a plurality of the lithium titanate structures into a negative electrode;
incorporating the negative electrode into a lithium ion battery; and
cycling the lithium ion battery.

8. A method, comprising:
subjecting a lithium titanate precursor structure to element selective sputtering to form a lithium titanate structure including a lithium titanate core and a conformal layer on the lithium titanate core, wherein the conformal layer includes titanium oxide and the lithium titanate structure has a surface essentially devoid of lithium;
incorporating a plurality of the lithium titanate structures into a negative electrode;
incorporating the negative electrode into a lithium ion battery; and
cycling the lithium ion battery.

9. The method as defined in claim 8 wherein the element selective sputtering is performed by any of electron sputtering, plasma sputtering, laser sputtering, and X-ray sputtering.

10. The method as defined in claim 9 wherein the element selective sputtering is performed by plasma sputtering in a rotary plasma system.

11. The method as defined in claim 8 wherein the conformal layer has substantially no lithium.

12. The method as defined in claim 8 , further comprising heat-treating the lithium titanate structure.

13. The method as defined in claim 12 wherein the lithium titanate structure is heat-treated at a temperature ranging from about 400° C. to about 800° C. for a period of time ranging from about 1 hour to about 24 hours.

14. The method as defined in claim 8 wherein:
the lithium titanate structures are recovered from the element selective sputtering as lithium titanate powder;
the powder is mixed with conductive carbon and polymer binder in a solvent to form a slurry; and
the slurry is coated onto a current collector material and dried to form the negative electrode.

15. The method as defined in claim 8 wherein the negative electrode includes the lithium titanate structures in an amount ranging from about 70 wt. % to about 95 wt. % based on a composition of the negative electrode.

16. The method as defined in claim 8 wherein an average particle size of the lithium titanate structures is 5 μm or less and a surface area of the lithium titanate structures is less than 16 m 2 /g, and wherein the lithium titanate structures have a capacity ranging from about 150 mAh/g to about 170 mA/g.

17. The method as defined in claim 8 wherein the conformal layer has a thickness from about 0.5 nm to about 100 nm.

18. The method as defined in claim 8 wherein the lithium titanate precursor structure is subjected to element selective sputtering for a time of about 1 minute to about 10 minutes.

19. The method as defined in claim 1 wherein the conformal layer has a thickness from about 0.5 nm to about 100 nm.

20. The method as defined in claim 1 wherein the lithium titanate precursor structure is subjected to element selective sputtering for a time of about 1 minute to about 10 minutes.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Liu Zhongyi

Classifications

• H01M4/366

  as layered products · CPC title

• C23C14/082

  of alkaline earth metals · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title

• C04B2235/522

  Oxidic · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title