Fabrication of highly textured lithium cobalt oxide films by rapid thermal annealing

• US 20010014423A1
• Filed: 03/27/2001
• Published: 08/16/2001
• Est. Priority Date: 09/15/1999
• Status: Active Grant

• Current Assignee: UT-Battelle LLC
• Original Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Inventors: Bates, John B.
• Granted Patent: US 6,555,270 B2
• Time in Patent Office: Days
• US Class Current: 429/231.3
• CPC Class Codes: C01G 51/42 containing alkali metals, e.g. LiCoO2
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/74 by peak-intensities or a ratio thereof only
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0426 Sputtering
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/52 of nickel, cobalt or iron
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Systems and methods are described for fabrication of highly textured lithium cobalt oxide films by rapid thermal annealing. A method of forming a lithium cobalt oxide film includes depositing a film of lithium cobalt oxide on a substrate; rapidly heating the film of lithium cobalt oxide to a target temperature; and maintaining the film of lithium cobalt oxide at the target temperature for a target annealing time of at most, approximately 60 minutes. The systems and methods provide advantages because they require less time to implement and are, therefore less costly than previous techniques.

Claims

1. A method of forming an LiCoO₂ film, comprising:

depositing a film of LiCoO₂ on a substrate;

rapidly heating the film of LiCoO₂ to a target temperature; and

maintaining the film of LiCoO₂ at the target temperature for a target annealing time of at most approximately 60 minutes.

2. The method of

claim 1

, wherein the substrate includes at least one material selected from the group consisting of ceramics, semiconductors, and metals.

3. The method of

claim 1

, wherein the target temperature is greater than approximately 700°

C.

4. The method of

claim 1

, wherein the target temperature is at least approximately 800°

C.

5. The method of

claim 1

, wherein the target temperature is at least approximately 850°

C.

6. The method of

claim 1

, wherein the target annealing time is at most approximately 30 minutes.

7. The method of

claim 1

, wherein the target annealing time is approximately 12-17 minutes.

8. The method of

claim 1

, wherein depositing the film includes depositing the film to a thickness of approximately 2.5-3 μ

m.

9. The method of

claim 1

, wherein rapidly heating the film includes heating the film at a rate of at least approximately 50-100°

C./min.

10. The method of

claim 1

, wherein rapidly heating the film includes delivering heat from a quartz lamp.

11. The method of

claim 1

, further comprising:

rapidly cooling the film of LiCoO₂.

12. The method of

claim 11

, wherein rapidly cooling the film of LiCoO₂ includes delivering a cooling jet to the film of LiCoO₂.

13. The method of

claim 12

, wherein rapidly cooling the film of LiCoO₂ includes cooling the film of LiCoO₂ at a rate of approximately 50-100°

C./min.

14. The method of

claim 1

, wherein maintaining the film of LiCoO₂ at the target temperature includes flowing O₂ over the film of LiCoO₂.

22. The method of

claim 1

, wherein maintaining the film of LiCoO₂ at the target temperature for a target annealing time of at most approximately 60 minutes results in a majority of grains oriented with their (101) and (104) planes parallel to the substrate.

15. A cathode made by a process of:

depositing a film of LiCoO₂ on a substrate;

rapidly heating the film of LiCoO₂ to a target temperature; and

maintaining the film of LiCoO₂ at the target temperature for a target annealing time of at most approximately 60 minutes.

16. The cathode of

claim 15

, wherein the substrate includes at least one material from the group consisting of ceramics, semiconductors, and metals.

17. The cathode of

claim 15

, wherein the target temperature is greater than approximately 700°

C.

18. The cathode of

claim 15

, wherein the target temperature is at least approximately 800°

C.

19. The cathode of

claim 15

, wherein the target annealing time is at most approximately 30 minutes.

20. The cathode of

claim 15

, wherein the target annealing time is approximately 12-17 minutes.

21. A battery including the cathode of

claim 15

.

23. The cathode of

claim 15

, wherein a majority of grains are oriented with their (101) and (104) planes parallel to the substrate.

24. A composition, comprising:

a film of LiCoO₂ on a substrate wherein a majority of grains are oriented with their (101) and (104) planes parallel to the substrate.