Negative electrode for lithium battery, method of preparing same, and lithium battery comprising same

• US 20040209159A1
• Filed: 04/09/2004
• Published: 10/21/2004
• Est. Priority Date: 04/17/2003
• Status: Abandoned Application

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Lee, Sang-Mock, Lee, Jong-Ki, Cho, Chung-Kun, Lee, Jea-Woan
• Application Number:
  US10/820,762
• Publication Number:
  US 20040209159A1
• Time in Patent Office: Days
• US Class Current: 429/137
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/5815 Sulfides
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A negative electrode of a lithium battery includes a lithium metal and a protective layer that includes a material having an ion conductivity of at least 5×10⁻⁵ S/cm. The protective layer includes ion conductive material that has a dense internal structure and an effective adhesive strength to the lithium metal. Although the protective layer has a thickness in the order of micrometers, the protective layer does not cause resistance to the electrochemical reaction and is chemically stable with respect to both the lithium metal and the electrolyte.

Claims

1. A negative electrode of a lithium battery comprising a lithium metal, and a protective layer formed on the lithium metal, wherein the protective layer comprises a material having an ion conductivity greater than or equal to 5×

10<sup>−

5</sup> S/cm.

2. The negative electrode of the lithium battery according to claim 1, wherein the protective layer comprises a material having the ion conductivity greater than or equal to 1×

10<sup>−

4</sup> S/cm.

3. The negative electrode of the lithium battery according to claim 1, wherein the protective layer comprises a material having the ion conductivity greater than or equal to 1×

10<sup>−

3</sup> S/cm.

4. The negative electrode of the lithium battery according to claim 1, wherein the material comprising the protective layer comprises a crystalline material.

5. The negative electrode of the lithium battery according to claim 4, wherein the material comprising the protective layer is selected from the group consisting of an oxide, nitride, oxynitride, sulfide, oxysulfide, and halonitride.

6. The negative electrode of the lithium battery according to claim 5, wherein the material comprising the protective layer is selected from the group consisting of Li₃N, LiAlCl₄, Li₉N₂Cl₃, Li_9-xNa_xN₂Cl₃, Li_9-xK_xN₂Cl₃, Li_9-xRb_xN₂Cl₃, Li_9-xCs_xN₂Cl₃, 3Li₃N—

Lil, 3Li₃N—

Nal, 3Li₃N—

Kl, and 3Li₃N—

Rbl (wherein 0<

x<

9).

7. The negative electrode of the lithium battery according to claim 1, wherein the protective layer has a thickness between 500 Å

and 5 μ

m.

8. The negative electrode of the lithium battery according to claim 1, wherein the protective layer has an average surface roughness less than or equal to 5000 Å

.

9. The negative electrode of the lithium battery according to claim 1, wherein the lithium metal one selected from the group consisting of a lithium foil, lithium deposited on a resin film base material and a metal-deposited resin film base material.

10. A method of preparing a negative electrode of a lithium battery, comprising:

depositing lithium on a surface of lithium metal under an atmosphere of at least one gas selected from the group consisting of nitrogen, oxygen, chlorine, carbon monoxide, carbon dioxide, and sulfur dioxide to provide a protective layer comprising a material having an ionic conductivity greater than or equal to 5×

10<sup>−

5</sup> S/cm.

11. The method of preparing the negative electrode of the lithium battery according to claim 10, wherein the material comprising the protective layer is a crystalline material.

12. The method of preparing the negative electrode of the lithium battery according to claim 10, wherein the lithium deposition is carried out by a process selected from the group consisting of sputtering, ion beam sputtering, electron beam evaporation, vacuum thermal evaporation, laser ablation, chemical vapor deposition, thermal evaporation, plasma chemical vapor deposition, laser chemical vapor deposition, and jet vapor deposition.

13. The method of preparing the negative electrode of the lithium battery according to claim 10, further comprising accelerating an ion beam upon depositing the lithium.

14. The method of preparing the negative electrode of the lithium battery according to claim 10, wherein the protective layer comprises a material having the ion conductivity greater than or equal to 1×

10<sup>−

4</sup> S/cm.

15. The method of preparing the negative electrode of the lithium battery according to claim 14, wherein the protective layer comprises a material having the ion conductivity greater than or equal to 1×

10<sup>−

3</sup> S/cm.

16. The method of preparing the negative electrode of the lithium battery according to claim 10, wherein the material composing the protective material is selected from the group consisting of an oxide, nitride, oxynitride, sulfide, oxysulfide, and halonitride.

17. The method of preparing the negative electrode of the lithium battery according to claim 10, wherein the material composing the protective layer is selected from the group consisting of Li₃N, LiAlCl₄, Li₉N₂Cl₃, Li_9-xNa_xN₂Cl₃, Li_9-xK_xN₂Cl₃, Li_9-xRb_xN₂Cl₃, Li_9-xCs_xN₂Cl₃, 3Li₃N—

Lil, 3Li₃N—

Nal, 3Li₃N—

Kl, and 3Li₃N—

Rbl (wherein 0<

x<

9).

18. The method of preparing the negative electrode of the lithium battery according to claim 10, wherein the protective layer has a thickness between 500 Å

and 5 μ

m.

19. The method of preparing the negative electrode of the lithium battery according to claim 10, wherein the protective layer has an average surface roughness less than or equal to 5000 Å

.

20. The method of preparing the negative electrode of the lithium battery according to claim 10, wherein the lithium metal comprises one selected from the group consisting of a lithium foil, lithium deposited on a resin film base material and a metal-deposited resin film base material.

21. A lithium battery comprising a negative electrode comprising a lithium metal, and a protective layer formed on the lithium metal, wherein the protective layer comprises a material having an ion conductivity greater than or equal to 5×

10<sup>−

5</sup> S/cm.

22. The lithium battery according to claim 21, wherein the lithium battery is a lithium-sulfur battery.

23. A lithium battery comprising the negative electrode prepared by depositing lithium on a surface of lithium metal under an atmosphere of at least one gas selected from the group consisting of nitrogen, oxygen, chlorine, carbon monoxide, carbon dioxide, and sulfur dioxide to provide a protective layer comprising a material having an ionic conductivity greater than or equal to 5×

10<sup>−

5</sup> S/cm.

24. The lithium battery according to claim 23, wherein the lithium battery is a lithium-sulfur battery.