Lithium Primary Battery and Manufacturing Method Therefor

• US 20090123844A1
• Filed: 10/07/2005
• Published: 05/14/2009
• Est. Priority Date: 11/26/2004
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Morigaki, Kenichi, Ikehata, Toshihiko, Yamanaka, Susumu, Fujii, Shinji, Hitomi, Tohru
• Granted Patent: US 8,062,793 B2
• Time in Patent Office: Days
• US Class Current: 429/231.950
• CPC Class Codes: H01M 2300/0028 characterised by the solvent
• CPC Class Codes: H01M 4/06 Electrodes for primary cells
• CPC Class Codes: H01M 4/08 Processes of manufacture
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/405 Alloys based on lithium
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/5835 Comprising fluorine or fluoride salts
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: H01M 6/16 with organic electrolyte H01M6/18 takes precedence
• CPC Class Codes: H01M 6/164 by the solvent
• CPC Class Codes: H01M 6/166 by the solute
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

A lithium primary battery including a positive electrode, a negative electrode, an organic electrolyte, and a separator interposed between the positive electrode and the negative electrode: the negative electrode including a negative electrode active material; the negative electrode active material being at least one selected from the group consisting of lithium metal and a lithium alloy; at least a surface layer portion of the negative electrode including a composite of amorphous carbon material and the negative electrode active material; and the surface layer portion facing the positive electrode with the separator interposed therebetween.

Claims

1. A lithium primary battery comprising:

a positive electrode, a negative electrode, an organic electrolyte, and a separator interposed between said positive electrode and said negative electrode,

wherein said negative electrode includes a negative electrode active material, said negative electrode active material comprising at least one selected from the group consisting of a lithium metal and a lithium alloy; and

at least a surface layer portion of said negative electrode comprises a composite of an amorphous carbon material and said negative electrode active material, said surface layer portion facing said positive electrode with said separator interposed therebetween.

2. The lithium primary battery in accordance with claim 1, wherein said negative electrode includes said surface layer portion comprising said composite, and a lower layer portion comprising said active material.

3. The lithium primary battery in accordance with claim 1, wherein an amorphous carbon material content in a total of said negative electrode active material and said amorphous carbon material is 5 wt % or less.

4. The lithium primary battery in accordance with claim 1, wherein a thickness of said surface layer portion comprising said composite is ⅓

or less of a thickness of said negative electrode.

5. The lithium primary battery in accordance with claim 1, wherein said positive electrode includes a positive electrode active material, a conductive material, and a binder, said positive electrode active material comprising a metal oxide or graphite fluoride.

6. The lithium primary battery in accordance with claim 1, wherein said amorphous carbon material is microparticles comprising primary particles with an average particle size of 0.1 μ

m or less.

7. The lithium primary battery in accordance with claim 1, wherein said amorphous carbon material is microparticles with a BET specific surface area of 20 m²/g or more.

8. The lithium primary battery in accordance with claim 1, wherein said amorphous carbon material is a carbon black of at least one selected from the group consisting of acetylene black, ketjen black, contact black, furnace black, and lamp black.

9. The lithium primary battery in accordance with claim 1, wherein said organic electrolyte comprises a non-aqueous solvent for dissolving a solute, said solute including lithium tetrafluoroborate, and said non-aqueous solvent including γ

-butyrolactone.

10. A method for manufacturing a lithium primary battery, comprising the steps of:

preparing a negative electrode including a composite of a negative electrode active material and an amorphous carbon material in at least a surface layer portion thereof, said negative electrode active material comprising at least one selected from the group consisting of a lithium metal and a lithium alloy, and

allowing said surface layer portion comprising said composite to face a positive electrode with a separator interposed therebetween.

11. The method for manufacturing a lithium primary battery in accordance with claim 10, wherein said step of preparing a negative electrode including said composite in at least the surface layer portion is carried out in an argon gas atmosphere or in an atmosphere of a reduced pressure of 100 Pa or less.

12. The method for manufacturing a lithium primary battery in accordance with claim 10, wherein said amorphous carbon material is microparticles comprising primary particles with an average particle size of 0.1 μ

m or less.

13. The method for manufacturing a lithium primary battery in accordance with claim 10, wherein said amorphous carbon material is microparticles with a BET specific surface area of 20 m²/g or more.

14. The method for manufacturing a lithium primary battery in accordance with claim 10, wherein said amorphous carbon material is a carbon black of at least one selected from the group consisting of acetylene black, ketjen black, contact black, furnace black, and lamp black.

15. (canceled)

16. A lithium primary battery comprising a positive electrode, a negative electrode, an organic electrolyte, and a separator interposed between said positive electrode and said negative electrode,

said negative electrode includes a negative electrode active material, said negative electrode active material comprising at least one selected from the group consisting of a lithium metal and a lithium alloy;

said negative electrode includes a surface layer portion to which microparticles are embedded, said microparticles comprising primary particles with an average particle size (median size) of 2 μ

m or less, and said surface layer portion facing said positive electrode with said separator interposed therebetween.

17. The lithium primary battery in accordance with claim 16, wherein said microparticles comprise at least one selected from the group consisting of Al₂O₃, Fe₂O₃, SiC, SiO₂, and ZrO₂.

18. The lithium primary battery in accordance with claim 16, wherein said microparticles comprise at least one selected from the group consisting of Li₃PO₄ and Li₂SO₄.

19. The lithium primary battery in accordance with claim 16, wherein said microparticles comprise at least one selected from the group consisting of graphite, petroleum coke, and activated carbon.