Secondary cell and method for preparation thereof

• US 6,599,659 B1
• Filed: 08/17/2001
• Issued: 07/29/2003
• Est. Priority Date: 08/18/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kezuka, Koichiro, Endo, Takahiro, Hatazawa, Tsuyonobu
• Primary Examiner(s): Maples, John S.
• Application Number:
  US09/932,049
• Time in Patent Office: 711 Days
• Field of Search: 429/127, 429/209, 429/306, 429/300, 429/245, 429/211, 296/232
• US Class Current: 429/127
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/34 Gastight accumulators
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 2300/0085 Immobilising or gelification of electrolyte
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/663 containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
• CPC Class Codes: H01M 4/667 in the form of layers, e.g. coatings
• CPC Class Codes: H01M 4/806 Nonwoven fibrous fabric containing only fibres
• CPC Class Codes: H01M 50/105 Pouches or flexible bags
• CPC Class Codes: H01M 50/119 Metals
• CPC Class Codes: H01M 50/121 Organic material
• CPC Class Codes: H01M 50/126 comprising three or more layers
• CPC Class Codes: H01M 50/136 Flexibility or foldability
• CPC Class Codes: H01M 50/55 on the same side of the cell
• CPC Class Codes: H01M 50/557 Plate-shaped terminals
• CPC Class Codes: H01M 50/562 characterised by the material
• CPC Class Codes: H01M 50/566 by welding, soldering or brazing
• CPC Class Codes: H01M 50/578 in response to pressure
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/4911 : including sealing

Abstract

A secondary cell exhibiting superior flexibility and cell characteristics. This secondary cell has an anode, a polymer electrolyte layer and an anode, layered together. At least one of the anode and the anode is formed by a sheet-like electrode comprised of a current collector, composed mainly of carbon fibers, and an electrode mixture carried thereon. A metal foil is provided in sliding contact with the sheet electrode on the opposite side of the sheet electrode with respect to the polymer electrolyte layer, and an electrode terminal is taken from said metal foil. The cell device is sealed under a reduced pressure by an exterior member.

Claims

1. A secondary cell having a cathode, a polymer electrolyte layer and an anode, layered together, wherein

at least one of the cathode and the anode is formed by a sheet-like electrode comprised of a current collector, composed mainly of carbon fibers, and an electrode mixture carried thereon;

a metal foil is provided in sliding contact with the sheet electrode on the opposite side of the sheet electrode with respect to the polymer electrolyte layer, an electrode terminal being taken from said metal foil; and

wherein

said cell device is sealed under a reduced pressure by an exterior member.

2. The secondary cell according to claim 1 wherein said cathode includes a layer of a cathode active material capable of doping/undoping lithium ions.

3. The secondary cell according to claim 1 wherein said polymer electrolyte layer is formed of a gel polymer electrolyte.

4. The secondary cell according to claim 1 wherein said exterior member is a laminate film.

5. The secondary cell according to claim 1 wherein said metal foil has an outwardly directing lug on an outer rim thereof.

6. The secondary cell according to claim 1 wherein the cell is a thin-type secondary cell.

7. A method for the preparation of a secondary cell comprising:

sequentially layering a metal foil, from which an electrode terminal is derived, a first electrode, made up of a first current collector, composed mainly of carbon fibers, and an electrode mixture, carried by the first current collector, a polymer electrolyte layer, and a second electrode, made up of a second current collector, carrying a layer of an active material thereon, with the metal foil being in sliding contact with the first electrode, to form a cell device; and

sealing the cell device under a reduced pressure with an exterior member.

8. The method for the preparation of a secondary cell according to claim 7 wherein said first and second electrodes are an anode and a cathode, respectively.

9. The method for the preparation of a secondary cell according to claim 8 wherein a layer of a cathode active material containing an active material capable of doping/undoping lithium ions is formed on said second current collector.

10. The method for the preparation of a secondary cell according to claim 7 wherein said first and second electrodes are a cathode and an anode, respectively.

11. The method for the preparation of a secondary cell according to claim 10 wherein a cathode mixture containing an active material capable of doping/undoping lithium ions is formed on said first current collector.

12. The method for the preparation of a secondary cell according to claim 7 wherein a gel polymer electrolyte is used as said polymer electrolyte layer.

13. The method for the preparation of a secondary cell according to claim 7 wherein a laminate film is used as said exterior member.

14. The method for the preparation of a secondary cell according to claim 7 wherein said metal foil is formed as an outwardly directing lug on an outer rim thereof.