Electrochemical device and method for producing the same

• US 7,833,656 B2
• Filed: 12/09/2003
• Issued: 11/16/2010
• Est. Priority Date: 12/27/2002
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Ikoma, Munehisa, Saito, Norio, Daio, Fumio, Arai, Naoto, Kaiya, Hideo, Nishimura, Ken, Oshima, Toru
• Primary Examiner(s): Alejandro; Raymond
• Assistant Examiner(s): ROE, CLAIRE L
• Application Number:
  US10/540,867
• Publication Number:
  US 20060035152A1
• Time in Patent Office: 2,534 Days
• Field of Search: 429/179, 429/152, 429/246, 429/68, 429/113, 429/217, 429/218.1, 296231-6235, 427/115, 361503-504, 361/512
• US Class Current: 429/152
• CPC Class Codes: H01M 10/0431 Cells with wound or folded electrodes H01M10/045 takes precedence
• 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 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/66 Selection of materials
• CPC Class Codes: H01M 4/667 in the form of layers, e.g. coatings
• CPC Class Codes: H01M 4/70 characterised by shape or form
• CPC Class Codes: H01M 50/107 having curved cross-section, e.g. round or elliptic H01M50/103, H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 50/586 inside the batteries, e.g. incorrect connections of electrodes
• 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

Abstract

An electrochemical device having an electrode plate assembly. The electrode plate assembly includes (a) at least one first electrode, (b) at least one second electrode, and (c) a separator interposed between the first electrode and the second electrode. The first electrode includes a first current collector sheet and at least one first electrode mixture layer carried thereon. The second electrode includes a second current collector sheet and at least one second electrode mixture layer carried thereon. At least one of the first current collector sheet and the second current collector sheet has a conductive area and an insulating area.

Claims

1. An electrochemical device comprising an electrode plate assembly, said electrode plate assembly comprising,

(a) at least one first electrode,

(b) at least one second electrode, and

(c) a separator interposed between the first electrode and the second electrode,

said first electrode comprising a first current collector sheet and at least one first electrode mixture layer carried thereon,

said second electrode comprising a second current collector sheet and at least one second electrode mixture layer carried thereon,

wherein said electrochemical device further comprises a first terminal electrically connected to said first current collector sheet and a second terminal electrically connected to said second current collector sheet,

said electrode plate assembly has a first side face on which said first terminal is provided and a second side face on which said second terminal is provided,

at least one of said first current collector sheet and said second current collector sheet has a conductive area and an insulating area,

when said first current collector sheet has a conductive area and an insulating area, the conductive area of said first current collector sheet is connected to said first terminal on said first side face, and the insulating area of said first current collector sheet is positioned on said second side face,

when said second current collector sheet has a conductive area and an insulating area, the conductive area of said second current collector sheet is connected to said second terminal on said second side face, and the insulating area of said second current collector sheet is positioned on said first side face,

said first side face has a first insulating material portion for insulating said first terminal from said second electrode, and said second side face has a second insulating material portion for insulating said second terminal from said first electrode,

said first insulating material portion is in contact with said first side face of said second electrode mixture layer, and said second insulating material portion is in contact with said second side face of said first electrode mixture layer, and

said first insulating material portion and said second insulating material portion include at least one selected from the group consisting of resin, glass compositions, and ceramics.

2. The electrochemical device in accordance with claim 1, wherein said first side face and said second side face are positioned on opposite sides of said electrode plate assembly.

3. The electrochemical device in accordance with claim 1, wherein the current collector sheet with said conductive area and said insulating area has a first edge that comprises a part of said conductive area and that does not carry said electrode mixture layer, said conductive area is connected to said first terminal or said second terminal at said first edge, and at least a part of said first edge is buried in said first terminal or said second terminal.

4. The electrochemical device in accordance with claim 1, wherein the current collector sheet with said conductive area and said insulating area has a second edge that comprises a part of said insulating area and that does not carry said electrode mixture layer, said second edge is positioned on said first side face or said second side face, and at least a part of said second edge is buried in said first terminal or said second terminal.

5. The electrochemical device in accordance with claim 1, wherein said electrode plate assembly further comprises a third side face and a fourth side face, and

an edge of said first current collector sheet, an edge of said second current collector sheet, and an edge of said separator are substantially flush with one another on each of said first side face, said second side face, said third side face, and said fourth side face.

6. The electrochemical device in accordance with claim 1, wherein an area S(1) per one side of said first current collector sheet, an area S(2) per one side of said second current collector sheet, and an area S(s) per one side of said separator satisfy the following relations:

S(1)≦

S(s)≦

S(1)×

1.05, and

S(2)≦

S(s)≦

S(2)×

1.05.

16. The electrochemical device in accordance with claim 1, wherein at least one of said first terminal and said second terminal comprises a porous metal film comprising metal particles joined continuously.

17. The electrochemical device in accordance with claim 1, wherein at least one of said first terminal and said second terminal comprises a conductive paste, said conductive paste comprises a resin and a conductive material dispersed in said resin, and said conductive material is in the form of fine particles and/or fiber.

18. The electrochemical device in accordance with claim 1, wherein at least one of said first terminal and said second terminal comprises a low melting-point metal having a melting point of 250°

C. or lower.

19. The electrochemical device in accordance with claim 3, wherein a metal lead is welded to said first terminal or said second terminal in which at least a part of said first edge is buried, and said first edge is in contact with said metal lead.

20. The electrochemical device in accordance with claim 1, wherein at least one of the current collector sheets of outermost two electrodes has a conductive area on both sides and has an electrode mixture layer only on one side facing the inner electrode, and the conductive area on the other side is electrically connected to said first terminal or said second terminal and serves as an extended part of said terminal.

21. The electrochemical device in accordance with claim 5, wherein at least one of said third side face and fourth side face is covered with an electronically insulating porous material.

22. The electrochemical device in accordance with claim 21, wherein said porous material comprises at least one selected from the group consisting of polyolefin, polyalkylene oxide, fluoropolymer and ceramics.

23. The electrochemical device in accordance with claim 21, wherein said porous material comprises a film-shaped member or a coating film of paste.

24. The electrochemical device in accordance with claim 21, wherein the edge of said separator is joined to said porous material on the side face of the electrode plate assembly covered with said porous material.

25. The electrochemical device in accordance with claim 24, wherein said porous material and said separator comprise the same material.

7. An electrochemical device comprising an electrode plate assembly, said electrode plate assembly comprising,

(a) at least one first electrode,

(b) at least one second electrode, and

(c) a separator interposed between the first electrode and the second electrode,

said first electrode comprising a first current collector sheet and at least one first electrode mixture layer carried thereon,

said second electrode comprising a second current collector sheet and at least one second electrode mixture layer carried thereon,

wherein said electrochemical device further comprises a first terminal electrically connected to said first current collector sheet and a second terminal electrically connected to said second current collector sheet,

said electrode plate assembly has a first side face on which said first terminal is provided and a second side face on which said second terminal is provided,

at least one of said first current collector sheet and said second current collector sheet has a conductive area and an insulating area,

when said first current collector sheet has a conductive area and an insulating area, the conductive area of said first current collector sheet is connected to said first terminal on said first side face, and the insulating area of said first current collector sheet is positioned on said second side face,

when said second current collector sheet has a conductive area and an insulating area, the conductive area of said second current collector sheet is connected to said second terminal on said second side face, and the insulating area of said second current collector sheet is positioned on said first side face,

said first electrode mixture layer and said second electrode mixture layer each have an edge covered with an insulating material,

said first side face has a first insulating material portion for insulating said first terminal from said second electrode, and said second side face has a second insulating material portion for insulating said second terminal from said first electrode,

said first insulating material portion is in contact with said first side face of said second electrode mixture layer, and said second insulating material portion is in contact with said second side face of said first electrode mixture layer, and

said first insulating material portion and said second insulating material portion include at least one selected from the group consisting of resin, glass compositions, and ceramics.

8. The electrochemical device in accordance with claim 7, wherein said edge of the first electrode mixture layer covered with the insulating material is positioned on said second side face, and said edge of the second electrode mixture layer covered with the insulating material is positioned on said first side face.

9. The electrochemical device in accordance with claim 7, wherein when said first current collector sheet has a conductive area and an insulating area, the insulating area of said first current collector sheet is adjacent to said edge of the first electrode mixture layer covered with said insulating material, and

when said second current collector sheet has a conductive area and an insulating area, the insulating area of said second current collector sheet is adjacent to said edge of the second electrode mixture layer covered with said insulating material.

26. The electrochemical device in accordance with claim 7, wherein said insulating material comprises at least one selected from the group consisting of a resin coating film and a resin tape.

27. The electrochemical device in accordance with claim 26, wherein said resin coating film is formed by applying a solution or dispersion containing an insulating resin onto an edge of said electrode mixture layer and drying it.

28. The electrochemical device in accordance with claim 27, wherein said insulating resin comprises at least one selected from the group consisting of polyethylene oxide, polypropylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, and a copolymer, polymer alloy or polymer blend including at least one of these.

29. The electrochemical device in accordance with claim 26, wherein said resin coating film is formed by applying a solution or dispersion containing a polymerizable compound onto an edge of said electrode mixture layer and polymerizing said polymerizable compound.

30. The electrochemical device in accordance with claim 29, wherein said polymerizable compound has at least one functional group selected from the group consisting of an acrylate group and a methacrylate group.

31. The electrochemical device in accordance with claim 26, wherein said resin tape comprises an insulating base material and an insulating adhesive carried on said insulating base material.

32. The electrochemical device in accordance with claim 31, wherein said insulating base material comprises at least one selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyimide, aramid resin, and a copolymer, polymer alloy or polymer blend including at least one of these.

10. An electrochemical device comprising an electrode plate assembly, said electrode plate assembly comprising,

(a) at least one first electrode,

(b) at least one second electrode, and

(c) a separator interposed between the first electrode and the second electrode,

said first electrode comprising a first current collector sheet and at least one first electrode mixture layer carried thereon,

said second electrode comprising a second current collector sheet and at least one second electrode mixture layer carried thereon,

wherein said electrochemical device further comprises a first terminal electrically connected to said first current collector sheet, a second terminal electrically connected to said second current collector sheet, and a case accommodating said electrode plate assembly,

said electrode plate assembly has a first side face on which said first terminal is provided and a second side face on which said second terminal is provided,

at least one of said first current collector sheet and said second current collector sheet has a conductive area and an insulating area,

when said first current collector sheet has a conductive area and an insulating area, the conductive area of said first current collector sheet is connected to said first terminal on said first side face, and the insulating area of said first current collector sheet is positioned on said second side face,

when said second current collector sheet has a conductive area and an insulating area, the conductive area of said second current collector sheet is connected to said second terminal on said second side face, and the insulating area of said second current collector sheet is positioned on said first side face,

an inner face of said case is in contact with said first side face and said second side face,

said first side face has a first insulating material portion for insulating said first terminal from said second electrode, and said second side face has a second insulating material portion for insulating said second terminal from said first electrode,

said first insulating material portion is in contact with said first side face of said second electrode mixture layer, and said second insulating material portion is in contact with said second side face of said first electrode mixture layer, and

said first insulating material portion and said second insulating material portion include at least one selected from the group consisting of resin, glass compositions, and ceramics.

11. The electrochemical device in accordance with claim 10, wherein said case comprises a frame and two flat sheets,

said frame surrounds said electrode plate assembly and is in contact with said first side face and said second side face,

and said two flat sheets cover two openings of said frame and are in contact with an upper face and a lower face of said electrode plate assembly.

12. The electrochemical device in accordance with claim 10, wherein said case comprises:

a container with a bottom; and

a flat sheet,

said container accommodates said electrode plate assembly and has side walls in contact with said first side face and said second side face and a bottom in contact with one of an upper face and a lower face of said electrode plate assembly, and

said flat sheet covers an opening of said container and is in contact with the other of the upper face and the lower face of said electrode plate assembly.

13. The electrochemical device in accordance with claim 10, wherein a lead piece is connected to at least one of said first terminal and said second terminal, and said lead piece is drawn out of said case.

14. The electrochemical device in accordance with claim 11, wherein a lead piece is connected to at least one of said first terminal and said second terminal, and said lead piece is drawn out of said case through a slit provided in said frame.

15. The electrochemical device in accordance with claim 12, wherein a lead piece is connected to at least one of said first terminal and said second terminal, and said lead piece is drawn out of said case through a slit provided in said side walls.