Wound electrochemical cell, a method for the manufacture thereof, and use of such electrochemical cells

• US 6,420,065 B1
• Filed: 03/12/1999
• Issued: 07/16/2002
• Est. Priority Date: 07/07/1995
• Status: Expired due to Fees

• Current Assignee: Danionics International A/S, Oticon A/S (William Demant Fonden)
• Original Assignee: Danionics A/S, Oticon A/S (William Demant Fonden)
• Inventors: Yde-Andersen, Steen, Katva, Ilmari
• Primary Examiner(s): Chaney, Carol
• Assistant Examiner(s): DOVE, TRACY MAE
• Application Number:
  US08/983,360
• Time in Patent Office: 1,222 Days
• Field of Search: 429/94, 429/161, 429/162, 429/211, 296/231
• US Class Current: 429/94
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/64 Carriers or collectors
• CPC Class Codes: H01M 4/70 characterised by shape or form
• CPC Class Codes: H01M 6/10 with wound or folded 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
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

The present invention relates to an electrochemical cell composed of a laminate of two electrode structures in the form of current collectors coated with electrode material interposed electrolyte structures. The laminate is wound in a coil, and in at least the initial turn and the final turn, one of the current collectors has a protruding part extending beyond at least one of the edges of the other current collector in the same turn and in the following or previous turn, respectively, and the first current collector has a protruding part extending beyond one of the edges of the second collector foil, the protruding parts of the current collectors along the first and the second edge, respectively, of the laminate are sealed to each other optionally with interposed insulating polymer material.

Claims

1. A wound electrochemical cell formed as a coil with a first and a second coil edge and wound from a laminate having a length and a width, a first and a second edge extending along the length and a first and a second end extending along the width, the laminate being wound in a length direction from the first end to the second end in at least five turns, including an initial turn and a final turn,

the laminate comprises a first electrode structure having a length and a width and a thickness, a first and a second edge extending along the length, and a first and a second end extending along the width, the first electrode structure consisting of a first current collector foil, coated on at least a part of a first and a part of a second side with a first electrode material;

a second electrode structure having a length and a width and a thickness, a first and a second edge extending along the length, and a first and a second end extending along the width, the second electrode structure consists of a second current collector foil, coated on at least a part of a first and a part of a second side with a second electrode material;

an electrolyte structure interposed between the first and the second electrode materials and thereby isolating the first and the second electrode materials from each other;

in at least the final turn and in the next to final turn, the first current collector has a protruding part extending beyond at least the first edge along the length of the second current collector,

in at least the initial turn, the second current collector has a protruding part extending beyond the first edge along the length of the first collector,

the protruding parts of the current collectors along at least the first edge of the laminate are sealed together.

2. A wound electrochemical cell according to claim 1, wherein the first current collector has a protruding part extending beyond the second edge of the second collector foil in at least the final turn.

3. A wound electrochemical cell according to claim 1, wherein one of the first and second electrode materials is an anode material and the other of the first and second electrode materials is a cathode material.

4. A wound electrochemical cell according to claim 1, wherein the electrolyte system comprises:

(a) a salt, wherein said salt is an alkali salt or a quaternary ammonium salt of ClO₄—

, CF₃SO₃—

, AsF₆—

, PF₆—

or BF₄—

, or any mixture of such alkali or ammonium salts;

(b) a solvent selected from a group consisting of alicyclic carbonates, aliphatic carbonates, lactones, esters, glymes and mixtures thereof;

(c) a separator consisting of a porous structure made from a polymer; and

,

(d) a crosslinked or non-crosslinked polymer produced by UV or heat induced polymerization of monomers or oligomers containing one or more polymerizable functional groups.

5. A wound electrochemical cell according to claim 1, wherein the protruding parts of the current collectors of the laminate are sealed to each other by a hot-melt glue.

6. A wound electrochemical cell according to claim 1, wherein the current collectors independently of each other are selected from electrically conductive foils.

7. A wound cell according to claim 6, wherein the thickness of the current collectors is between 5 and 40 μ

m.

8. A wound electrochemical cell according to claim 1, wherein the cathode material comprises as electrochemically active material one or more of spinel lithium manganese oxides, lithium cobalt oxides, lithium nickel oxides, vanadium oxides or titanium disulphide.

9. A wound electrochemical cell according to claim 1, wherein the anode material comprises as electrochemically active material an Li-intercalated carbon material.

10. A wound electrochemical cell according to claim 1, wherein the laminate is wound from 7 to 20 turns.

11. A wound electrochemical cell according to claim 1, wherein the laminate in at least the initial turn consists of the second current collector foil alone, the width of the second current collector foil in at least this initial turn being wider than the first current collector foil and extending beyond one or both of the edges of the first turn of the first current collector foil to form protruding parts, and at least this initial turn of the second current collector foil being non-electrode-coated.

12. A wound electrochemical cell according to claim 1, wherein the laminate in at least the final turn consists of the first current collector foil alone, the width of the first current collector foil in at least this final turn being wider than the second current collector foil and extending beyond both of the edges of the last turn of the second current collector foil to form protruding parts, and at least this final turn of the first current collector foil being non-electrode-coated.

13. A wound electrochemical cell according to claim 11, wherein the protruding parts of the first current collector foil along the first and the second edge of the laminate are sealed to the protruding parts of the second current collector foil along the first and the second edge of the laminate, the sealing extend along a first and a second encircling edge of the cell.

14. A wound electrochemical cell according to claim 11, wherein the cell has an axial hole.

15. A wound electrochemical cell according to claim 11, wherein the protruding parts in at least the final turn of the first current collector along the second edge of the laminate are folded inwardly into an axial hole and sealed to the inner surface of the cell.

16. A method for the manufacture of a wound electrochemical cell as defined in claim 1 comprising the steps of:

i) providing a battery laminate having a length and a width, a first and a second edge extending along its length and a first and a second end extending along its width and comprising

a first electrode structure having a length and a width and a thickness, a first and a second edge extending along its length, and a first and a second end extending along its width, the first electrode structure consisting of a first current collector foil, coated on at least a part of its first and a part of its second side with a first electrode material;

a second electrode structure having a length and a width and a thickness, a first and a second edge extending along its length, and a first and a second end extending along its width, the second electrode structure consisting of a second current collector foil, coated on at least a part of its first and a part of its second side with a second electrode material;

an electrolyte structure interposed between the first and the second electrode materials and thereby isolating the first and the second electrode materials from each other; and

ii) winding said laminate from the first end to the second end in the length direction of the laminate;

in at least the initial turn, the second current collector has a protruding part extending beyond the first edge of the first collector; and

iii) sealing the protruding parts of the current collectors along at least the first edge of the laminate together.

17. A method according to claim 16, wherein the protruding parts are sealed by gluing.

18. A method according to claim 16, wherein the laminate is wound onto a rod-shaped element.

19. A method according to claim 18, further comprising the step of folding protruding parts in at least the final turn of the first current collector foil inwardly along the second edge of the laminate into the axial hole, and sealing these parts to the inner surface of the cell.

20. A method according to claim 16, wherein the laminate is wound onto a flat core.

21. A method according to claim 20, comprising the step of pressing together the protruding parts of the current collectors so as to seal off the cell.

22. A method according to claim 20, comprising the step of winding an electrically insulating cover film onto the wound battery laminate.

23. A wound electrochemical cell according to claim 1, wherein parts of the current collectors are not coated with electrode material and an isolating material is provided for isolating the non-electrode coated parts of the current collectors from each other.

24. A wound electrochemical cell according to claim 1, wherein the protruding parts of the current collectors are at least partly free of electrode material.

25. A wound electrochemical cell according to claim 1, wherein an insulating polymer material is interposed between the protruding parts of the current collectors.

26. A wound electrochemical cell according to claim 2, wherein the protruding parts of the current collectors are at least partly free of electrode material.

27. A wound electrochemical cell according to claim 11, wherein the protruding part in at least the final turn of the first current collector along the first edge of the laminate is folded into sealing contact with the outer surface of the protruding part of the second current collector in the initial turn.

28. A method according to claim 18, further comprising the step of folding the protruding part in at least the final turn of the first current collector along the first edge of the laminate into sealing contact with the outer surface of the protruding part of the second current collector in the initial turn.

29. The wound electrochemical cell of claim 4 wherein the polymer in (d) is non-crosslinked.

30. The wound electrochemical cell of claim 4 wherein the separator is a member selected from the group consisting of polyethylene, polypropylene, polyesters, polycarbonates and cellulose.

31. The wound electrochemical cell of claim 4 wherein the polymer in (d) is selected from the group consisting of non-crosslinkable polyester, polyurethane, polyether and polyacrylate.

32. The wound electrochemical cell of claim 6 wherein at least one of the first and second current collectors are selected from the group consisting of metal foils, aluminum foil, copper foil and nickel foil.

33. The wound electrochemical cell of claim 7 wherein the thickness is between 5 μ

m and 25 μ

m.

34. The wound electrochemical cell of claim 8 wherein the cathode material comprises a member selected from the group consisting of V₆O₁₃ and titanium disulphide.

35. The wound electrochemical cell of claim 10 wherein the laminate is wound from 8 to 15 turns.

36. The method of claim 17 wherein gluing is performed with hot-melt glue.

37. The method of claim 18 wherein the rod-shaped element is a cylindrical mandrel with a substantially cylindrical axial hole.

38. A wound electrochemical cell according to claim 4, wherein the salt is LiAsF₆, LiPF₆, N(Et)₄PF₆, N(Bu)₄PF₆ or any mixtures thereof.