Electrochemical cells

• US 4,430,397 A
• Filed: 07/06/1981
• Issued: 02/07/1984
• Est. Priority Date: 07/06/1981
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Untereker, Darrel F.
• Primary Examiner(s): Walton, Donald L.
• Application Number:
  US06/280,902
• Time in Patent Office: 946 Days
• Field of Search: 429/191, 429/213, 29/623.1
• US Class Current: 429/310
• CPC Class Codes: H01M 4/06 Electrodes for primary cells
• CPC Class Codes: H01M 4/60 of organic compounds
• CPC Class Codes: H01M 6/182 with halogenide as solid electrolyte
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

Electrochemical cells and batteries incorporating iodine-containing cathode materials and cathode current collectors having an interposed viscous fluid layer containing dissolved iodine.

Claims

1. An electrochemical cell comprising anode and cathode means in operative relationship, the cathode means comprising:

an iodine-containing cathode;

cathode current collector means, and

a conductive liquid layer interposed between the cathode and the currect collector for electrically interconnecting the two, the liquid layer comprising iodine dissolved in a solvent.

2. The cell of claim 1 wherein the cathode comprises a mixture of an iodine acceptor component and an organic donor component.

3. The cell of claim 2 wherein the organic component of the cathode is poly(2-vinylpyridine).

4. The cell of claim 3 wherein the ratio of cathode iodine to poly(2-vinylpyridine) is greater than about 20:

1.

5. The cell of claim 4 wherein the ratio is at least 50:

1.

6. The cell of claim 1 wherein the liquid layer is comprised of a polymeric organic material and dissolved iodine.

7. The cell of claim 6 wherein the polymeric organic material is poly(2-vinylpyridine).

8. The cell of claim 7 wherein the cell is treated by a heat soak following its assembly.

9. The cell of claim 6 wherein the polymeric organic material is poly(4-vinylpyridine).

10. The cell of claim 1 wherein the layer is about 1-5 mils thick.

11. The cell of claim 1 wherein the cathode includes poly(4-vinylpyridine).

12. The cell of claim 1 wherein the collector is in the form of a cell container, the cathode mixture is contained in the container and the liquid layer lines the container.

13. The cell of claim 1 wherein the source of the iodine in the liquid layer is the cathode mixture.

14. An electrochemical cell comprising:

anode and cathode means in operative relationship, the cathode means comprising;

an iodine-containing cathode;

a cathode current collector, and

a conductive, preformed body, at least initially upon assembly of the cell, comprised of a polymeric organic material interposed between the cathode and the collector for electrically interconnecting the two upon the dissolution of iodine therein.

15. The cell of claim 14 wherein the cathode material comprises a mixture of iodine and an organic component.

16. The cell of claim 15 wherein the cathodic organic component is poly(2-vinylpyridine).

17. The cell of claim 16 wherein the ratio of iodine to poly(2-vinylpyridine) is greater than 20:

1.

18. The cell of claim 17 wherein the ratio is at least 50:

1.

19. The cell of claim 15 wherein the cathode organic component is poly(4-vinylpyridine).

20. The cell of claim 14 wherein the dissolved iodine is cathode iodine.

21. The cell of claim 14 wherein the polymeric organic material is poly(2-vinylpyridine).

22. The cell of claim 14 wherein the organic material is poly(4-vinylpyridine).

23. The cell of claim 14 wherein the collector is in the form of a cell container, the preformed body is in the form of an envelope lining the container, and the cathode mixture is contained in the envelope.

24. An electrochemical cell, as initially assembled, comprising anode means and cathode means in operative relationship, the cathode comprising:

an iodine-containing cathode;

cathode current collector means, and

a coating on at least those portions of the current collector means adapted for contact with the cathode mixture, the coating being comprised of an organic material for dissolving cathode iodine and forming a conductive interface between the cathode and the collector means.

25. The cell of claim 24 wherein the cathode comprises iodine and an organic component.

26. The cell of claim 25 wherein the organic component is comprised of poly(2-vinylpyridine).

27. The cell of claim 26 wherein the ratio of iodine to poly(2-vinylpyridine) is greater than 20:

1.

28. The cell of claim 27 wherein the ratio is at least 50:

1.

29. The cell of claim 24 wherein the coating is poly(2-vinylpyridine).

30. The cell of claim 24 wherein the coating is poly(4-vinylpyridine).

31. The cell of claim 24 wherein the collector is in the form of a cell container, the coating lines the interior of the container and the cathode mixture is contained therein.

32. The cell of claim 24 wherein the coating is about initially 1-5 mils thick.

33. An improvement in the method of making an electrochemical cell of the type having an iodine-containing cathode and a cathode current collector wherein a coating is provided on the collector, at least on those portions which contact the cathode, of a layer of a polymeric organic material, capable of dissolving cathode iodine and forming a conductive liquid prior to its contact with the cathode.

34. The method of claim 33 wherein the polymeric organic material is poly(2-vinylpyridine).

35. The method of claim 34 wherein the coating is about 1-5 mils thick.

36. The method of claim 34 wherein the polymeric organic material is poly(4-vinylpyridine).

37. The method of claim 36 wherein the coating is about 1-5 mils thick.

38. The method of claim 33 including the step of subjecting the cell components to a heat soak following the coating of the collector and its contact with the cathode.

39. The method of claim 38 wherein the heat soak comprises a temperature of about 100°

C. and a duration of about 1 hour.

40. The method of claim 38 wherein the heat soak step takes place following the final assembly of the cell components.

41. The method of claim 40 wherein the heat soak comprises a temperature of about 100°

C. and a duration of about 1 hour.

52. The method of claim 41 wherein the preformed body is poly(2-vinylpyridine).

42. A method of making an electrochemical cell wherein the cathode comprises an iodine-containing material and a current collector having a contact surface area for contacting the iodine-containing material, comprising the steps of:

providing anode means;

providing a cathode current collector having a contact surface area;

providing an iodine-containing cathode material;

placing a preformed body of polymeric organic material against the contact surface of the current collector, the material being capable of dissolving iodine; and

assembling the anode means, the cathode material, the preformed body and the cathode current collector in electrochemically operative relationship with the preformed body between the cathode material and the current collector.

43. The method of claim 42 wherein the preformed body is poly(2-vinylpyridine).

44. The method of claim 43 wherein the body is about 1-5 mils thick.

45. The method of claim 42 wherein the cathode material comprises poly(2-vinylpyridine) and iodine.

46. The method of claim 45 wherein the ratio of iodine to poly(2-vinylpyridine) is greater than 20:

1.

47. The method of claim 46 wherein the ratio is at least 50:

1.

48. The method of claim 47 wherein the heat soak comprises a temperature of about 100°

C. and a duration of about 1 hour.

49. The method of claim 47 wherein the heat soak step takes place following the final assembly of the cell components.

50. The method of claim 46 wherein the heat soak comprises a temperature of about 100°

C. and a duration of about 1 hour.

51. The method of claim 46 wherein the heat soak step takes place following the final assembly of the cell components.

53. The method of claim 45 including the additional step of subjecting the cell components to a heat soak following the coating of the collector and its contact with the cathode.

54. The method of claim 53 wherein the heat soak comprises a temperature of about 100°

C. and a duration of about 1 hour.

55. The method of claim 45 wherein the heat soak step takes place following the final assembly of the cell components.

56. The method of claim 55 wherein the heat soak comprises a temperature of about 100°

C. and a duration of about 1 hour.

57. The method of claim 42 including the additional step of subjecting the cell components to a heat soak following the coating of the collector and its contact with the cathode.

58. The method of claim 57 wherein the heat soak step takes place following the final assembly of the cell components.

59. The method of claim 58 wherein the heat soak comprises a temperature of about 100°

C. and a duration of about 1 hour.

60. An electrochemical cell comprising anode and cathode means in operative relationship;

the cathode means comprising;

an iodine-containing cathode;

cathode current collector means, and

a quantity of iodine dissolved in a solvent interposed between the cathode and current collector.

61. An electrochemical cell comprising anode and cathode means in operative relationship, the cathode means comprising:

an iodine-containing cathode;

cathode current collector means, and

a quantity of an iodine solvent interposed between the cathode and the current collector.