CURRENT COLLECTOR FOR LITHIUM ELECTRODE

• US 20010008725A1
• Filed: 04/28/1998
• Published: 07/19/2001
• Est. Priority Date: 11/19/1993
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: HOWARD, WILLIAM G.
• Granted Patent: US 6,893,772 B2
• Time in Patent Office: Days
• US Class Current: 429/94
• CPC Class Codes: H01M 10/0431 Cells with wound or folded electrodes H01M10/045 takes precedence
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/52 Removing gases inside the secondary cell, e.g. by absorption vent plugs or other mechanical arrangements for facilitating escape of gases H01M50/30
• CPC Class Codes: H01M 16/00 Structural combinations of different types of electrochemical generators
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/405 Alloys based on lithium
• CPC Class Codes: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 4/662 Alloys collectors of lead alloys H01M4/685
• CPC Class Codes: H01M 4/70 characterised by shape or form
• CPC Class Codes: H01M 4/72 Grids
• CPC Class Codes: H01M 4/74 Meshes or woven material; Expanded metal
• CPC Class Codes: H01M 4/742 perforated material
• CPC Class Codes: H01M 50/103 prismatic or rectangular H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 50/466 U-shaped, bag-shaped or folded
• CPC Class Codes: H01M 50/531 Electrode connections inside a battery casing
• CPC Class Codes: H01M 6/10 with wound or folded electrodes
• CPC Class Codes: H01M 6/16 with organic electrolyte H01M6/18 takes precedence
• 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 29/10 : Battery-grid making

Abstract

An electrochemical cell and corresponding electrode assembly are described in which an alkali metal anode and a cathode assembly are wound together in a unidirectional winding having substantially straight sides such that the winding will fit into a prismatic cell. The anode and cathode are preferably arranged in the winding to provide for even utilization of reactive material during cell discharge by placing cathode and anode material in close proximity throughout the electrode assembly in the proportions in which they are utilized. An anode current collector having a length or height shorter than at least one of the length or height of the cathode current collector or alkali metal strips operatively associated with the anode current collector is also described.

Claims

1. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first length of the anode current collector being shorter than the second length of the elongated strip of alkali metal.

2. The electrode assembly of

claim 1

, wherein the first length is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the second length.

3. The electrode assembly of

claim 1

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

4. The electrode assembly of

claim 1

, wherein the cathode current collector is formed of titanium.

5. The electrode assembly of

claim 1

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

6. The electrode assembly of

claim 1

, wherein the solid reactive material is silver vanadium oxide.

7. The electrode assembly of

claim 1

, wherein the binder material is PTFE.

8. The electrode assembly of

claim 1

, wherein the conductivity enhancer is conductive carbon.

9. The electrode assembly of

claim 1

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

10. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first height of the anode current collector being shorter than the second height of the elongated strip of alkali metal.

11. The electrode assembly of

claim 10

, wherein the first length is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the second length.

12. The electrode assembly of

claim 10

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

13. The electrode assembly of

claim 10

, wherein the cathode current collector is formed of titanium.

14. The electrode assembly of

claim 10

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

15. The electrode assembly of

claim 10

, wherein the solid reactive material is silver vanadium oxide.

16. The electrode assembly of

claim 10

, wherein the binder material is PTFE.

17. The electrode assembly of

claim 10

, wherein the conductivity enhancer is conductive carbon.

18. The electrode assembly of

claim 10

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

19. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first length of the anode current collector being shorter than the third length of the cathode current collector.

20. The electrode assembly of

claim 19

, wherein the first length is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third length.

21. The electrode assembly of

claim 19

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

22. The electrode assembly of

claim 19

, wherein the cathode current collector is formed of titanium.

23. The electrode assembly of

claim 19

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

24. The electrode assembly of

claim 19

, wherein the solid reactive material is silver vanadium oxide.

25. The electrode assembly of

claim 19

, wherein the binder material is PTFE.

26. The electrode assembly of

claim 19

, wherein the conductivity enhancer is conductive carbon.

27. The electrode assembly of

claim 19

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

28. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first height of the anode current collector being shorter than the third height of the cathode current collector.

29. The electrode assembly of

claim 28

, wherein the first height is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third height.

30. The electrode assembly of

claim 28

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

31. The electrode assembly of

claim 28

, wherein the cathode current collector is formed of titanium.

32. The electrode assembly of

claim 28

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

33. The electrode assembly of

claim 28

, wherein the solid reactive material is silver vanadium oxide.

34. The electrode assembly of

claim 28

, wherein the binder material is PTFE.

35. The electrode assembly of

claim 28

, wherein the conductivity enhancer is conductive carbon.

36. The electrode assembly of

claim 28

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

37. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first length of the anode current collector being shorter than the second length of the elongated strip of alkali metal, the first height of the anode current collector being shorter than the second height of the elongated strip of alkali metal.

38. The electrode assembly of

claim 37

, wherein the first height is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the second height.

39. The electrode assembly of

claim 37

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

40. The electrode assembly of

claim 37

, wherein the cathode current collector is formed of titanium.

41. The electrode assembly of

claim 37

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

42. The electrode assembly of

claim 37

, wherein the solid reactive material is silver vanadium oxide.

43. The electrode assembly of

claim 37

, wherein the binder material is PTFE.

44. The electrode assembly of

claim 37

, wherein the conductivity enhancer is conductive carbon.

45. The electrode assembly of

claim 37

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

46. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first length of the anode current collector being shorter than the second length of the elongated strip of alkali metal, the first length of the anode current collector being shorter than the third length of the cathode current collector.

47. The electrode assembly of

claim 46

, wherein the first length is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third length.

48. The electrode assembly of

claim 46

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

49. The electrode assembly of

claim 46

, wherein the cathode current collector is formed of titanium.

50. The electrode assembly of

claim 46

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

51. The electrode assembly of

claim 46

, wherein the solid reactive material is silver vanadium oxide.

52. The electrode assembly of

claim 46

, wherein the binder material is PTFE.

53. The electrode assembly of

claim 46

, wherein the conductivity enhancer is conductive carbon.

54. The electrode assembly of

claim 46

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

55. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first length of the anode current collector being shorter than the second length of the elongated strip of alkali metal, the first height of the anode current collector being shorter than the third height of the cathode current collector.

56. The electrode assembly of

claim 55

, wherein the first length is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the second length.

57. The electrode assembly of

claim 55

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

58. The electrode assembly of

claim 55

, wherein the cathode current collector is formed of titanium.

59. The electrode assembly of

claim 55

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

60. The electrode assembly of

claim 55

, wherein the solid reactive material is silver vanadium oxide.

61. The electrode assembly of

claim 55

, wherein the binder material is PTFE.

62. The electrode assembly of

claim 55

, wherein the first height is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third height.

63. The electrode assembly of

claim 55

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

64. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first height of the anode current collector being shorter than the second height of the elongated strip of alkali metal, the first length of the anode current collector being shorter than the third length of the cathode current collector.

65. The electrode assembly of

claim 64

, wherein the first length is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third length.

66. The electrode assembly of

claim 64

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

67. The electrode assembly of

claim 64

, wherein the cathode current collector is formed of titanium.

68. The electrode assembly of

claim 64

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

69. The electrode assembly of

claim 64

, wherein the solid reactive material is silver vanadium oxide.

70. The electrode assembly of

claim 64

, wherein the first height is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the second height.

71. The electrode assembly of

claim 64

, wherein the conductivity enhancer is conductive carbon.

72. The electrode assembly of

claim 64

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

73. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first height of the anode current collector being shorter than the second height of the elongated strip of alkali metal, the first length of the anode current collector being shorter than the third length of the cathode current collector, the first height of the anode current collector being shorter than the third height of the cathode current collector.

74. The electrode assembly of

claim 73

, wherein the first length is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third length.

75. The electrode assembly of

claim 73

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

76. The electrode assembly of

claim 73

, wherein the cathode current collector is formed of titanium.

77. The electrode assembly of

claim 73

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

78. The electrode assembly of

claim 73

, wherein the solid reactive material is silver vanadium oxide.

79. The electrode assembly of

claim 73

, wherein the first height is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third height.

80. The electrode assembly of

claim 73

, wherein the conductivity enhancer is conductive carbon.

81. The electrode assembly of

claim 73

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.

82. An electrode assembly for an electrochemical cell, comprising:

(a) an anode assembly comprising an elongated strip of alkali metal forming an anode and an anode current collector having at least a first connector tab disposed on a first edge thereof, the strip of elongated alkali metal having a first length and a first height, the anode current collector having a second length and a second height;

(b) a cathode assembly, comprising;

(1) a cathode current collector having disposed on a second edge thereof at least a second connector tab, the cathode current collector having a third length and a third height; and

(2) a cathode material bonded to the current collector, the anode and cathode assemblies forming a unidirectional electrode winding having two substantially straight sides, the assemblies having interposed therebetween at least one separator, the first length of the anode current collector being shorter than the third length of the cathode current collector, the first height of the anode current collector being shorter than the third height of the cathode current collector.

83. The electrode assembly of

claim 82

, wherein the first length is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third length.

84. The electrode assembly of

claim 82

, wherein the anode current collector is formed from a material selected from the group consisting of titanium, nickel, copper and alloys thereof.

85. The electrode assembly of

claim 82

, wherein the cathode current collector is formed of titanium.

86. The electrode assembly of

claim 82

, wherein the cathode material comprises a solid reactive material, a binder material and a conductivity enhancer.

87. The electrode assembly of

claim 82

, wherein the solid reactive material is silver vanadium oxide.

88. The electrode assembly of

claim 82

, wherein the first height is about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 15%, about 10%, or about 5% shorter than the third height.

89. The electrode assembly of

claim 82

, wherein the conductivity enhancer is conductive carbon.

90. The electrode assembly of

claim 82

, wherein the separator covers the anode assembly and provides a seal therearound, the pouch having an opening through which the at least first connector tab projects.