Gasket, a bipolar battery and a method for manufacturing a gasket

• US 20080070106A1
• Filed: 08/09/2007
• Published: 03/20/2008
• Est. Priority Date: 11/14/2003
• Status: Active Grant

• Current Assignee: Nilar International AB
• Original Assignee: Nilar International AB
• Inventors: Hock, David, Fredriksson, Lars, Puester, Neil
• Granted Patent: US 8,124,268 B2
• Time in Patent Office: Days
• US Class Current: 429/143
• CPC Class Codes: H01M 10/0418 with bipolar electrodes
• CPC Class Codes: H01M 10/044 with bipolar electrodes
• CPC Class Codes: H01M 10/282 with bipolar electrodes
• CPC Class Codes: H01M 10/287 Small-sized flat cells or batteries for portable equipment H01M10/283 and H01M10/286 take precedence
• CPC Class Codes: H01M 10/30 Nickel accumulators H01M10/34 takes precedence
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 10/347 with solid electrolyte
• CPC Class Codes: H01M 2004/029 Bipolar electrodes
• CPC Class Codes: H01M 4/24 Electrodes for alkaline accumulators
• CPC Class Codes: H01M 4/80 Porous plates, e.g. sintered carriers
• CPC Class Codes: H01M 50/186 characterised by the disposition of the sealing members
• CPC Class Codes: H01M 50/193 Organic material
• CPC Class Codes: H01M 50/30 Arrangements for facilitating escape of gases
• CPC Class Codes: H01M 50/609 Arrangements or processes for filling with liquid, e.g. electrolytes
• CPC Class Codes: H01M 6/42 Grouping of primary cells into batteries H01M6/40 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 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 29/4911 including sealing

Abstract

A gasket 20; 40; 80 for use in a starved electrolyte bipolar battery comprises a structural part 27; 44; 82 in the shape of a frame having an upper surface 1 and a lower surface 2, and at least one channel 23, 24; 83, 84 to permit gas passage through the gasket. The structural part is made from a first material having hydrophobic properties. The gasket 20; 40; 80 further comprises at least a first sealing surface 30; 47; 91 arranged in a closed loop projecting from the upper surface 1, and at least a second sealing surface 30; 47; 92 arranged in a closed loop projecting from the lower surface 2. The first and the second sealing surfaces are provided on at least one sealing part 26; 41, 41; 81, are made from a second material, and the first material of the structural part 27; 44; 82 has a higher elastic modulus than an elastic modulus of the second material of the sealing parts 26; 41, 42; 81. A starved electrolyte bipolar battery and a method for manufacturing a gasket are also disclosed.

Claims

1. A gasket comprising:

a structural part in the shape of a frame and having an upper surface and a lower surface, said structural part being made from a first material having hydrophobic properties;

at least one channel to permit gas passage through the gasket;

at least a first sealing surface arranged in a closed loop projecting from said upper surface;

at least a second sealing surface arranged in a closed loop projecting from said lower surface;

said first and said second sealing surfaces provided on at least one sealing part being made from a second material which is deformable;

the first material of the structural part having a higher elastic modulus than an elastic modulus of said second material of said at least one sealing part.

2. The gasket according to claim 1, wherein said structural part is provided with a rim and a corresponding indentation at an outer surface.

3. The gasket according to claim 1, wherein said first sealing surface and said second sealing surface are provided on a common sealing part attached to an inner surface of said structural part.

4. The gasket according to claim 3, wherein said structural part is provided with projections on said inner surface.

5. The gasket according to claim 3, wherein said at least one channel is provided through the common sealing part between the first and the second sealing surfaces and an inner surface of the common sealing part.

6. The gasket according to claim 5, wherein said at least one channel comprises at least one hole between the first and the second sealing surfaces of the common sealing part, said hole being in communication with the inner surface of said common sealing part.

7. The gasket according to claim 1, wherein said first sealing surface is provided on a first sealing part and said second sealing surface is provided on a second sealing part.

8. The gasket according to claim 7, wherein said at least one channel is provided through the structural part between the upper and the lower surfaces and an inner surface of said structural part.

9. The gasket according to claim 8, wherein said at least one channel comprises at least one hole between the upper and the lower surfaces of the structural part, said hole being in communication with the inner surface of said structural part.

10. The gasket according to claim 9, wherein a third sealing part having a third sealing surface is provided on the upper surface of the structural part and arranged to circumscribe the at least one hole.

11. The gasket according to claim 7, wherein each of the first and the second sealing surfaces comprises a ridge provided along the closed loops of at least the first and the second sealing parts.

12. The gasket according to claim 11, wherein a recess is provided on each side of the ridge along the closed loops of at least the first and the second sealing parts.

13. The gasket according to claim 7, wherein at least one opening is provided between the upper and the lower surfaces of the structural part, and the at least first sealing part and the at least second sealing part are interconnected through said at least one opening.

14. The gasket according to claim 13, wherein multiple openings are provided along the structural part.

15. The gasket according to claim 7, wherein locations of the first and the second sealing parts are at least partially overlapping as projected onto an imaginary plane parallel to the upper surface of the structural part in a direction perpendicular to the upper surface of the structural part.

16. The gasket according to claim 7, wherein locations of the first and the second sealing parts are non-overlapping as projected onto an imaginary plane parallel to the upper surface of the structural part in a direction perpendicular to the upper surface of the structural part.

17. The gasket according to claim 1, wherein the second material has hydrophobic properties.

18. The gasket according to claim 1, wherein the gasket is made through an overmolding injection molding process.

19. A battery comprising:

a case;

a negative endplate in contact with a negative electrode;

a positive endplate in contact with a positive electrode;

at least one set of a negative electrode, a biplate and a positive electrode arranged in a sandwich structure between said negative and said positive endplates;

at least one separator arranged between each negative and positive electrode, said separator including an electrolyte; and

a gasket having

a structural part in the shape of a frame, having an upper surface and a lower surface, and being arranged between each biplate, or between a biplate and the positive and the negative endplates, said structural part being made from a first material having hydrophobic properties,

at least one channel to permit gas passage through the gasket thereby creating a common gas space for a plurality of cells in the battery,

at least a first sealing surface arranged in a closed loop projecting from said upper surface, and

at least a second sealing surface arranged in a closed loop projecting from said lower surface,

said first and said second sealing surfaces provided on at least one sealing part being made from a second material, and

the first material of the structural part having a higher elastic modulus than an elastic modulus of said second material of said at least one sealing part, to provide a sealing to each biplate and the positive and negative endplate, whereby a pressure tight seal of the battery is obtained within the case.

20. The battery according to claim 19, wherein the structural part is provided with a rim and a corresponding indentation at an outer surface, said rim at least partially encompassing the biplate.

21. The battery according to claim 19, wherein said first sealing surface and said second sealing surface are provided on a common sealing part attached to an inner surface of said structural part.

22. The battery according to claim 21, wherein said structural part is provided with projections on said inner surface.

23. The battery according to claim 21, wherein said at least one channel is provided through the common sealing part between the first and the second sealing surfaces and an inner surface of the common sealing part.

24. The gasket according to claim 23, wherein said at least one channel comprises at least one hole between the first and the second sealing surfaces of the common sealing part, said hole being in communication with the inner surface of said common sealing part.

25. The battery according to claim 19, wherein said first sealing surface is provided on a first sealing part and said second sealing surface is provided on a second sealing part.

26. The battery according to claim 25, wherein said at least one channel is provided through the structural part between the upper and the lower surfaces and an inner surface of the structural part.

27. The battery according to claim 26, wherein said at least one channel comprises a hole in the structural part, said hole being in communication with the inside of the pressure tight seal in each cell through the inner surface of the structural part.

28. The battery according to claim 27, wherein a third sealing part having a third sealing surface is provided on the upper surface of the structural part and arranged to circumscribe the hole.

29. The battery according to claim 25, wherein each of the first and the second sealing surfaces comprises a ridge provided along the closed loops of at least the first and the second sealing parts.

30. The battery according to claim 29, wherein a recess is provided on each side of the ridge along the closed loops of at least the first and the second sealing parts.

31. The battery according to claim 25, wherein at least one opening is provided between the upper and the lower surfaces of the structural part, and the at least first sealing part and the at least second sealing part are interconnected through said at least one opening.

32. The battery according to claim 31, wherein multiple openings are provided along the structural part.

33. The battery according to claim 25, wherein locations of the first and the second sealing parts are at least partially overlapping as projected onto an imaginary plane parallel to the upper surface of the structural part in a direction perpendicular to the upper surface of the structural part.

34. The battery according to claim 25, wherein locations of the first and the second sealing parts are non-overlapping as projected onto an imaginary plane parallel to the upper surface of the structural part in a direction perpendicular to the upper surface of the structural part.

35. The battery according to claim 19, wherein the second material of the gasket has hydrophobic properties.

36. The battery according to claim 19, wherein the gasket is made through an overmolding injection molding process.

37. The battery according to claim 19, wherein said battery is a NiMH battery.

38. A method comprising:

a) creating a structural part in the shape of a frame and having an upper surface and a lower surface, said structural part being made from a first material having hydrophobic properties;

b) attaching at least one sealing part having at least a first sealing surface arranged in a closed loop projecting from said upper surface, and at least a second sealing surface arranged in a closed loop projecting from said lower surface, said at least one sealing part being made from a second material;

c) selecting the first material of the structural part to have a higher elastic modulus than an elastic modulus of said second material of said at least one sealing part; and

d) creating at least one channel through said gasket.

39. The method according to claim 38, wherein the channel created in step d) is created through the at least one sealing part.

40. The method according to claim 38, wherein the channel created in step d) is created through the structural part.

41. The method according to claim 38, wherein an injection molding process is used to attach the at least one sealing part to said structural part.

42. The method according to claim 38, wherein the structural part is made through an injection molding process.

43. The method according to claim 38, wherein said first sealing surface and said second sealing surface are provided on a common sealing part attached to an inner surface of said structural part.

44. The method according to claim 43, wherein said structural part is provided with projections on said inner surface.

45. The method according to claim 38, wherein said first sealing surface is provided on a first sealing part, and said second sealing surface is provided on a second sealing part.

46. The method according to claim 45, wherein each of the first and the second sealing surfaces comprises a ridge provided along the closed loops of at least the first and the second sealing parts.

47. The method according to claim 46, wherein a recess is provided on each side of the ridge along the closed loops of at least the first and the second sealing parts.

48. The method according to claim 45, wherein at least one opening is provided between the upper and the lower surfaces of the structural part, and the at least first and the at least second sealing parts are injection molded on said structural part simultaneously through said at least one opening.

49. The method according to claim 48, wherein multiple openings are provided along the structural part.

50. The method according to claim 45, wherein locations of the first and the second sealing parts are at least partially overlapping as projected onto an imaginary plane parallel to the upper surface of the structural part in a direction perpendicular to the upper surface of the structural part.

51. The method according to claim 45, wherein locations of the first and the second sealing parts are non-overlapping as projected onto an imaginary plane parallel to the upper surface of the structural part in a direction perpendicular to the upper surface of the structural part.

52. The method according to claim 38, wherein the second material has hydrophobic properties.

53. The method according to claim 38, wherein the gasket is made through an overmolding injection molding process.