Housing for a sealed electrochemical battery cell

• US 20050244706A1
• Filed: 04/28/2004
• Published: 11/03/2005
• Est. Priority Date: 04/28/2004
• Status: Active Grant

• Current Assignee: Energizer Brands, LLC (Energizer Holdings, Inc.)
• Original Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Inventors: Wu, James X., Langan, Richard A.
• Granted Patent: US 7,687,189 B2
• Time in Patent Office: Days
• US Class Current: 429/56
• CPC Class Codes: H01M 50/167 by crimping
• CPC Class Codes: H01M 50/171 using adhesives or sealing agents
• CPC Class Codes: H01M 50/3425 in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
• CPC Class Codes: H01M 50/538 Connection of several leads or tabs of wound or folded electrode stacks
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An electrochemical cell with a collector assembly for sealing the open end of a cell container. The collector assembly includes a retainer and a contact spring with a peripheral flange, each having a central opening therein. A pressure release vent member disposed between the retainer and the peripheral flange of the contact spring seals the openings in the retainer and contact spring under normal conditions and ruptures to release pressure from within the cell when the internal pressure exceeds a predetermined limit.

Claims

1. An electrochemical battery cell comprising a housing, an electrode assembly comprising a positive electrode, a negative electrode and a separator disposed between the electrodes, and an electrolyte, the housing comprising:

a container with an open end in which the electrode assembly and electrolyte are disposed; and

a collector assembly disposed between the electrode assembly and the open end of housing, the collector assembly comprising;

a retainer that defines a first opening;

a contact spring comprising a peripheral flange that defines a second opening, the first and second opening defining a pressure release channel; and

a pressure release vent member having a peripheral portion disposed between the retainer and the contact spring and closing the pressure release channel, the pressure release vent member capable of rupturing in response to internal cell pressure that is at least as high as a predetermined release pressure thereby allowing matter to escape through the first opening of the retainer.

2. The cell of claim 1, wherein the pressure release vent member comprises at least a first layer of a composition selected from the group consisting of:

metal, polymer, and mixtures thereof.

3. The cell of claim 1, wherein the pressure release vent member has a thickness of 0.254 mm or less.

4. The cell of claim 1, wherein the retainer, the peripheral flange of the contact spring, and the peripheral portion of the pressure release vent member cooperate to form an electrolyte seal within the collector assembly.

5. The cell of claim 4, wherein the peripheral flange of the contact spring forms a continuous annulus.

6. The cell of claim 1, wherein the pressure release vent member comprises a first layer having a vapor transmission rate of electrolyte less than 11.81 g·

mm/(day·

mm²).

7. The cell of claim 2, wherein the pressure release vent member comprises a second layer comprising a composition selected from the group consisting of:

polyethylene, polypropylene, polybutylene terephthalate, polyethylene terephthalate, ethylene acrylic acid, ethylene methacrylic acid, polyethylene methacrylic acid, and mixtures thereof.

8. The cell of claim 7, wherein the pressure release vent member comprises a third layer, the first layer being disposed between the second layer and the third layer, and the third layer comprising a composition selected from the group consisting of:

polyethylene, polypropylene, polybutylene terephthalate, polyethylene terephthalate, ethylene acrylic acid, ethylene methacrylic acid, polyethylene methacrylic acid, and mixtures thereof.

9. The cell of claim 8, wherein the first layer comprises aluminum.

10. The cell of claim 1, wherein the collector assembly comprises a first gasket disposed against the container and wherein the gasket, the retainer, the contact spring and the pressure release vent member are compressed together thereby providing a seal between the retainer and the contact spring.

11. The cell of claim 1, wherein the collector assembly comprises a second gasket disposed between the retainer and at least one of the contact spring and the pressure release vent member.

12. The cell of claim 1, wherein the peripheral flange of the contact spring comprises a continuous flange, surrounding the first opening, the continuous flange having a continuous projection thereon.

13. The cell of claim 1, wherein the retainer and the pressure release vent member are bonded together.

14. The cell of claim 12, wherein the contact spring and the pressure release vent member are bonded together.

15. The cell of claim 1, wherein the pressure release vent member ruptures at a pressure that ranges from 10.5 kg/cm² to 42.3 kg/cm² at a temperature that ranges from 20°

C. to 25°

C.

16. The cell of claim 1, wherein the pressure release vent member comprises a layer of a composition comprising aluminum, and the pressure release vent member has a maximum thickness of 0.254 mm.

17. The cell of claim 16, wherein the pressure release vent member comprises a second layer and a third layer of a composition selected from the group consisting of polyethylene, polypropylene, polybutylene terephthalate, polyethylene terephthalate, ethylene acrylic acid, ethylene methacrylic acid, polyethylene methacrylic acid, and mixtures thereof.

18. The cell of claim 17, wherein the cell further comprises a contact terminal and a positive temperature coefficient device disposed between the contact terminal and the retainer.

19. The cell of claim 18, wherein the positive electrode comprises FeS₂ and the negative electrode comprises lithium metal.

20. The cell of claim 19, wherein the retainer has a peripheral edge that is substantially circular.

21. The cell of claim 20, wherein the housing is cylindrical.

22. An electrochemical battery cell comprising a housing, an electrode assembly comprising a positive electrode, a negative electrode and a separator disposed between the electrodes, and an electrolyte, the housing comprising:

a container with an open end in which the electrode assembly and electrolyte are disposed; and

a collector assembly disposed between the electrode assembly and the open end of housing, the collector assembly comprising;

a retainer that defines a first opening;

a contact spring comprising a peripheral flange that defines a second opening, the first and second opening defining an pressure release channel; and

a pressure release vent member having a peripheral portion disposed between the retainer and the contact spring and closing the pressure release channel between the first opening and the second opening, the pressure release vent member capable of rupturing in response to internal cell pressure that is at least as high as a predetermined release pressure thereby allowing matter to escape through the first opening of the retainer; and

wherein the retainer and the contact spring flange cooperate with the pressure release vent member to form a seal between the pressure release vent member and the retainer.

23. The cell of claim 22, wherein the burst pressure of the pressure release vent member ranges from 10.5 kg/cm² to 42.3 kg/cm² at a temperature that ranges from 20°

C. to 25°

C.

24. The cell of claim 22, wherein the pressure release vent member comprises at least a first layer of a composition selected from the group consisting of:

metal, polymer and mixtures thereof.

25. The cell of claim 24, wherein a first layer of the pressure release vent member comprises aluminum.

26. The cell of claim 25, wherein the pressure release vent member comprises a second layer comprising a composition selected from the group consisting of:

polyethylene, polypropylene, polybutylene terephthalate, polyethylene terephthalate, ethylene acrylic acid, ethylene methacrylic acid, polyethylene methacrylic acid, and mixtures thereof.

27. The cell of claim 26, wherein the pressure release vent member comprises a third layer, the first layer being disposed between the second layer and a third layer, and the third layer comprising a composition selected from the group consisting of:

polyethylene, polypropylene, polybutylene terephthalate, polyethylene terephthalate, ethylene acrylic acid, ethylene methacrylic acid, polyethylene methacrylic acid, and mixtures thereof.

28. The cell of claim 27, wherein the second layer comprises polyethylene and the third layer comprises polyethylene.

29. The cell of claim 22, wherein the peripheral flange of the contact spring comprises a continuous flange surrounding the first opening, the continuous flange having a continuous projection thereon.

30. The cell of claim 22, wherein the retainer has a crimp that applies a compressive force to the pressure release vent member and the contact spring.

31. The cell of claim 29, wherein the retainer has a crimp that applies a compressive force to the peripheral portion of the pressure release vent member and the peripheral flange of the contact spring.

32. The cell of claim 31, wherein the collector assembly further comprises:

a contact terminal;

a gasket; and

a positive temperature coefficient device disposed between the contact terminal and the retainer.

33. The cell of claim 32, wherein the retainer and the pressure release vent member are bonded together.

34. The cell of claim 33, wherein the positive electrode comprises FeS₂ and the negative electrode comprises lithium metal.

35. The cell of claim 33, wherein the retainer has a peripheral edge that is substantially circular.

36. The cell of claim 33, wherein the housing is cylindrical.

37. An electrochemical battery cell comprising a housing, an electrode assembly comprising a positive electrode, a negative electrode and a separator disposed between the electrodes, and an electrolyte, the housing comprising:

a container with an open end in which the electrode assembly and electrolyte are disposed; and

a collector assembly disposed between the electrode assembly and the open end of housing, the collector assembly comprising;

a retainer that defines a first opening;

a contact spring comprising a peripheral flange that defines a second opening, the first and second openings defining a pressure release channel;

a pressure release vent member having a peripheral portion disposed between the retainer and the contact spring and closing the pressure release channel disposed between the first opening and the second opening, the pressure release vent member capable of rupturing in response to internal cell pressure that is at least as high as a predetermined release pressure thereby allowing matter to escape through the first opening of the retainer; and

a sealing means between the pressure release vent member and the retainer.

38. The cell of claim 37, wherein the sealing means comprises a compressive force produced by cooperation of the retainer, the peripheral flange of the contact spring and the peripheral portion of the pressure release vent member.

39. The cell of claim 38, wherein the sealing means comprises a crimp in the retainer about the peripheral flange of the contact spring and the peripheral portion of the pressure release vent member.

40. The cell of claim 39, wherein collector assembly comprises a means for maintaining a seal between the pressure release vent member and the retainer when the compressive force between the pressure release vent member and the retainer is reduced.

41. The cell of claim 40, wherein the means for maintaining a seal between the pressure release vent member and the retainer comprises a continuous projection within the peripheral flange of the contact spring that completely surrounds the second opening.

42. The cell of claim 37, wherein the positive electrode comprises FeS₂ and the negative electrode comprises lithium metal.