대표
청구항
▼
We claim: 1. An electrochemical cell having a negative terminal end, comprising: (a) a cylindrical container having an upstanding sidewall presenting an inner and outer surface and a terminal end proximal the negative terminal end of the cell, the container defining a vent extending therethrough; (b) an annular cathode ring disposed within the container, the cathode ring having an inner peripheral sidewall; (c) an ionically permeable separator having an outer surface disposed adjacent the inner peripheral sidewall of the cathode ring and an inner surfac...
We claim: 1. An electrochemical cell having a negative terminal end, comprising: (a) a cylindrical container having an upstanding sidewall presenting an inner and outer surface and a terminal end proximal the negative terminal end of the cell, the container defining a vent extending therethrough; (b) an annular cathode ring disposed within the container, the cathode ring having an inner peripheral sidewall; (c) an ionically permeable separator having an outer surface disposed adjacent the inner peripheral sidewall of the cathode ring and an inner surface defining a central cylindrically shaped void, the container inner surface and the separator outer surface defining a cathode chamber; (d) an anode disposed in the central cylindrically shaped void; (e) a negative current collector electrically connected to the anode and closed at its axially outer end by a negative endplate; and (f) a gasket that extends radially from the negative current collector to the container sidewall, wherein the container is crimped about the gasket to provide a seal therebetween that is removed when internal cell pressure exceeds a predetermined threshold to enable electrolyte to flow out of the cell, the electrolyte being in fluid communication with the vent when the internal cell pressure is greater than the predetermined threshold. 2. The cell as recited in claim 1, wherein the container defines a vent extending therethrough that is sealed by the gasket when the internal cell pressure is less than the predetermined threshold, wherein the seal is removed when the internal cell pressure is greater than the predetermined threshold. 3. The cell as recited in claim 2, further comprising a wrapping that surrounds the outer surface of the container and covers the vent, wherein the wrapping is removed from at least a portion of the container in response to contact with pressurized electrolyte. 4. The cell as recited in claim 3, wherein the gasket includes a flange that abuts the separator and prevents anode from flowing therebetween. 5. The cell as recited in claim 2, wherein the separator prevents the anode from flowing out the vent. 6. The cell as recited in claim 2, wherein the container defines a radially inwardly extending groove that supports the gasket. 7. The cell as recited in claim 6, wherein the gasket is axially compressed against the groove. 8. The cell as recited in claim 2, wherein the gasket further comprises a hub surrounding the negative current collector, a radially outer member disposed adjacent the container, and an arm connecting the hub and the radially outer member. 9. The cell as recited in claim 8, further comprising a washer extending between the hub and the radially outer member to support the seal between the container and the gasket. 10. The cell as recited in claim 9, wherein the washer further supports a seal between the gasket and the negative current collector. 11. The cell as recited in claim 1, wherein a channel extends through the gasket between a cathode chamber and ambient environment, and wherein the channel defines an intake end that is sealed by the container when the internal cell pressure is less than the predetermined threshold. 12. The cell as recited in claim 11, wherein the separator prevents anode from flowing into the channel. 13. The cell as recited in claim 11, wherein the container defines a radially inwardly extending groove that supports the gasket. 14. The cell as recited in claim 13, wherein the gasket is axially compressed against the groove. 15. The cell as recited in claim 14, wherein the channel defines an outlet extending radially with respect to the gasket. 16. The cell as recited in claim 13, wherein the gasket is radially compressed against the groove. 17. The cell as recited in claim 16, wherein the channel defines an outlet that extends axially with respect to the gasket. 18. The cell as recited in claim 11, wherein the gasket further comprises a hub surrounding the negative current collector, and a washer surrounding the hub that biases the hub radially inwardly to seal the hub against the negative current collector. 19. The cell as recited in claim 1, wherein the gasket is translated towards the negative end when the internal cell pressure exceeds the predetermined threshold. 20. The cell as recited in claim 1, wherein the cell is an alkaline cell. 21. The cell as recited in claim 1, wherein the gasket further comprises a hub surrounding the negative current collector, an outer portion disposed adjacent the container, and an arm extending between the hub and the outer portion, wherein the hub does not extend below the arm. 22. A method of venting pressure from an axially extending electrochemical cell of the type having a container defining an interior, a cathode chamber housing a cathode disposed in the interior, an anode disposed within the interior and separated from the cathode via an ionically permeable separator, a vent extending between the interior and an ambient environment, and a gasket disposed adjacent the container to seal the vent, the method comprising the steps of: (A) generating internal cell pressure that exceeds a predetermined pressure threshold; (B) in response to step (A), biasing the gasket axially downstream away from the container; (C) in response to step (B), removing the seal formed between the gasket and the container; and (D) in response to step (C), venting pressurized cell contents into the ambient environment via the vent. 23. The method as recited in claim 22, wherein step (D) further comprises venting pressurized cell contents through an aperture extending through the container. 24. The method as recited in claim 23, further comprising removing a seal formed between the vent and a label surrounding the cell. 25. The method as recited in claim 22, wherein step (D) further comprises venting pressurized cell contents through a channel extending through the gasket between the interior and the ambient environment. 26. The method as recited in claim 22, wherein the gasket remains structurally intact during steps (B) through (D). 27. The method as recited in claim 22, wherein step (B) further includes removing the gasket from a groove extending inwardly from the container. 28. The method as recited in claim 27, wherein the cell is initially crimped to close a negative end of the cell, and wherein step (B) further includes decrimping the cell. 29. A size AAA electrochemical cell disposed in an ambient environment having a negative terminal end, comprising: (a) a cylindrical container having an upstanding sidewall presenting an inner and outer surface and a terminal end proximal the negative terminal end of the cell, wherein the container defines an interior container void; (b) an annular cathode ring disposed within the container void and presenting an inner peripheral sidewall; (c) an ionically permeable separator disposed adjacent the inner peripheral sidewall of the cathode ring and defines a central void; (d) an anode disposed in the central void; (e) a negative current collector electrically connected to the anode and closed at its axially outer end by a negative endplate; and (f) a vent placing the container void in fluid communication with the ambient environment; and (g) a gasket extending radially from the negative current collector to the container sidewall, wherein the negative terminal end defines a negative terminal void disposed between the gasket and the endplate, wherein the negative terminal void has a volume substantially within the range of 0-0.03 cubic centimeters. 30. The size AAA electrochemical cell as recited in claim 29, wherein the terminal void has a volume substantially within the range of 0-0.02 cubic centimeters. 31. The size AAA electrochemical cell as recited in claim 30, wherein the terminal void has a volume substantially within the range of 0-0.01 cubic centimeters. 32. A size AA electrochemical cell disposed in an ambient environment having a negative terminal end, comprising: (a) a cylindrical container having an upstanding sidewall presenting an inner and outer surface and a terminal end proximal the negative terminal end of the cell, wherein the container defines an interior container void; (b) an annular cathode ring disposed within the container void and presenting an inner peripheral sidewall; (c) an ionically permeable separator disposed adjacent the inner peripheral sidewall of the cathode ring and defines a central void; (d) an anode disposed in the central void; (e) a negative current collector electrically connected to the anode and closed at its axially outer end by a negative endplate; and (f) a vent placing the container void in fluid communication with the ambient environment; and (g) a gasket extending radially from the negative current collector to the container sidewall, wherein the negative terminal end defines a negative terminal void disposed between the gasket and the endplate, wherein the negative terminal void has a volume within the range of 0-0.09 cubic centimeters. 33. The size AA electrochemical cell as recited in claim 32, wherein the terminal void has a volume within the range of 0-0.05 cubic centimeters. 34. The size AA electrochemical cell as recited in claim 33, wherein the terminal void has a volume within the range of 0-0.03 cubic centimeters. 35. A size C electrochemical cell disposed in an ambient environment having a negative terminal end, comprising: (a) a cylindrical container having an upstanding sidewall presenting an inner and outer surface and a terminal end proximal the negative terminal end of the cell, wherein the container defines an interior container void; (b) an annular cathode ring disposed within the container void and presenting an inner peripheral sidewall; (c) an ionically permeable separator disposed adjacent the inner peripheral sidewall of the cathode ring and defines a central void; (d) an anode disposed in the central void; (e) a negative current collector electrically connected to the anode and closed at its axially outer end by a negative endplate; and (f) a vent placing the container void in fluid communication with the ambient environment; and (g) a gasket extending radially from the negative current collector to the container sidewall, wherein the negative terminal end defines a negative terminal void disposed between the gasket and the endplate, wherein the negative terminal void has a volume within the range of 0-0.4 cubic centimeters. 36. The size C electrochemical cell as recited in claim 35, wherein the terminal void has a volume substantially within the range of 0-0.3 cubic centimeters. 37. The size C electrochemical cell as recited in claim 36, wherein the terminal void has a volume substantially within the range of 0-0.2 cubic centimeters. 38. The size C electrochemical cell as recited in claim 37, wherein the terminal void has a volume substantially within the range of 0-0.1 cubic centimeters. 39. A size D electrochemical cell disposed in an ambient environment having a negative terminal end, comprising: (a) a cylindrical container having an upstanding sidewall presenting an inner and outer surface and a terminal end proximal the negative terminal end of the cell, wherein the container defines an interior container void; (b) an annular cathode ring disposed within the container void and presenting an inner peripheral sidewall; (c) an ionically permeable separator disposed adjacent the inner peripheral sidewall of the cathode ring and defines a central void; (d) an anode disposed in the central void; (e) a negative current collector electrically connected to the anode and closed at its axially outer end by a negative endplate; and (f) a vent placing the container void in fluid communication with the ambient environment; and (g) a gasket extending radially from the negative current collector to the container sidewall, wherein the negative terminal end defines a negative terminal void disposed between the gasket and the endplate, wherein the negative terminal void has a volume substantially within the range of 0-1.1 cubic centimeters. 40. The size D electrochemical cell as recited in claim 39, wherein the terminal void has a volume substantially within the range of 0-0.7 cubic centimeters. 41. The size D electrochemical cell as recited in claim 40, wherein the terminal void has a volume substantially within the range of 0-0.3 cubic centimeters. 42. The size D electrochemical cell as recited in claim 41 wherein the terminal void has a volume substantially within the range of 0-0.2 cubic centimeters. 43. An electrochemical cell having a negative terminal end, comprising: (a) a cylindrical container having an upstanding sidewall presenting an inner and outer surface and a terminal end proximal the negative terminal end of the cell, the container defining a vent extending therethrough; (b) an annular cathode ring disposed within the container, the cathode ring having an inner peripheral sidewall; (c) an ionically permeable separator having an outer surface disposed adjacent the inner peripheral sidewall of the cathode ring and an inner surface defining a central cylindrically shaped void, the container inner surface and the separator outer surface defining a cathode chamber; (d) an anode disposed in the central cylindrically shaped void; (e) a negative current collector electrically connected to the anode and closed at its axially outer end by a negative endplate; and (f) a gasket that extends radially from the negative current collector to the container sidewall, wherein the container is crimped about the gasket to provide a seal therebetween that is removed when internal cell pressure exceeds a predetermined threshold to enable electrolyte to flow out of the cell, the gasket sealing the vent when the internal cell pressure is less than the predetermined threshold, the seal being removed when the internal cell pressure is greater than the predetermined threshold. 44. The cell as recited in claim 43, further comprising a wrapping that surrounds the outer surface of the container and covers the vent, wherein the wrapping is removed from at least a portion of the container in response to contact with pressurized electrolyte. 45. The cell as recited in claim 43, wherein the separator prevents the anode from flowing out the vent. 46. The cell as recited in claim 45, wherein the gasket includes a flange that abuts the separator and prevents anode from flowing therebetween. 47. The cell as recited in claim 43, wherein the container defines a radially inwardly extending groove that supports the gasket. 48. The cell as recited in claim 47, wherein the gasket is axially compressed against the groove. 49. The cell as recited in claim 43, wherein the gasket further comprises a hub surrounding the negative current collector, a radially outer member disposed adjacent the container, and an arm connecting the hub and the radially outer member. 50. The cell as recited in claim 49, further comprising a washer extending between the hub and the radially outer member to support the seal between the container and the gasket. 51. The cell as recited in claim 50, wherein the washer further supports a seal between the gasket and the negative current collector.
