Patent ID: 6620543
Filing Date: 2003-09-16
Classification: H01M

Abstract:
An electrochemical cell comprising:a container having a first end, a second end, a side wall extending between the first and second ends, and an end wall extending across the first end; a positive electrode comprising manganese dioxide disposed in said container; a negative electrode comprising zinc disposed in said container; an aqueous alkaline electrolyte disposed in said container; a pressure relief mechanism formed in the end wail of said container for releasing internal pressure from within said container when the internal pressure becomes excessive; and a cover positioned on the end wall of the container in electrical contact therewith and extending over said pressure relief mechanism, said cover including a peripheral flange with a peripheral edge and a protruding nubbin having a contact surface arid an upstanding wail between the contact surface and the peripheral flange; wherein the exterior of the upstanding wall is at a radial distance B, the cover is engaged with the end wall of the container at a location having a radial midpoint at a radial distance C, the exterior of the container side wall is at a radial distance E, radial distances B, C and E are measured from the central longitudinal axis of the cell, when E is greater than or equal to 0.170 inch, the difference Câˆ’B is equal to or less than the difference Eâˆ’C, and when E is less than 0.170, 1.5 times the difference Câˆ’B is equal to or less than the difference Eâˆ’C.