Patent ID: 8158280
Filing Date: 2012-04-17
Classification: H01M,Y02E,Y02P

Abstract:
1. An electrochemical cell comprising: a container having a first end, an open second end, a side wall extending between the first and second ends, a polymeric seal member assembled to the open second end to seal the container closed, and a substantially flat integral end wall extending across the first end; a positive electrode disposed in said container; a negative electrode disposed in said container; an aqueous alkaline electrolyte disposed in said container; a pressure relief vent comprising a reduced thickness groove formed in the end wall of the container, wherein the reduced thickness groove is formed having at least five segments extending radially from a central location, and wherein the at least five segments of the reduced thickness groove are contained within the substantially flat end wall; a cover welded onto the end wall of the container via first, second and third welds and extending over the pressure relief vent; the first, second and third welds located to allow control release of vented gases to outside atmosphere, the first weld is angular spaced 90° from the second weld and the third weld is angular spaced 90° from the second weld and 180° from the first weld; and a peripheral flange of the cover is defined between the third weld and the first weld and has a thickness selected to allow the flange to flex upwards during a proper venting operation.