An electrochemical cell is provided with an enhanced pressure relief vent
formed in a closed end of the cell container that allows for effective
venting of gas from the closed end of the container. The cell includes 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. The cell has a positive electrode, a negative electrode, and an
aqueous alkaline electrolyte, all disposed in the container. The cell
further includes a pressure relief vent mechanism having a reduced
thickness groove formed in the end wall of the container. A cover is
welded to the closed end wall of the container over the pressure relief
vent mechanism and is welded via at least three welds, wherein two
adjacent welds are angularly separated by more than 120.degree..