Alkaline cell with flat housing

A primary alkaline cell comprising a negative and a positive terminal, and an outer housing having a pair of opposing flat sides running along a portion of the length of said housing;

• said housing having a closed end and opposing open end and said housing not having any integral cylindrical sections;
• said cell further comprising an anode comprising zinc and a cathode comprising MnO2 within said housing, a separator between said anode and cathode, and an end cap assembly sealing the open end of said housing;
• wherein the cathode comprises at least one cathode slab having an opening defined therethrough devoid of cathode material, with at least a portion of the outer surface of said cathode contacting the inside surface of said housing,
• said end cap assembly sealing the open end of said housing thereby forming a boundary surface around the cell interior;
• wherein the cathode comprises a plurality of rectangular shaped cathode slabs;
• wherein each of said slabs has a central opening devoid of cathode material;
• wherein said cathode slabs are stacked within the housing along the cell's central longitudinal axis so that said openings devoid of cathode material form a central core along said longitudinal axis, with the outer surface of said cathode contacting the inside surface of said housing;
• wherein said cell comprises a vent mechanism located on said the boundary surface, wherein said vent mechanism activates to release gas pressure from within the cell as said gas pressure rises, said vent mechanism comprising a first and a second rupture zone on said boundary surface, wherein at least one of said rupture zones forms a groove on said boundary surface and the second rupture zone forms a weld on said boundary surface, wherein said rupture zones have the property that the first zone ruptures when gas pressure within the cell rises to a first pressure level and said second zone ruptures when gas pressure within the cell rises to a second pressure level being higher than said first pressure level allowing gas from within the cell to escape from the cell interior through said ruptures.