Dry cell

The manganese dioxide cathode was dipped in this paste, and both were sealed in a zinc shell, which also acts as the anode.

The first mass-produced model was the Columbia dry cell, first marketed by the National Carbon Company in 1896.

[5] The NCC improved Gassner's model by replacing the plaster of Paris with coiled cardboard, an innovation that leaves more space for the cathode and makes the battery easier to assemble.

By comparison, the first wet cells were typically fragile glass containers with lead rods hanging from the open top and needed careful handling to avoid spillage.

Wet cells have continued to be used for high-drain applications, such as starting internal combustion engines, because inhibiting the electrolyte flow tends to reduce the current capability.

The remaining space between the electrolyte and carbon cathode is taken up by a second paste consisting of ammonium chloride and manganese dioxide, the latter acting as a depolariser.