The anode collector material in cylindrical alkaline cells is usually cartridge brass in the
form of pins or strip. In miniature cells the anode collector is usually a stainless-steel cup
whose convex surface is an exterior terminal of the cell. The outer surface of the cup is
clad with nickel for good electrical contact while its interior, which encloses the anode, is
clad with copper metal. After assembly of either type of cell, the collector surface becomes
coated with zinc as a result of the anode plating action described above. Both the electronic
conductivity of the anode-to-collector interface and the suppression of gassing in the anode
compartment are dependent on this process. In addition to facilitating the zinc-plating action,
mercury, if present, would also fulfill this function. Other measures, such as special cleaning
methods and/or activator-coating the surface, are taken to promote the natural zinc coating
of the collector in mercury-free cells