Battery having mask which electrochemically inactivates limited surface of metallic component

Abstract

A battery has a metallic component the inner surface of which is in contact with the battery electrolyte and the outer surface of which is not in contact with the electrolyte. To prevent undesired corrosion a mask is placed over a portion of the inner surface in order to electrochemically inactivate the portion of the inner surface covered by it. Although the metallic component having the mask may be the positive electrode or a terminal, preferably it is the negative electrode and preferably the negative electrode is a metallic foil such as zinc, lead, magnesium, or aluminum or alloys thereof. The outer surface of the metallic component opposite the mask may be exposed to the air. An electrical lead may be connected to the outer surface of the metallic component opposite the mask. Where the mask is applied to the inner surface of an electrode, the mask may contain metal or a metalic compound of a chemical composition compatible with the electrode in order to compensate for the loss in electrochemical activity at the surface of the electrode covered by the mask.

Dependencies are inferred from the claim text.