Process for stabilising high-purity zinc for primary galvanic cells

摘要

High-purity mercury-free anode zinc in powdered or paste form only exhibits a low tendency to hydrogen gassing if it is exposed for several days to the action of hot alkali metal hydroxide solution at approximately 60 DEG C. Even zinc doped with silver to inhibit corrosion can be "thermostabilised" in this way. The hydroxide solution treatment time is determined by a gassing maximum which occurs in the variation of the action as a function of time and which has to be exceeded. Thereafter a persistant pseudopassivity sets in.