High drain rate, primary alkaline cell having a divalent silver oxide/monovalent silver oxide depolarizer blend coated with a layer of silver

摘要

A high drain rate, primary alkaline cell comprising a negative electrode, a divalent silver oxide (AgO)/monovalent silver oxide (Ag.sub. 2 O) depolarizer blend, a separator between said negative electrode and depolarizer blend, and an alkaline electrolyte consisting essentially of potassium hydroxide. The surface of the depolarizer blend adjacent to the separator is coated with a layer of silver. The reduced surface layer of the depolarizer provides improved stability of the depolarizer blend in the alkaline electrolyte, and it provides the cell with a single voltage plateau during discharge. The cell is characterized by a maximum open circuit voltage of about 1.75 volts. The surface of the depolarizer blend can be reduced to form the silver layer either prior to being placed in the cell container or after the blend is consolidated in the container. The amount of divalent silver oxide present in the depolarizer blend is critical, and the blend may contain up to about 70% by weight of divalent silver oxide and still achieve a single voltage plateau during discharge. The cell has a high drain rate capability whereby it can be pulsed, said cell being capable of providing a flash amperage greater than an average of 0.20 amperes per square centimeter of cell cross-sectional area.