Mats, nickel hydroxide electrodes

The internal oxygen cycle, formed by oxygen evolution at the nickel-hydroxide electrode and its subsequent reduction at the cadmium electrode, was already detected in the 1940s as a possibility to avoid gas escape during overcharging, and the sealed nickel/cadmium battery appeared on the market in the 1950s. Immobilization of the alkaline electrolyte is achieved by absorption in mats of fibers of polyamide or polypropylene. Formation of a gel, as described in Section... 

---