This invention relates to pressed nickel electrodes and, more particularly, to such electrodes which utilize NiO.sub.x as the active electrode material.
Heretofore, pressed nickel electrodes have been made by pressing a mixture of active electrode material and binder (and other electrode constituents such as conductive diluents if desired) into the openings of an apertured current collector. The active electrode material may be NiO.sub.x, which is a berthollide, i.e., x is not an integer. A particularly useful NiO.sub.x compound contains about 55% nickel by weight and x has a value between about 1.65 and 1.8. In order to obtain optimum charge acceptance, it has been known to include a cobalt-containing compound with the NiO.sub.x. The cobalt-containing compound may be present in a form such as cobalt hydroxide (Co(OH).sub.2), or it may be present in the form of CoO.sub.x which is analogous to the NiO.sub.x.
Although electrodes formed as described produce satisfactory results in cells such as nickel/iron, nickel/zinc, nickel/hydrogen and nickel/cadmium cells, such cells have to be "formed" by repeated charge/discharge cycling of the cell in order to realize a substantial percentage of the theoretical cell capacity.