Metal hydride-silver oxide cells

Batteries contain several voltaic cells in series and are classified as primary (e.g., alkaline, mercury, and silver), secondary (e.g., lead-acid, nickel-metal hydride, and lithium-ion), or fuel cell. Supplying electricity to a rechargeable (secondary) battery reverses the redox reaction, forming more reactant for further use. Fuel cells generate a current through the controlled oxidation of a fuel such as H2. 

EEI has used both commercially sintered silver powder with 1-mm-thick electrodes and sintered silver powder with in-house electrodes made from an ABj-type metal-hydride alloy (also known as lanthanum-nickel alloy) using rare earth material for initial laboratory cell test evaluations. Introduction of rare earth material improves the oxidation resistance during the alloy manufacturing process. The ABj-type metal-hydride alloy should be widely used in sealed Ni-MH batteries. The use of rare earth metal lanthanum will provide improved electrical performance, enhanced reliability, and ultra-high longevity for the sealed Ni-MH and Ag-MH battery systems. 

A variation of the nickel-metal hydride cell is the silver-metal hydride cell where the positive nickel oxyhydroxide electrode is replaced by a silver oxide electrode. The silver-metal hydride cell has the advantage of a higher-energy density and better high-rate performance, and may be useful in critical applications where its higher cost and shorter cycle life is acceptable. 

---