Sealed Nickel-Metal Hydride Batteries for Small Satellite Applications

Sealed, nickel-metal hydride cells are being developed for aerospace applications by Eagle-Picher Industries, Inc. Sizes ranging from 3.5 ampere-hours to 20 ampere-hours are targeted for the small satellite program. The nickel-metal hydride system offers nearly twice the energy density of aerospace nickel-cadmium cells with no memory effect. The cells contain no cadmium, mercury or other toxic materials. The system operates at low pressure and offers significant cost advantages over the nickel-hydrogen system. The cells exhibit excellent overcharge and overdischarge capability with cycle life similar to that of nickel-cadmium. Cells are also being assembled and tested in a number of sizes and designs for use in terrestrial applications.