A nickel/hydrogen battery for solar applications

A nickel/hydrogen battery which was developed for energy storage in communication satellites is described. Advantages offered by this battery include long life, low maintenance, and high reliability. These attributes would also be desirable for terrestrial applications, but the cost is prohibitively high. A 7 kWh battery which is currently being evaluated in a series of solar tests using a photovoltaic array for charging is discussed. It incorporates a number of design changes from aerospace technology that enhance performance of the nickel/hydrogen system for terrestrial service. Individual prismatic cells are housed in a common pressure vessel. Thicker positives are used, which lowers the cost by reducing the number of components as well as increasing specific energy. An electrolyte management system increases cycle life, and a peripheral seal, used as an aid in assembly, enhances oxygen recombination. The use of additives along with a change in electrolyte concentration improves high-temperature performance