Development of the large diameter (5.5") nickel-hydrogen battery cell

The nickel-hydrogen (Ni-H₂) battery system is used extensively in the aerospace industry for power storage in Earth-orbital satellites for communications, observation, scientific and military applications. The Ni-H₂ system offers potential cycle life unequaled by any other system. A new technology 5.5 inch diameter Ni-H ₂ cell is being developed for aerospace applications. Based on extensive individual pressure vessel (IPV) technology heritage accumulated from millions of hours of on-orbit performance, the large diameter cell will demonstrate increased specific energy and energy density as well as reduced weight, cost and design risk for the new generation of high power satellites requiring capacities greater than 200 ampere-hours (Ah). In this paper, the authors discuss design features and concepts. Design and production issues and details are discussed with regard to similarities and differences from smaller diameter IPV cells currently in production. They present data from development cells which are currently undergoing life cycle testing to assess the reliability of the product as well as acceptance testing which provides meaningful information about lot to lot consistency achieved in production. Planning and execution of cell and battery qualification testing is discussed. Additionally, the next step in large diameter, high capacity Ni-H₂ IPV cells is presently being developed. This paper discusses design features and examines preliminary test data from that advanced development program