Space Station Freedom Nickel-Hydrogen Cell Development Program

Eight 72 Ah nickel/hydrogen variant cell designs are currently undergoing LEO life testing at Space Systems/Loral. 2000 - 35% DOD LEO cycles have been completed to date. The variant designs incorporate various positive electrode parameters, stack designs, KOH concentration, and platinized/non-platinized wall wicks. BOL data indicates that observed variant performance differences are valid. Observations of effects of the selected parameters on cell performance will be statistically examined as part of continued cell evaluation. The life test is planned to continue for greater than five years.