CURRENT STATUS OF NICKEL-HYDROGEN BATTERY TECHNOLOGY DEVELOPMENT

Nickel-hydrogen (NiH2) batteries are widely used in Earth-orbital sate llites. Several advanced NiH2 cell and battery designs are under devel opment, including common pressure vessel (CPV), single pressure vessel (SPV), and dependent pressure vessel designs, Cells are being manufac tured in sizes ranging from 64 to 250 mm in diameter, CPV NiH2 batteri es, utilizing low-cost 64-mm cell diameter technology, have been desig ned and built for several small satellite programs. An advanced 90-mm- diam NiH2 cell design is being manufactured for the space station prog ram, Production 250-mm-diam SPV batteries are currently under construc tion and initial testing has shown excellent results. Cell component l evel development is aimed at reducing battery cost while improving per formance and maintaining reliability and cycle life. NiH2 cycle life t esting is being continued and cells have currently completed more than 95,000 accelerated low-Earth-orbit charge/discharge cycles and 30 ecl ipse seasons in accelerated geosynchronous-Earth-orbit testing, Nickel -metal hydride battery development is continuing for both aerospace an d electric vehicle applications.