Nickel-Hydrogen Battery Technology-Development and Status

A history of the development of the nickel-hydrogen (Ni-H2) technology at COMSAT Laboratories is presented, starting with the initial exploratory effort in 1970 and extending to the present INTELSAT V Ni-H2 batteries. The latter are based upon the proven reliability of the NTS-2 Ni-H2 cell design and the manufacturing procedures developed to fabricate these cells. This paper compares four different Ni-H2 batteries: the NTS-2 battery, the INTELSAT V flight battery, a 50-A-h battery, and a high-pressure 50-A-h battery. Although all these batteries use the same baseline cell design, the length of the pressure vessel and number of modules in the electrode stack are varied to achieve the desired ampere-hour capacity. Comparisons are made with respect to specific energy, energy per unit volume, structural design, and heat-transfer capability. The maximum specific energy achieved was 60.1 W-h/kg for the high pressure 50-A-h cell.