Nickel-hydrogen accumulator
A nickel-hydrogen battery (NiH 2 ) is a rechargeable electrochemical voltage source based on nickel and hydrogen . Hydrogen is stored in a pressure cell and is different from nickel-metal hydride batteries . NiH 2 cells are expensive and unwieldy, but have good electrical properties that make them a preferred storage medium for electrical energy in satellites and space probes. For example, were ISS and the Mars Global Surveyor the NASA with nickel-hydrogen batteries equipped.
The energy density is 75 Wh / kg, based on the volume, however, only 60 Wh / dm³. The shelf life is several years. The open circuit voltage is 1.55 V, the voltage under load approx. 1.5 V and the discharge voltage 1.25 V. The cells can withstand more than 20,000 charging cycles. The state of charge can be determined quite precisely using pressure and voltage sensors.
See also
literature
- Albert Zimmerman: Nickel-Hydrogen Batteries: Principles and Practice . The Aerospace Press, El Segundo 2009, ISBN 978-1-884989-20-9 , doi : 10.2514 / 4.989209 ( preview [PDF]).