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.
- schematic reproduction
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]).