A nickel–hydrogen battery (NiH₂ or Ni–H₂) is a rechargeable electrochemical power source based on

nickel Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slo ...

and

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

. It differs from a nickel–metal hydride (NiMH) battery by the use of

in gaseous form, stored in a pressurized cell at up to 1200

psi Psi, PSI or Ψ may refer to: Alphabetic letters * Psi (Greek) (Ψ or ψ), the twenty-third letter of the Greek alphabet * Psi (Cyrillic), letter of the early Cyrillic alphabet, adopted from Greek Arts and entertainment * "Psi" as an abbreviat ...

(82.7 bar) pressure. The nickel–hydrogen battery was patented in the United States on February 25, 1971 by Alexandr Ilich Kloss, Vyacheslav Mikhailovic Sergeev and Boris Ioselevich Tsenter from the Soviet Union. NiH₂ cells using 26%

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

(KOH) as an

electrolyte An electrolyte is a substance that conducts electricity through the movement of ions, but not through the movement of electrons. This includes most soluble Salt (chemistry), salts, acids, and Base (chemistry), bases, dissolved in a polar solven ...

have shown a

service life A product's service life is its period of use in service. Several related terms describe more precisely a product's life, from the point of manufacture, storage, and distribution, and eventual use. Service life has been defined as "a product' ...

of 15 years or more at 80% depth of discharge (DOD) The

energy density In physics, energy density is the quotient between the amount of energy stored in a given system or contained in a given region of space and the volume of the system or region considered. Often only the ''useful'' or extractable energy is measure ...

is 75 Wh/ kg, 60 Wh/dm³

specific power Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement ...

220 W/kg.NASA/CR—2001-210563/PART2 -Pag.10
The

open-circuit voltage Open-circuit voltage (abbreviated as OCV or VOC) is the voltage, difference of electrical potential between two Terminal (electronics), terminals of an electronic device when disconnected from any Electric Circuit, circuit. There is no External ...

is 1.55 V, the average voltage during discharge is 1.25 V. While the energy density is only around one third as that of a

lithium battery Lithium battery may refer to: * Lithium metal battery, a non-rechargeable battery with lithium as an anode ** Lithium–air battery ** Lithium–iron disulfide battery ** Lithium–sulfur battery ** Nickel–lithium battery ** Rechargeable li ...

, the distinctive virtue of the nickel–hydrogen battery is its long life: the cells handle more than 20,000

charge cycle A charge cycle is the process of charging a rechargeable battery and discharging it as required into a load. The term is typically used to specify a battery's expected life, as the number of charge cycles affects life more than the mere passage o ...

sFive-year update: nickel hydrogen industry survey
/ref> with 85% energy efficiency and 100% faradaic efficiency. NiH₂

rechargeable batteries A rechargeable battery, storage battery, or secondary cell (formally a type of energy accumulator), is a type of electrical battery which can be charged, discharged into a load, and recharged many times, as opposed to a disposable or prima ...

possess properties which make them attractive for the

energy storage Energy storage is the capture of energy produced at one time for use at a later time to reduce imbalances between energy demand and energy production. A device that stores energy is generally called an Accumulator (energy), accumulator or Batte ...

of electrical energy in satellites and

space probe Uncrewed spacecraft or robotic spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input, such as remote control, or remote guidance. They may also be autonomous, in which th ...

s. For example, the ISS, Mercury Messenger,

Mars Odyssey ''2001 Mars Odyssey'' is a robotic spacecraft orbiting the planet Mars. The project was developed by NASA, and contracted out to Lockheed Martin, with an expected cost for the entire mission of US$297 million. Its mission is to use spectro ...

and the

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American Robotic spacecraft, robotic space probe developed by NASA's Jet Propulsion Laboratory. It launched November 1996 and collected data from 1997 to 2006. MGS was a global mapping mission that examined ...

are equipped with nickel–hydrogen batteries. The

Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...

, when its original batteries were changed in May 2009 more than 19 years after launch, led with the highest number of charge and discharge cycles of any NiH₂ battery in

low Earth orbit A low Earth orbit (LEO) is an geocentric orbit, orbit around Earth with a orbital period, period of 128 minutes or less (making at least 11.25 orbits per day) and an orbital eccentricity, eccentricity less than 0.25. Most of the artificial object ...

History

The development of the nickel hydrogen battery started in 1970 at Comsat and was used for the first time in 1977 aboard the U.S. Navy's Navigation technology satellite-2 (NTS-2). Currently, the major manufacturers of nickel–hydrogen batteries are Eagle-Picher Technologies and Johnson Controls, Inc.

Characteristics

The nickel–hydrogen battery combines the positive nickel electrode of a nickel–cadmium battery and the negative electrode, including the catalyst and gas diffusion elements, of a

fuel cell A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen fuel, hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most bat ...

. During discharge, hydrogen contained in the pressure vessel is oxidized into water while the nickel oxyhydroxide electrode is reduced to nickel hydroxide. Water is consumed at the nickel electrode and produced at the hydrogen electrode, so the concentration of the potassium hydroxide electrolyte does not change. As the battery discharges, the hydrogen pressure drops, providing a reliable state of charge indicator. In one communication satellite battery, the pressure at full charge was over 500 pounds/square inch (3.4 MPa), dropping to only about 15 PSI (0.1 MPa) at full discharge. If the cell is over-charged, the oxygen produced at the nickel electrode reacts with the hydrogen present in the cell and forms water; as a consequence the cells can withstand overcharging as long as the heat generated can be dissipated. The cells have the disadvantage of relatively high self-discharge rate, i.e. chemical reduction of Ni(III) into Ni(II) in the cathode: :NiOOH + 1/2H2 <=> Ni(OH)2 which is proportional to the pressure of hydrogen in the cell; in some designs, 50% of the capacity can be lost after only a few days' storage. Self-discharge is less at lower temperature.David Linden, Thomas Reddy (ed.) ''Handbook of Batteries Third Edition'', McGraw-Hill, 2002 Chapter 32, "Nickel Hydrogen Batteries" Compared with other rechargeable batteries, a nickel–hydrogen battery provides good

specific energy Specific energy or massic energy is energy per unit mass. It is also sometimes called gravimetric energy density, which is not to be confused with energy density, which is defined as energy per unit volume. It is used to quantify, for example, st ...

of 55–60 watt-hours/kg, and very long cycle life (40,000 cycles at 40% DOD) and operating life (> 15 years) in satellite applications. The cells can tolerate overcharging and accidental polarity reversal, and the hydrogen pressure in the cell provides a good indication of the state of charge. However, the gaseous nature of hydrogen means that the volume efficiency is relatively low (60-100 Wh/L for an IPV (individual pressure vessel) cell), and the high pressure required makes for high-cost pressure vessels. The positive electrode is made up of a dry

sintered Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction. Sintering happens as part of a manufacturing process used with metals, ceramics, pla ...

porous nickel plaque, which contains nickel hydroxide. The negative

electrode An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or a gas). In electrochemical cells, electrodes are essential parts that can consist of a varie ...

utilises a teflon-bonded platinum black

catalyst Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

at a loading of 7 mg/cm2 and the separator is knit

zirconia Zirconium dioxide (), sometimes known as zirconia (not to be confused with zirconium silicate or zircon), is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the mineral ba ...

cloth (ZYK-15 Zircar). The Hubble replacement batteries are produced with a wet slurry process where a binder agent and powdered metallic materials are molded and heated to boil off the liquid.

Designs

* Individual pressure vessel (IPV) design consists of a single unit of NiH₂ cells in a pressure vessel. * Common pressure vessel (CPV) design consist of two NiH₂ cell stacks in series in a common pressure vessel. The CPV provides a slightly higher

than the IPV. * Single pressure vessel (SPV) design combines up to 22 cells in series in a single pressure vessel. * Bipolar design is based on thick

s, positive-to-negative back-to-back stacked in a SPV. * Dependent pressure vessel (DPV) cell design offers higher specific energy and reduced cost. * Common/dependent pressure vessel (C/DPV) is a hybrid of the common pressure vessel (CPV) and the dependent pressure vessel (DPV) with a high volumetric efficiency.Common/dependent-pressure-vessel nickel–hydrogen Batteries
/ref> Image:Battery workshop 1993 Fig1 Nickel hydrogen battery.jpg Image:Battery workshop 1993 Fig2 Nickel hydrogen battery.jpg Image:Battery workshop 1993 Fig3 Nickel hydrogen battery.jpg Image:Battery workshop 1993 Fig4 Nickel hydrogen battery.jpg Image:5420miller.jpg

References

External links

Overview of the design, development, and application of nickel–hydrogen batteries

Implantable nickel hydrogen batteries for bio-power applications

NASA handbook for nickel–hydrogen batteries

A nickel/hydrogen battery for terrestrial PV systems

A microfabricated nickel–hydrogen battery using thick film printing techniques
{{DEFAULTSORT:Nickel-hydrogen battery Hydrogen technologies Rechargeable batteries

History

Characteristics

Designs

See also

References

Further reading

External links