Atomic battery

Source: Wikipedia, the free encyclopedia.
For the generation of radioactive isotopes, see radionuclide generator.

An atomic battery, nuclear battery, radioisotope battery or radioisotope generator is a device which uses energy from the

underwater systems and automated scientific stations in remote parts of the world.[1][2][3]

Nuclear battery technology began in 1913, when Henry Moseley first demonstrated a current generated by charged particle radiation. The field received considerable in-depth research attention for applications requiring long-life power sources for space needs during the 1950s and 1960s. In 1954 RCA researched a small atomic battery for small radio receivers and hearing aids.[4] Since RCA's initial research and development in the early 1950s, many types and methods have been designed to extract electrical energy from nuclear sources. The scientific principles are well known, but modern nano-scale technology and new wide-bandgap semiconductors have created new devices and interesting material properties not previously available.

Nuclear batteries can be classified by

betavoltaic cell
.

Atomic batteries usually have an efficiency of 0.1–5%. High-efficiency betavoltaic devices can reach 6–8% efficiency.[5]

Thermal conversion

Thermionic conversion

A

surface ionization) to neutralize the electron space charge.[6]

Thermoelectric conversion

Main article: Radioisotope thermoelectric generator
Radioisotope-powered cardiac pacemaker being developed by the Atomic Energy Commission, is planned to stimulate the pulsing action of a malfunctioning heart. Circa 1967.

A radioisotope thermoelectric generator (RTG) uses thermocouples. Each thermocouple is formed from two wires of different metals (or other materials). A temperature gradient along the length of each wire produces a voltage gradient from one end of the wire to the other; but the different materials produce different voltages per degree of temperature difference. By connecting the wires at one end, heating that end but cooling the other end, a usable, but small (millivolts), voltage is generated between the unconnected wire ends. In practice, many are connected in series (or in parallel) to generate a larger voltage (or current) from the same heat source, as heat flows from the hot ends to the cold ends. Metal thermocouples have low thermal-to-electrical efficiency. However, the carrier density and charge can be adjusted in semiconductor materials such as bismuth telluride and silicon germanium to achieve much higher conversion efficiencies.[7]

Thermophotovoltaic conversion

TPV Radioisotope Power Conversion Technology development effort is aiming at combining thermophotovoltaic cells concurrently with thermocouples to provide a 3- to 4-fold improvement in system efficiency over current thermoelectric radioisotope generators. [citation needed
]

Stirling generators

Main article: Stirling radioisotope generator

A Stirling radioisotope generator is a Stirling engine driven by the temperature difference produced by a radioisotope. A more efficient version, the advanced Stirling radioisotope generator, was under development by NASA, but was cancelled in 2013 due to large-scale cost overruns.[8]

Non-thermal conversion

Non-thermal converters extract energy from emitted radiation before it is degraded into heat. Unlike thermoelectric and thermionic converters their output does not depend on the temperature difference. Non-thermal generators can be classified by the type of particle used and by the mechanism by which their energy is converted.

Electrostatic conversion

Energy can be extracted from emitted

conductor, thus creating an electrostatic potential. Without a dissipation mode the voltage can increase up to the energy of the radiated particles, which may range from several kilovolts (for beta radiation) up to megavolts (alpha radiation). The built up electrostatic energy
can be turned into usable electricity in one of the following ways.

Direct-charging generator

A direct-charging generator consists of a

fission fragments
may be utilized. Although this form of nuclear-electric generator dates back to 1913, few applications have been found in the past for the extremely low currents and inconveniently high voltages provided by direct-charging generators. Oscillator/transformer systems are employed to reduce the voltages, then rectifiers are used to transform the AC power back to direct current.

English physicist H. G. J. Moseley constructed the first of these. Moseley's apparatus consisted of a glass globe silvered on the inside with a radium emitter mounted on the tip of a wire at the center. The charged particles from the radium created a flow of electricity as they moved quickly from the radium to the inside surface of the sphere. As late as 1945 the Moseley model guided other efforts to build experimental batteries generating electricity from the emissions of radioactive elements.

Electromechanical conversion

Main article: Radioisotope piezoelectric generator

Electromechanical atomic batteries use the buildup of charge between two plates to pull one bendable plate towards the other, until the two plates touch, discharge, equalizing the electrostatic buildup, and spring back. The mechanical motion produced can be used to produce electricity through flexing of a

piezoelectric material or through a linear generator. Milliwatts of power are produced in pulses depending on the charge rate, in some cases multiple times per second (35 Hz).[9]

Radiovoltaic conversion

A radiovoltaic (RV) device converts the energy of ionizing radiation directly into electricity using a

photovoltaic cell
. Depending on the type of radiation targeted, these devices are called alphavoltaic (AV, αV), betavoltaic (BV, βV) and/or gammavoltaic (GV, γV). Betavoltaics have traditionally received the most attention since (low-energy) beta emitters cause the least amount of radiative damage, thus allowing a longer operating life and less shielding. Interest in alphavoltaic and (more recently) gammavoltaic devices is driven by their potential higher efficiency.

Alphavoltaic conversion

Alphavoltaic devices use a semiconductor junction to produce electrical energy from energetic alpha particles.[10][11]

Betavoltaic conversion

Main article: Betavoltaic device

Betavoltaic devices use a semiconductor junction to produce electrical energy from energetic beta particles (electrons). A commonly used source is the hydrogen isotope tritium.

Betavoltaic devices are particularly well-suited to low-power electrical applications where long life of the energy source is needed, such as implantable medical devices or military and space applications.[12]

The Chinese startup Betavolt claimed in January 2024 to have a miniature device in the pilot testing stage.[13] It is allegedly generating 100 microwatts of power and a voltage of 3V and has a lifetime of 50 years without any need for charging or maintenance.[13] Betavolt claims it to be the first such miniaturised device ever developed.[13] It gains its energy from the isotope

nickel-63 located in a module the size of a very small coin.[14]
As it's consumed, the nickel-63 decays into stable, non-radioactive isotopes of copper, which pose no environmental threat.[14] It contains a thin wafer of nickel-63 providing beta particle electrons sandwiched between two thin crystallographic diamond semiconductor layers.[15][16]

Gammavoltaic conversion

Gammavoltaic devices use a semiconductor junction to produce electrical energy from energetic

gamma particles (high-energy photons). They have only been considered in the 2010s[17][18][19][20] but were proposed as early as 1981.[21]

A gammavoltaic effect has been reported in perovskite solar cells.[17] Another patented design involves scattering of the gamma particle until its energy has decreased enough to be absorbed in a conventional photovoltaic cell.[18] Gammavoltaic designs using diamond and Schottky diodes are also being investigated.[19][20]

Radiophotovoltaic (optoelectric) conversion

Main article: Optoelectric nuclear battery

In a radiophotovoltaic (RPV) device the energy conversion is indirect: the emitted particles are first converted into light using a radioluminescent material (a scintillator or phosphor), and the light is then converted into electricity using a photovoltaic cell. Depending on the type of particle targeted, the conversion type can be more precisely specified as alphaphotovoltaic (APV or α-PV),[22] betaphotovoltaic (BPV or β-PV)[23] or gammaphotovoltaic (GPV or γ-PV).[24]

Radiophotovoltaic conversion can be combined with radiovoltaic conversion to increase the conversion efficiency.[25]

Pacemakers

Medtronic and Alcatel developed a

Betavoltaic batteries are also being considered as long-lasting power sources for lead-free pacemakers.[30]

Radioisotopes used

Atomic batteries use radioisotopes that produce low energy beta particles or sometimes alpha particles of varying energies. Low energy beta particles are needed to prevent the production of high energy penetrating

fission product easily extracted from spent nuclear fuel
.

Plutonium-238 must be deliberately produced via neutron irradiation of Neptunium-237 but it can be easily converted into a stable plutonium oxide ceramic. Strontium-90 is easily extracted from spent nuclear fuel but must be converted into the

isotopes of Caesium
which reduce power density further.

Micro-batteries

In the field of microelectromechanical systems (

MEMS
devices to communicate with one another wirelessly.

These micro-batteries are very light and deliver enough energy to function as power supply for use in MEMS devices and further for supply for nanodevices.[32]

The radiation energy released is transformed into electric energy, which is restricted to the area of the device that contains the processor and the micro-battery that supplies it with energy.[33]: 180–181 

See also

References

  1. ^ "A nuclear battery the size and thickness of a penny". Gizmag, 9 October 2009.
  2. ^ "Tiny 'nuclear batteries' unveiled". BBC News, Thursday, 8 October 2009.
  3. ^ "NanoTritium™ Battery Technology". City Labs. Retrieved 25 May 2023.
  4. ^ "Atomic Battery Converts Radioactivity Directly Into Electricity". Popular Mechanics, April 1954, p. 87.
  5. ^ "Thermoelectric Generators". electronicbus.com. Archived from the original on 10 January 2016. Retrieved 23 February 2015.
  6. OSTI 6377296
    .
  7. OSTI 168371
    .
  8. ^ The ASRG Cancellation in Context Future Planetary Exploration
  9. S2CID 18891519. Archived from the original
    (PDF) on 21 June 2007.
  10. ^ NASA Glenn Research Center, Alpha- and Beta-voltaics Archived 18 October 2011 at the Wayback Machine (accessed 4 October 2011)
  11. ^ Sheila G. Bailey, David M. Wilt, Ryne P. Raffaelle, and Stephanie L. Castro, Alpha-Voltaic Power Source Designs Investigated Archived 16 July 2010 at the Wayback Machine, Research and Technology 2005, NASA TM-2006-214016, (accessed 4 October 2011)
  12. ^ "Tritium Batteries as a Source of Nuclear Power". City Labs. Retrieved 25 May 2023.
  13. ^ a b c Anthony Cuthbertson (12 January 2024). "Nuclear battery produces power for 50 years without needing to charge". The Independent. Retrieved 14 January 2024.
  14. ^ a b Mark Tyson (13 January 2024). "Chinese-developed nuclear battery has a 50-year lifespan — Betavolt BV100 built with Nickel-63 isotope and diamond semiconductor material". Tom's Hardware. Retrieved 17 January 2024.
  15. ^ "Betavolt says its diamond nuclear battery can power devices for 50 years". David Szondy for New Atlas, 16 January 2024. Accessed 17 January 2024.
  16. ^ "贝塔伏特公司成功研制民用原子能电池" ('Betavolt successfully develops atomic energy battery for civilian use'), on Betavolt website (in Chinese). Accessed 17 January 2024.
  17. ^ a b Hiroshi Segawa; Ludmila Cojocaru; Satoshi Uchida (7 November 2016). "Gammavoltaic Property of Perovskite Solar Cell - Toward the Novel Nuclear Power Generation". Proceedings of International Conference Asia-Pacific Hybrid and Organic Photovoltaics. Retrieved 1 September 2020.
  18. ^ a b 20180350482, Ryan, Michael Doyle, "Gamma Voltaic Cell", issued 2018-12-06 
  19. ^ a b MacKenzie, Gordon (October 2017). "A Diamond Gammavoltaic Cell". UK Research and Innovation.
  20. ^ a b Mackenzie, Robbie (19 June 2020). "Diamond Gammavoltaic Cells for Biasless Gamma Dosimetry". South West Nuclear Hub. Retrieved 1 September 2020.
  21. ^ "Popular Science". January 1981.
  22. S2CID 141390756
    .
  23. S2CID 139545450
    .
  24. S2CID 98136174
    .
  25. S2CID 117568424
    .
  26. ^ "MedTech Memoirs: The Plutonium-Powered Pacemaker".
  27. ^ "Nuclear pacemaker still energized after 34 years".
  28. ^ R L Shoup."Nuclear-Powered Cardiac Pacemakers".
  29. ^ Crystal Phend."Extra Battery Life Not Always a Plus for Nuclear-Powered Pacemaker".
  30. ^ "Pacemaker Batteries for Leadless Pacemakers". City Labs. Retrieved 25 May 2023.
  31. doi:10.1063/1.4802359
    .
  32. ISBN 978-2-7462-1516-0
    .
  33. ISBN 978-1-84704-002-2
    . radioactive nuclei releases electrons that shoot the negative pole of the battery

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Atomic_battery&oldid=1198234638"