View source for Physics:Diamond battery

{{Short description|Proposed nuclear battery concept}}
'''Diamond battery''' is the name of a nuclear battery concept proposed by the [[Organization:University of Bristol|University of Bristol]] Cabot Institute during its annual lecture<ref>{{cite web|title=Annual Lecture 2016: Ideas to change the world|url=http://www.bristol.ac.uk/cabot/events/2016/annual-lecture-2016.html|publisher=University of Bristol|access-date=2016-12-01|archive-date=2020-10-29|archive-url=https://web.archive.org/web/20201029173015/http://www.bristol.ac.uk/cabot/events/2016/annual-lecture-2016.html|url-status=dead}}</ref> held on 25 November 2016 at the Wills Memorial Building. This battery is proposed to run on the radioactivity of waste [[Chemistry:Graphite|graphite]] blocks (previously used as [[Physics:Neutron moderator|neutron moderator]] material in [[Engineering:Graphite-moderated reactor|graphite-moderated reactor]]s) and would generate small amounts of electricity for thousands of years.

The battery is a betavoltaic cell using [[Physics:Carbon-14|carbon-14]] (<sup>14</sup>C) in the form of [[Physics:Diamond-like carbon|diamond-like carbon]] (DLC) as the beta radiation source, and additional normal-carbon DLC to make the necessary semiconductor junction and encapsulate the carbon-14.<ref name="seeker">{{cite web|title=Nuclear Waste and Diamonds Make Batteries That Last 5,000 Years|url=http://www.seeker.com/nuclear-waste-and-diamonds-make-batteries-that-last-5000-years-2120412155.html | website=Seeker|date = 30 November 2016}}</ref>

== Prototypes ==
Currently, no known prototype uses <sup>14</sup>C as its source. There are, however, some prototypes that use [[Physics:Nickel-63|nickel-63]] (<sup>63</sup>Ni) as their source with diamond non-electrolytes/semiconductors for energy conversion, which are seen as a stepping stone to a possible <sup>14</sup>C diamond battery prototype.

=== University of Bristol prototype ===
In 2016, researchers from the University of Bristol claimed to have constructed one of those <sup>63</sup>Ni prototypes.<ref name="inhabitat">{{cite web|title=Scientists turn nuclear waste into diamond batteries that last virtually forever|last1=DiStaslo|first1=Cat|url=http://inhabitat.com/new-man-made-diamonds-turn-nuclear-waste-into-long-lasting-batteries/|publisher=Inhabitat|date = 2 December 2016}}</ref><ref name="electronics-weekly">{{cite web|title = Diamond nuclear battery could generate 100&nbsp;μW for 5,000 years|publisher = Electronics Weekly | date = 2 December 2016 | url = http://www.electronicsweekly.com/news/research-news/diamond-nuclear-battery-generate-100%CE%BCw-5000-years-2016-12/}}</ref>

From their Frequently Asked Questions (FAQ document<ref>{{Cite web |url=https://www.bristol.ac.uk/media-library/sites/cabot-institute-2018/documents/Diamond_battery_FAQs_Nov_2016.pdf |title=Diamond Battery FAQs |access-date=2022-11-21 |archive-date=2022-11-20 | publisher=University of Bristol |archive-url=https://web.archive.org/web/20221120231856/https://www.bristol.ac.uk/media-library/sites/cabot-institute-2018/documents/Diamond_battery_FAQs_Nov_2016.pdf |url-status=live }}</ref>), the estimated power of a small C-14 cell is 15&nbsp;J/day for thousands of years. (For reference, a AA battery of the same size has about 10&nbsp;kJ total, which is equivalent to 15&nbsp;J/day for just 2 years.) They note it is not possible to directly replace a AA battery with this technology, because a AA battery can produce bursts of much higher power as well. Instead, the diamond battery is aimed at applications where a low discharge rate over a long period of time is required, such as space exploration, medical devices, seabed communications, microelectronics, etc.

=== Moscow Institute of Physics and Technology prototype ===

In 2018, researchers from the [[Organization:Moscow Institute of Physics and Technology|Moscow Institute of Physics and Technology]] (MIPT), the Technological Institute for Superhard and Novel Carbon Materials (TISNCM), and the National University of Science and Technology (MISIS) announced a prototype using 2-micron thick layers of <sup>63</sup>Ni foil sandwiched between 200 10-micron diamond converters. It produced a power output of about 1 μW at for [[Physics:Power density|power density]] of 10 μW/cm<sup>3</sup>. At those values, its energy density would be approximately 3.3 Wh/g over its 100-year [[Physics:Half-life|half-life]], about 10 times that of conventional [[Chemistry:Electrochemical cell|electrochemical batteries]].<ref name="mipt1">{{Cite web|url=https://mipt.ru/english/news/prototype_nuclear_battery_packs_10_times_more_power|title=Prototype nuclear battery packs 10 times more power|website=mipt.ru}}</ref> This research was published in April 2018 in the ''[[Physics:Diamond and Related Materials|Diamond and Related Materials]]'' journal.<ref name="scidi1">{{cite journal|title = High power density nuclear battery prototype based on diamond Schottky diodes| date = April 2018 |doi = 10.1016/j.diamond.2018.03.006 |last1 = Bormashov |first1 = V.S. |last2 = Troschiev |first2 = S.Yu. |last3 = Tarelkin |first3 = S.A. |last4 = Volkov |first4 = A.P. |last5 = Teteruk |first5 = D.V. |last6 = Golovanov |first6 = A.V. |last7 = Kuznetsov |first7 = M.S. |last8 = Kornilov |first8 = N.V. |last9 = Terentiev |first9 = S.A. |last10 = Blank |first10 = V.D. |journal = Diamond and Related Materials |volume = 84 |pages = 41–47 |bibcode = 2018DRM....84...41B |doi-access = free }}</ref>

== Carbon-14 ==
Researchers are trying to improve the efficiency and are focusing on use of radioactive [[Physics:Isotopes of carbon|<sup>14</sup>C]], which is a minor contributor to the radioactivity of [[Physics:Radioactive waste|nuclear waste]].<ref name="inhabitat"/>

<sup>14</sup>C undergoes [[Physics:Beta decay|beta decay]], in which it emits a low-energy [[Physics:Beta particle|beta particle]] to become [[Physics:Nitrogen-14|Nitrogen-14]], which is [[Physics:Stable isotope|stable]] (not radioactive).<ref>{{cite web|title=Nuclear Reactions/Beta Decay|url=http://chem.libretexts.org/Core/Physical_and_Theoretical_Chemistry/Nuclear_Chemistry/Nuclear_Reactions|website=libretexts.org|date=2013-11-26}}</ref>

:{{nuclide|carbon|14}} → {{nuclide|nitrogen|14}} + {{physics particle|β|BL=−1|TL=0}}

These beta particles, having an average energy of 50 keV, undergo inelastic collisions with other carbon atoms, thus creating electron-hole pairs which then contribute to an [[Physics:Electric current|electric current]]. This can be restated in terms of [[Physics:Electronic band structure|band theory]] by saying that due to the high energy of the beta particles, electrons in the carbon valence band ''jump to'' its conduction band, leaving behind [[Physics:Electron hole|holes]] in the valence band where electrons were earlier present.<ref>{{cite web | title=Flash Physics: Nuclear diamond battery, M G K Menon dies, four new elements named | url = http://physicsworld.com/cws/article/news/2016/nov/30/flash-physics-nuclear-diamond-battery-m-g-k-menon-dies-four-new-elements-named | publisher = Physics World | date = 30 November 2016}}</ref><ref name="electronics-weekly"/>

==Proposed manufacturing==
In [[Engineering:Graphite-moderated reactor|graphite-moderated reactor]]s, fissile [[Chemistry:Uranium|uranium]] rods are placed inside [[Chemistry:Graphite|graphite]] blocks. These blocks act as a [[Physics:Neutron moderator|neutron moderator]] whose purpose is to slow down fast-moving neutrons so that [[Physics:Nuclear chain reaction|nuclear chain reaction]]s can occur with [[Physics:Neutron temperature#Thermal|thermal neutrons]].<ref>{{cite web|title='Diamond-age' of power generation as nuclear batteries developed|url=https://www.youtube.com/watch?v=b6ME88nMnYE|website=Youtube|publisher=University of Bristol}}</ref> During their use, some of the non-radioactive [[Physics:Carbon-12|carbon-12]] and [[Physics:Carbon-13|carbon-13]] [[Physics:Isotopes of carbon|isotopes]] in graphite get converted into radioactive <sup>14</sup>C by [[Physics:Neutron capture|capturing neutrons]].<ref>{{cite web|title=Radioactive Diamond Batteries: Making Good Use Of Nuclear Waste| url=https://www.forbes.com/sites/jamesconca/2016/12/09/radioactive-diamond-batteries-making-good-use-of-nuclear-waste/#1e4c95016bac|website=Forbes | date = 9 December 2016}}</ref> When the graphite blocks are removed during station decommissioning, their [[Physics:Induced radioactivity|induced radioactivity]] qualifies them as low-level waste requiring safe disposal.

Researchers at the University of Bristol demonstrated that a large amount of the radioactive <sup>14</sup>C was concentrated on the inner walls of the graphite blocks. Due to this, they propose that much of it can be effectively removed from the blocks. This can be done by heating them to the [[Sublimation (phase transition)|sublimation]] point of {{convert|3915|K|°C °F|abbr=on}} which will release the carbon in gaseous form. After this, blocks will be less radioactive and possibly easier to dispose of with most of the radioactive <sup>14</sup>C having been extracted.<ref name="bristol-pr">{{cite web | title='Diamond-age' of power generation as nuclear batteries developed | url=http://www.bristol.ac.uk/news/2016/november/diamond-power.html | publisher = [[Organization:University of Bristol|University of Bristol]] | date = 25 November 2016}}</ref>

Those researchers propose that this <sup>14</sup>C gas could be collected and used to produce man-made diamonds by a process known as [[Chemistry:Chemical vapor deposition|chemical vapor deposition]] using low pressure and elevated temperature, noting that this diamond would be a thin sheet and not of the stereotypical [[Chemistry:Diamond cut|diamond cut]]. The resulting diamond made of radioactive <sup>14</sup>C would still produce beta radiation which researchers claim would allow it to be used as a betavoltaic source. Researchers also claim this diamond would be sandwiched between non-radioactive man-made diamonds made from <sup>12</sup>C which would block radiation from the source and would also be used for energy conversion as a [[Chemistry:Material properties of diamond#Electrical properties|diamond semiconductor]] instead of conventional [[Physics:List of semiconductor materials|silicon semiconductors]].<ref name="bristol-pr"/>

== Proposed applications ==
Due to its very low [[Physics:Power density|power density]], conversion efficiency and high cost, a <sup>14</sup>C betavoltaic device is very similar to other existing [[Physics:Betavoltaic device|betavoltaic device]]s which are suited to niche applications needing very little power (microwatts) for several years in situations where conventional batteries cannot be replaced or recharged using conventional [[Engineering:Energy harvesting|energy harvesting]] techniques.<ref>{{Cite web |url=http://www.bristol.ac.uk/news/2016/november/diamond-power.html |title=Bristol university Press release issued: 25 November 2016 |access-date=3 December 2016 |archive-date=20 November 2022 |archive-url=https://web.archive.org/web/20221120231903/http://www.bristol.ac.uk/news/2016/november/diamond-power.html |url-status=live }}</ref><ref>{{Cite web |url=http://www.bristol.ac.uk/engineering/research/csn/projects/aspire/ |title=Bristol University interdisciplinary Aspire project, 2017 |access-date=2020-10-02 |archive-date=2021-05-29 |archive-url=https://web.archive.org/web/20210529032357/http://www.bristol.ac.uk/engineering/research/csn/projects/aspire/ |url-status=dead }}</ref><ref>{{cite web |title=Tritium Batteries as a Source of Nuclear Power |url=https://citylabs.net/applications/ |website=City Labs |access-date=25 May 2023}}</ref> Due to its longer [[Physics:Half-life|half-life]], <sup>14</sup>C betavoltaics may have an advantage in service life when compared to other betavoltaics using [[Physics:Tritium|tritium]] or [[Physics:Isotopes of nickel|nickel]]. However, this will likely come at the cost of further reduced power density.

===Commercialization===
In September 2020, Morgan Boardman, an Industrial Fellow and Strategic Advisory Consultant with the Aspire Diamond Group at the South West Nuclear Hub of the University of Bristol, was appointed CEO of a new company called ''Arkenlight'', which was created explicitly to commercialize their diamond battery technology and possibly other nuclear radiation devices under research or development at Bristol University.<ref>{{Cite web |url=https://newatlas.com/energy/arkenlight-nuclear-diamond-batteries/ |title=New Atlas (formerly Gizmag) interview with Dr Boardman |date=30 September 2020 |access-date=2020-10-02 |archive-date=2022-11-20 |archive-url=https://web.archive.org/web/20221120231856/https://newatlas.com/energy/arkenlight-nuclear-diamond-batteries/ |url-status=live }}</ref>

== References ==
{{Reflist}}

== External links ==
{{Library resources box}}

* [https://www.youtube.com/watch?v=hvI5kZnq5qY The speech that proposed the battery]
* [https://www.snopes.com/fact-check/radioactive-diamond-batteries-real-thing Are Radioactive ‘Diamond Batteries’ a Real Thing?]

[[Category:Radioactivity]]
[[Category:Diamond|Battery]]

{{Sourceattribution|Diamond battery}}