Editing Vanadium (section)

== Applications ==
[[File:Knarre.jpg|thumb|upright|right|Tool made from vanadium steel]]

=== Alloys ===
Approximately 85% of the vanadium produced is used as [[ferrovanadium]] or as a [[steel]] additive.<ref name="Moskalyk" /> The considerable increase of strength in steel containing small amounts of vanadium was discovered in the early 20th century. Vanadium forms stable nitrides and carbides, resulting in a significant increase in the strength of steel.<ref name="Chandler">{{cite book |last=Chandler |first=Harry |url=https://books.google.com/books?id=arupok8PTBEC |title=Metallurgy for the Non-metallurgist |date=1998 |publisher=ASM International |isbn=978-0-87170-652-2 |pages=6–7}}</ref> From that time on, vanadium steel was used for applications in [[axle]]s, bicycle frames, [[crankshaft]]s, gears, and other critical components. There are two groups of vanadium steel alloys. Vanadium high-carbon steel alloys contain 0.15–0.25% vanadium, and [[High-speed steel|high-speed tool steels]] (HSS) have a vanadium content of 1–5%. For high-speed tool steels, a hardness above [[Rockwell hardness|HRC]] 60 can be achieved. HSS steel is used in [[surgical instrument]]s and [[tool]]s.<ref>{{cite book |last=Davis |first=Joseph R. |url=https://books.google.com/books?id=Kws7x68r_aUC&pg=PA11 |title=Tool Materials: Tool Materials |date=1995 |publisher=ASM International |isbn=978-0-87170-545-7}}</ref> [[Powder metallurgy|Powder-metallurgic]] alloys contain up to 18% percent vanadium. The high content of vanadium carbides in those alloys increases wear resistance significantly. One application for those alloys is tools and knives.<ref>{{cite book |author1=Oleg D. Neikov |url=https://books.google.com/books?id=6aP3te2hGuQC&pg=PA490 |title=Handbook of Non-Ferrous Metal Powders: Technologies and Applications |last2=Naboychenko |first2=Stanislav |last3=Mourachova |first3=Irina |author4=Victor G. Gopienko |author5=Irina V. Frishberg |author6=Dina V. Lotsko |date=2009-02-24 |isbn=978-0-08-055940-7 |page=490 | publisher=Elsevier |access-date=17 October 2013}}</ref><!--http://www.wujii.com.tw/PDF/CPM%2015V.pdf-->

Vanadium stabilizes the beta form of titanium and increases the strength and temperature stability of titanium. Mixed with [[aluminium]] in [[titanium]] alloys, it is used in [[jet engine]]s, high-speed airframes and [[dental implant]]s. The most common alloy for seamless tubing is [[titanium alloy#Grades of titanium|Titanium 3/2.5]] containing 2.5% vanadium, the titanium alloy of choice in the aerospace, defense, and bicycle industries.<ref>{{cite web |title=Technical Supplement: Titanium |url=http://www.sevencycles.com/buildingbike/techsupplement/ti.php |url-status=dead |archive-url=https://web.archive.org/web/20161103173648/http://www.sevencycles.com/buildingbike/techsupplement/ti.php |archive-date=3 November 2016 |access-date=1 November 2016 |website=Seven Cycles}}</ref> Another common alloy, primarily produced in sheets, is [[Titanium 6AL-4V]], a titanium alloy with 6% aluminium and 4% vanadium.<ref>{{cite book |last1=Zwicker |first1=Ulrich |title=Titan und Titanlegierungen |year=1974 |isbn=978-3-642-80588-2 |pages=4–29 |chapter=Herstellung des Metalls |doi=10.1007/978-3-642-80587-5_2}}</ref>

Several vanadium alloys show [[Superconductivity|superconducting]] behavior. The first [[A15 phase]] superconductor was a vanadium compound, V<sub>3</sub>Si, which was discovered in 1952.<ref>{{cite journal |last1=Hardy |first1=George F. |last2=Hulm |first2=John K. |date=15 February 1953 |title=Superconducting Silicides and Germanides |journal=Physical Review |volume=89 |issue=4 |pages=884 |bibcode=1953PhRv...89Q.884H |doi=10.1103/PhysRev.89.884}}</ref> [[Vanadium-gallium]] tape is used in [[superconductivity|superconducting]] magnets (17.5 [[tesla (unit)|teslas]] or 175,000 [[gauss (unit)|gauss]]). The structure of the superconducting A15 phase of V<sub>3</sub>Ga is similar to that of the more common [[niobium-tin|Nb<sub>3</sub>Sn]] and [[niobium-titanium|Nb<sub>3</sub>Ti]].<ref>{{cite journal |last1=Markiewicz |first1=W. |last2=Mains |first2=E. |last3=Vankeuren |first3=R. |last4=Wilcox |first4=R. |last5=Rosner |first5=C. |last6=Inoue |first6=H. |last7=Hayashi |first7=C. |last8=Tachikawa |first8=K. |date=January 1977 |title=A 17.5 Tesla superconducting concentric {{chem|Nb|3|Sn}} and {{chem|V|3|Ga}} magnet system |journal=IEEE Transactions on Magnetics |volume=13 |issue=1 |pages=35–37 |doi=10.1109/TMAG.1977.1059431}}</ref>

It has been found that a small amount, 40 to 270&nbsp;ppm, of vanadium in [[Wootz steel]] significantly improved the strength of the product, and gave it the distinctive patterning. The source of the vanadium in the original Wootz steel ingots remains unknown.<ref>{{cite journal |last1=Verhoeven |first1=J. D. |last2=Pendray |first2=A. H. |last3=Dauksch |first3=W. E. |date=September 1998 |title=The key role of impurities in ancient damascus steel blades |journal=JOM |volume=50 |issue=9 |pages=58–64 |bibcode=1998JOM....50i..58V |doi=10.1007/s11837-998-0419-y |s2cid=135854276}}</ref>

Vanadium can be used as a substitute for molybdenum in armor steel, though the alloy produced is far more brittle and prone to [[spalling]] on non-penetrating impacts.<ref>{{cite journal |last=Rohrmann |first=B. |year=1985 |title=Vanadium in South Africa (Metal Review Series no. 2) |journal=Journal of the Southern African Institute of Mining and Metallurgy |volume=85 |issue=5 |pages=141–150 |hdl=10520/AJA0038223X_1959}}</ref> The Third Reich was one of the most prominent users of such alloys, in armored vehicles like [[Tiger II]] or [[Jagdtiger]].<ref>{{cite journal |last=Overy |first=R. J. |year=1973 |title=Transportation and Rearmament in the Third Reich |journal=The Historical Journal |volume=16 |issue=2 |pages=389–409 |doi=10.1017/s0018246x00005926 |s2cid=153437214}}</ref>

=== Catalysts ===
[[File:Vanadium pentoxide powder.jpg|thumb|upright|[[Vanadium(V) oxide]] is a catalyst in the [[contact process]] for producing sulfuric acid.]]

Vanadium compounds are used extensively as catalysts;<ref>{{cite journal |last1=Langeslay |first1=Ryan R. |last2=Kaphan |first2=David M. |last3=Marshall |first3=Christopher L. |last4=Stair |first4=Peter C. |last5=Sattelberger |first5=Alfred P. |last6=Delferro |first6=Massimiliano |date=8 October 2018 |title=Catalytic Applications of Vanadium: A Mechanistic Perspective |journal=Chemical Reviews |volume=119 |issue=4 |pages=2128–2191 |doi=10.1021/acs.chemrev.8b00245 |osti=1509906 |pmid=30296048 |s2cid=52943647}}</ref> [[vanadium(V) oxide|Vanadium pentoxide]] V<sub>2</sub>O<sub>5</sub>, is used as a [[catalyst]] in manufacturing sulfuric acid by the [[contact process]]<ref>{{cite journal |last1=Eriksen |first1=K.M. |last2=Karydis |first2=D.A. |last3=Boghosian |first3=S. |last4=Fehrmann |first4=R. |date=August 1995 |title=Deactivation and Compound Formation in Sulfuric-Acid Catalysts and Model Systems |journal=Journal of Catalysis |volume=155 |issue=1 |pages=32–42 |doi=10.1006/jcat.1995.1185}}</ref> In this process [[sulfur dioxide]] ({{chem|SO|2}}) is oxidized to the [[sulfur trioxide|trioxide]] ({{chem|SO|3}}):<ref name="HollemanAF" /> In this [[redox reaction]], sulfur is oxidized from +4 to +6, and vanadium is reduced from +5 to +4:
:V<sub>2</sub>O<sub>5</sub> + SO<sub>2</sub> → 2 VO<sub>2</sub> + SO<sub>3</sub>

The catalyst is regenerated by oxidation with air:
:4 VO<sub>2</sub> + O<sub>2</sub> → 2 V<sub>2</sub>O<sub>5</sub>
Similar oxidations are used in the production of [[maleic anhydride]]:
:C<sub>4</sub>H<sub>10</sub>  + 3.5 O<sub>2</sub>  →   C<sub>4</sub>H<sub>2</sub>O<sub>3</sub>  +  4 H<sub>2</sub>O
[[Phthalic anhydride]] and several other bulk organic compounds are produced similarly. These [[green chemistry]] processes convert inexpensive feedstocks to highly functionalized, versatile intermediates.<ref name="Ullmann">{{Ullmann|doi=10.1002/14356007.a27_367|title=Vanadium and Vanadium Compounds|year=2000|last1=Bauer|first1=Günter|last2=Güther|first2=Volker|last3=Hess|first3=Hans|last4=Otto|first4=Andreas|last5=Roidl|first5=Oskar|last6=Roller|first6=Heinz|last7=Sattelberger|first7=Siegfried|isbn=3-527-30673-0}}</ref><ref>{{cite journal |last1=Abon |first1=Michel |last2=Volta |first2=Jean-Claude |date=September 1997 |title=Vanadium phosphorus oxides for n-butane oxidation to maleic anhydride |journal=Applied Catalysis A: General |volume=157 |issue=1–2 |pages=173–193 |doi=10.1016/S0926-860X(97)00016-1|bibcode=1997AppCA.157..173A }}</ref>

Vanadium is an important component of mixed metal oxide catalysts used in the oxidation of propane and propylene to [[acrolein]], acrylic acid or the ammoxidation of propylene to [[acrylonitrile]].<ref>{{cite book |title=Metal Oxides, Chemistry and Applications |date=2006 |publisher=CRC Press |isbn=978-0-8247-2371-2 |editor1-last=Fierro |editor1-first=J. G. L. |pages=415–455}}</ref>

=== Other uses ===
The [[vanadium redox battery]], a type of [[flow battery]], is an electrochemical cell consisting of aqueous vanadium ions in different oxidation states.<ref>{{cite journal |last1=Joerissen |first1=Ludwig |last2=Garche |first2=Juergen |last3=Fabjan |first3=Ch. |last4=Tomazic |first4=G. |date=March 2004 |title=Possible use of vanadium redox-flow batteries for energy storage in small grids and stand-alone photovoltaic systems |journal=Journal of Power Sources |volume=127 |issue=1–2 |pages=98–104 |bibcode=2004JPS...127...98J |doi=10.1016/j.jpowsour.2003.09.066}}</ref><ref name="RychcikSkyllas-Kazacos1988">{{cite journal |last1=Rychcik |first1=M. |last2=Skyllas-Kazacos |first2=M. |date=January 1988 |title=Characteristics of a new all-vanadium redox flow battery |journal=Journal of Power Sources |volume=22 |issue=1 |pages=59–67 |bibcode=1988JPS....22...59R |doi=10.1016/0378-7753(88)80005-3}}</ref> Batteries of this type were first proposed in the 1930s and developed commercially from the 1980s onwards. Cells use +5 and +2 formal oxidization state ions. Vanadium redox batteries are used commercially for [[grid energy storage]].<ref>{{Cite journal |last1=Li |first1=Liyu |last2=Kim |first2=Soowhan |last3=Wang |first3=Wei |last4=Vijayakumar |first4=M. |last5=Nie |first5=Zimin |last6=Chen |first6=Baowei |last7=Zhang |first7=Jianlu |last8=Xia |first8=Guanguang |last9=Hu |first9=Jianzhi |last10=Graff |first10=Gordon |last11=Liu |first11=Jun |last12=Yang |first12=Zhenguo |date=May 2011 |title=A Stable Vanadium Redox-Flow Battery with High Energy Density for Large-Scale Energy Storage |journal=Advanced Energy Materials |volume=1 |issue=3 |pages=394–400 |doi=10.1002/aenm.201100008 |bibcode=2011AdEnM...1..394L |s2cid=33277301}}</ref>

[[Vanadate]] can be used for protecting steel against rust and corrosion by [[conversion coating]].<ref>{{cite journal |last1=Guan |first1=H. |last2=Buchheit |first2=R. G. |date=1 March 2004 |title=Corrosion Protection of Aluminum Alloy 2024-T3 by Vanadate Conversion Coatings |journal=Corrosion |volume=60 |issue=3 |pages=284–296 |doi=10.5006/1.3287733}}</ref> Vanadium foil is used in [[cladding (metalworking)|cladding]] titanium to steel because it is compatible with both iron and titanium.<ref>{{cite journal |last1=Lositskii |first1=N. T. |last2=Grigor'ev |first2=A. A. |last3=Khitrova |first3=G. V. |date=December 1966 |title=Welding of chemical equipment made from two-layer sheet with titanium protective layer (review of foreign literature) |journal=Chemical and Petroleum Engineering |volume=2 |issue=12 |pages=854–856 |doi=10.1007/BF01146317 |bibcode=1966CPE.....2..854L |s2cid=108903737}}</ref> The moderate [[neutron capture|thermal neutron-capture cross-section]] and the short half-life of the isotopes produced by neutron capture makes vanadium a suitable material for the inner structure of a [[fusion reactor]].<ref>{{cite journal |last1=Matsui |first1=H. |last2=Fukumoto |first2=K. |last3=Smith |first3=D.L. |last4=Chung |first4=Hee M. |last5=van Witzenburg |first5=W. |last6=Votinov |first6=S.N. |date=October 1996 |title=Status of vanadium alloys for fusion reactors |url=https://zenodo.org/record/1259631 |url-status=live |journal=Journal of Nuclear Materials |volume=233-237 |pages=92–99 |bibcode=1996JNuM..233...92M |doi=10.1016/S0022-3115(96)00331-5 |archive-url=https://web.archive.org/web/20210215013608/https://zenodo.org/record/1259631 |archive-date=15 February 2021 |access-date=10 August 2018}}</ref><ref>{{cite web |title=Vanadium Data Sheet |url=http://www.wahchang.com/pages/products/data/pdf/Vanadium.pdf |archive-url=https://web.archive.org/web/20090225153938/http://www.wahchang.com/pages/products/data/pdf/Vanadium.pdf |archive-date=25 February 2009 |access-date=16 January 2009 |publisher=[[ATI Wah Chang]]}}</ref>

Vanadium can be added in small quantities <&nbsp;5% to [[Lithium iron phosphate battery|LFP battery]] cathodes to increase ionic conductivity.<ref>{{Cite patent|number=US7842420B2|title=Electrode material with enhanced ionic transport properties|gdate=2010-11-30|invent1=Wixom|invent2=Xu|inventor1-first=Michael R.|inventor2-first=Chuanjing|url=https://patents.google.com/patent/US7842420B2/en?oq=7842420}}</ref>

==== Proposed ====
[[Lithium vanadium oxide]] has been proposed for use as a high-energy-density anode for [[Lithium-ion battery|lithium-ion batteries]], at 745&nbsp;Wh/L when paired with a [[lithium cobalt oxide]] cathode.<ref>{{cite web |last=Kariatsumari |first=Koji |date=February 2008 |title=Li-Ion Rechargeable Batteries Made Safer |url=http://techon.nikkeibp.co.jp/article/HONSHI/20080129/146549/ |url-status=dead |archive-url=https://web.archive.org/web/20110912020554/http://techon.nikkeibp.co.jp/article/HONSHI/20080129/146549/ |archive-date=12 September 2011 |access-date=10 December 2008 |publisher=Nikkei Business Publications, Inc.}}</ref> [[Vanadium phosphate]]s have been proposed as the cathode in the [[lithium vanadium phosphate battery]], another type of lithium-ion battery.<ref>{{citation |last1=Saıdi |first1=M.Y. |title=Performance characteristics of lithium vanadium phosphate as a cathode material for lithium-ion batteries |date=1 June 2003 |journal=Journal of Power Sources |volume=119–121 |pages=266–272 |bibcode=2003JPS...119..266S |doi=10.1016/S0378-7753(03)00245-3 |last2=Barker |first2=J. |last3=Huang |first3=H. |last4=Swoyer |first4=J.L. |last5=Adamson |first5=G.}} Selected papers presented at the 11th International Meeting on Lithium Batteries</ref>