{ "spore": "profile", "id": "vanadium-pentoxide", "spore_version": "0.2", "family": "oxide-ceramics", "name": "Vanadium pentoxide", "abbreviation": "V2O5", "role": "catalyst, flow-battery feedstock and infrared-sensor film material", "category": "ceramics", "type": "oxides", "summary": "Vanadium pentoxide (V2O5) is a yellow-to-red oxide of vanadium with the vanadium in its +5 state. It melts at 690 °C on the ICSC safety card (681 °C in PubChem's database record) and decomposes at 1750 °C. Its industrial role is as the oxygen-transfer catalyst for sulfuric acid and maleic anhydride, and as a starting point for vanadium metal and ferrovanadium. In laboratory tests, sputtered V2O5 and vanadium multilayers gave high temperature coefficients of resistance for infrared microbolometers, and the powder is toxic: the ECHA notifications in PubChem carry the Danger signal word.\n", "best_for": "Lab-scale thermometer films for uncooled infrared sensors, and as a vanadium source for flow batteries and catalysts", "weakest_at": "Toxicity. Fatal if inhaled (H330) and toxic if swallowed (H301) in the aggregated EU classification, with an occupational limit of 0.05 mg/m3 as V", "identity": { "formula": "V2O5", "cas": "1314-62-1", "crystal_system": "orthorhombic", "space_group": "Pmmn", "designations": [], "source": "icsc-0596", "where": "Header, CAS #; Physical and Chemical Information, Formula. Crystal system and space group: Wikipedia infobox (wikipedia-v2o5)" }, "tags": { "environments": [], "stresses": [], "applications": [ "batteries", "optics-and-cameras" ] }, "properties": [ { "benchmark": "melting_point", "label": "Melting point, ICSC card", "value": 690, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "form": "powder or solid, as printed on the card" }, "method": "Value printed on an International Chemical Safety Card", "status": "ground", "source": "icsc-0596", "where": "Physical and Chemical Information, Melting point", "source_detail": { "title": "International Chemical Safety Card 0596: Vanadium pentoxide", "id": "CAS 1314-62-1; ICSC 0596", "url": "https://chemicalsafety.ilo.org/dyn/icsc/showcard.display?p_card_id=0596", "kind": "database", "license": "ILO International Chemical Safety Cards (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, HSDB record in PubChem", "value": 681, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "basis": "PubChem experimental property, cited to the Hazardous Substances Data Bank" }, "method": "Value in PubChem experimental properties", "status": "ground", "note": "A second database value. The ICSC card gives 690 °C, so the two sources differ by 9 °C.", "source": "pubchem-v2o5", "where": "Experimental Properties, Melting Point (reference 35)", "source_detail": { "title": "PubChem compound record, Vanadium oxide (V2O5), CID 14814", "id": "CID 14814; CAS 1314-62-1; molecular formula O5V2", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/14814", "year": 2026, "kind": "database", "license": "public domain (NCBI)" } }, { "benchmark": "decomposition_temperature", "label": "Decomposition temperature", "value": 1750, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "atmosphere": "not stated in the record" }, "method": "Value in PubChem experimental properties, cited to the Hazardous Substances Data Bank", "status": "ground", "source": "pubchem-v2o5", "where": "Experimental Properties, Decomposition (reference 35)", "source_detail": { "title": "PubChem compound record, Vanadium oxide (V2O5), CID 14814", "id": "CID 14814; CAS 1314-62-1; molecular formula O5V2", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/14814", "year": 2026, "kind": "database", "license": "public domain (NCBI)" } }, { "benchmark": "density", "label": "Relative density, water = 1", "value": 3.4, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "basis": "relative density to water, as printed; the card gives no temperature" }, "method": "Value printed on an International Chemical Safety Card", "status": "ground", "note": "The card prints a relative density, not a density in g/cm3. PubChem gives 3.35 at 25 °C without a unit, and that value was not used.", "source": "icsc-0596", "where": "Physical and Chemical Information, Relative density (water = 1)", "source_detail": { "title": "International Chemical Safety Card 0596: Vanadium pentoxide", "id": "CAS 1314-62-1; ICSC 0596", "url": "https://chemicalsafety.ilo.org/dyn/icsc/showcard.display?p_card_id=0596", "kind": "database", "license": "ILO International Chemical Safety Cards (cited, not reproduced)" } }, { "benchmark": "water_solubility", "label": "Solubility in water", "value": 0.8, "bound": "exact", "unit": "g/100ml", "scope": "material", "conditions": { "temperature": "not stated on the card" }, "method": "Value printed on an International Chemical Safety Card", "status": "ground", "note": "PubChem's HSDB entry gives 0.07 g/100 g water at 25 °C, a much lower figure. The two sources disagree.", "source": "icsc-0596", "where": "Physical and Chemical Information, Solubility in water", "source_detail": { "title": "International Chemical Safety Card 0596: Vanadium pentoxide", "id": "CAS 1314-62-1; ICSC 0596", "url": "https://chemicalsafety.ilo.org/dyn/icsc/showcard.display?p_card_id=0596", "kind": "database", "license": "ILO International Chemical Safety Cards (cited, not reproduced)" } }, { "benchmark": "molecular_weight", "label": "Molecular weight, V2O5", "value": 181.88, "bound": "exact", "unit": "g/mol", "scope": "material", "conditions": { "basis": "computed from the formula V2O5" }, "method": "Computed property in the PubChem record", "status": "calculated", "source": "pubchem-v2o5", "where": "Computed Properties, Molecular Weight", "source_detail": { "title": "PubChem compound record, Vanadium oxide (V2O5), CID 14814", "id": "CID 14814; CAS 1314-62-1; molecular formula O5V2", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/14814", "year": 2026, "kind": "database", "license": "public domain (NCBI)" } }, { "benchmark": "temperature_coefficient_of_resistance", "label": "TCR, sputtered V2O5/V multilayer film, O2 anneal 30 min", "value": -3.0036, "bound": "exact", "unit": "%/K", "scope": "material", "conditions": { "film": "V2O5 and V 5 nm layers, 105 nm total, sputtered and annealed (a mixed VOx film, not bulk V2O5)", "anneal": "300 °C (573 K) in O2 for 30 min", "temperature": "about 298 K" }, "method": "Resistance against temperature measured on resistive thermometers; TCR from the paper's equation", "status": "ground", "source": "mdpi-bolometer-2019", "where": "Abstract, first results sentence; Results, Table 1", "source_detail": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" } }, { "benchmark": "temperature_coefficient_of_resistance", "label": "TCR, sputtered V2O5/V multilayer film, O2 anneal 40 min", "value": -2.4964, "bound": "exact", "unit": "%/K", "scope": "material", "conditions": { "film": "V2O5 and V 5 nm layers, 105 nm total, sputtered and annealed (a mixed VOx film, not bulk V2O5)", "anneal": "300 °C (573 K) in O2 for 40 min", "temperature": "about 298 K" }, "method": "Resistance against temperature measured on resistive thermometers; TCR from the paper's equation", "status": "ground", "source": "mdpi-bolometer-2019", "where": "Abstract, first results sentence; Results, Table 1", "source_detail": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" } }, { "benchmark": "temperature_coefficient_of_resistance", "label": "TCR, sputtered V2O5/V multilayer film, N2 anneal 30 min", "value": -3.18, "bound": "exact", "unit": "%/K", "scope": "material", "conditions": { "film": "V2O5 and V 5 nm layers, 105 nm total, sputtered and annealed (a mixed VOx film, not bulk V2O5)", "anneal": "300 °C (573 K) in N2 for 30 min", "temperature": "about 298 K" }, "method": "Resistance against temperature measured on resistive thermometers; TCR from the paper's equation", "status": "ground", "source": "mdpi-bolometer-2019", "where": "Abstract, second results sentence; Results, Table 1", "source_detail": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" } }, { "benchmark": "temperature_coefficient_of_resistance", "label": "TCR, sputtered V2O5/V multilayer film, N2 anneal 40 min", "value": -1.1181, "bound": "exact", "unit": "%/K", "scope": "material", "conditions": { "film": "V2O5 and V 5 nm layers, 105 nm total, sputtered and annealed (a mixed VOx film, not bulk V2O5)", "anneal": "300 °C (573 K) in N2 for 40 min", "temperature": "about 298 K" }, "method": "Resistance against temperature measured on resistive thermometers; TCR from the paper's equation", "status": "ground", "source": "mdpi-bolometer-2019", "where": "Abstract, second results sentence; Results, Table 1", "source_detail": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" } }, { "benchmark": "electrical_resistivity", "label": "Resistivity, sputtered V2O5/V multilayer film, O2 anneal 30 min", "value": 0.01477, "bound": "exact", "unit": "Ω·cm", "scope": "material", "conditions": { "film": "V2O5 and V 5 nm layers, 105 nm total, sputtered and annealed (a mixed VOx film, not bulk V2O5)", "anneal": "300 °C (573 K) in O2 for 30 min", "temperature": "about 298 K" }, "method": "Resistivity printed by the paper at room temperature", "status": "ground", "source": "mdpi-bolometer-2019", "where": "Abstract, first results sentence; Results, Table 1", "source_detail": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" } }, { "benchmark": "electrical_resistivity", "label": "Resistivity, sputtered V2O5/V multilayer film, O2 anneal 40 min", "value": 0.00819, "bound": "exact", "unit": "Ω·cm", "scope": "material", "conditions": { "film": "V2O5 and V 5 nm layers, 105 nm total, sputtered and annealed (a mixed VOx film, not bulk V2O5)", "anneal": "300 °C (573 K) in O2 for 40 min", "temperature": "about 298 K" }, "method": "Resistivity printed by the paper at room temperature", "status": "ground", "source": "mdpi-bolometer-2019", "where": "Abstract, first results sentence; Results, Table 1", "source_detail": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" } }, { "benchmark": "electrical_resistivity", "label": "Resistivity, sputtered V2O5/V multilayer film, N2 anneal 30 min", "value": 0.04718, "bound": "exact", "unit": "Ω·cm", "scope": "material", "conditions": { "film": "V2O5 and V 5 nm layers, 105 nm total, sputtered and annealed (a mixed VOx film, not bulk V2O5)", "anneal": "300 °C (573 K) in N2 for 30 min", "temperature": "about 298 K" }, "method": "Resistivity printed by the paper at room temperature", "status": "ground", "source": "mdpi-bolometer-2019", "where": "Abstract, second results sentence; Results, Table 1", "source_detail": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" } }, { "benchmark": "electrical_resistivity", "label": "Resistivity, sputtered V2O5/V multilayer film, N2 anneal 40 min", "value": 0.002527, "bound": "exact", "unit": "Ω·cm", "scope": "material", "conditions": { "film": "V2O5 and V 5 nm layers, 105 nm total, sputtered and annealed (a mixed VOx film, not bulk V2O5)", "anneal": "300 °C (573 K) in N2 for 40 min", "temperature": "about 298 K" }, "method": "Resistivity printed by the paper at room temperature", "status": "ground", "source": "mdpi-bolometer-2019", "where": "Abstract, second results sentence; Results, Table 1", "source_detail": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" } } ], "corrosion": [ { "environment": "Molten sodium sulfate and V2O5 salt at 700 to 800 °C (hot corrosion of a nickel alloy)", "headline": "V2O5 with sodium sulfate forms a molten salt that attacks nickel alloys at high temperature.", "effect": "In a crucible test with about 20% Na2SO4 and 80% V2O5, Inconel 625 corroded more the longer it was exposed. After 24 h, CrVO4 and Ni3V2O8 formed on the surface, and sulfur entered the alloy to form internal sulfides that sped up intergranular attack. The paper gives no corrosion-rate scale, so no rating is assigned here.", "rating": "unknown", "conditions": { "temperature": "700, 750 and 800 °C", "exposure": "24 to 120 h, weight-loss method", "salt": "about 20% Na2SO4 and 80% V2O5 (section 2.2)" }, "source": "metals-inconel-2023", "where": "Abstract; Section 2.2; Section 3.1" }, { "environment": "Aqueous acids and alkalis", "headline": "V2O5 dissolves in concentrated acids and alkalis, and forms vanadates in alkali.", "effect": "PubChem's HSDB-based summary says V2O5 is soluble in concentrated acids and alkalies and insoluble in alcohol, and that it forms vanadates in alkalis. The ICSC card gives a water solubility of 0.8 g/100 ml.", "rating": "unknown", "conditions": { "form": "powder", "temperature": "not stated" }, "source": "pubchem-v2o5", "where": "Experimental Properties, Solubility (reference 35); Other Experimental Properties (reference 35)" }, { "environment": "Heating above about 700 °C (oxygen loss)", "headline": "V2O5 loses oxygen on heating, and decomposes at 1750 °C to give irritating vanadium oxide fumes.", "effect": "The PubChem record says V2O5 loses oxygen reversibly between 700 and 1125 °C. When heated to decomposition it gives acrid smoke and irritating fumes of vanadium oxides. No ageing or reduction rate was found in a source read here.", "rating": "unknown", "conditions": { "temperature": "700 to 1125 °C for the reversible oxygen loss; decomposition at 1750 °C" }, "source": "pubchem-v2o5", "where": "Other Experimental Properties (reference 35); Decomposition (reference 35)" } ], "risks": { "hazards": [ { "text": "Signal word Danger. The EU harmonised classification listed in PubChem (Regulation (EC) No 1272/2008) gives H301 toxic if swallowed, H330 fatal if inhaled, H335 may cause respiratory irritation, H341 suspected of causing genetic defects, H350 may cause cancer, H361fd, H362, H372 causes damage to organs through prolonged or repeated exposure, and H411 toxic to aquatic life with long lasting effects.", "ghs": [ "H301", "H330", "H335", "H341", "H350", "H361fd", "H362", "H372", "H411" ], "source": "pubchem-v2o5", "where": "GHS Classification, Regulation (EC) No 1272/2008 entry (reference 48)" }, { "text": "PubChem gives a probable oral lethal dose for humans of 5 to 50 mg/kg, which the record says is about the same magnitude as pentavalent arsenic. Chronic bronchitis has been described in boiler cleaners exposed to the dust.", "ghs": [], "source": "pubchem-v2o5", "where": "Hazards Identification, Health Hazards (reference 6); Hazards Summary (reference 33)" }, { "text": "Occupational exposure limit on the ICSC card: TLV 0.05 mg/m3 as V, inhalable fraction, as TWA; A3, confirmed animal carcinogen with unknown relevance to humans.", "ghs": [], "source": "icsc-0596", "where": "Occupational Exposure Limits" }, { "text": "The aerosol irritates the eyes, skin and respiratory tract, and can be absorbed by inhalation and by ingestion. Upon heating, toxic fumes are formed, and the material is not combustible.", "ghs": [], "source": "icsc-0596", "where": "Exposure and Health Effects; Fire Hazard" } ], "failure_risks": [ { "mode": "Vanadate attack on a nickel alloy at high temperature", "trigger": "Sodium sulfate and V2O5 deposits from high-sulfur, high-vanadium fuel at 700 to 800 °C, in the crucible test", "consequence": "Corrosion of Inconel 625 rose with time and temperature. Sulfur entered the alloy and formed internal sulfides that sped up intergranular attack.", "severity": "high", "source": "metals-inconel-2023", "where": "Abstract; Introduction; Section 3.1" }, { "mode": "Film resistivity and TCR shift with the anneal", "trigger": "Changing the anneal atmosphere (O2 or N2) or time (30 or 40 min) of a sputtered V2O5/V multilayer", "consequence": "The TCR moved from -3.0036 to -2.4964 %/K in O2 and from -3.18 to -1.1181 %/K in N2. Resistivity in N2 fell from 0.04718 to 0.002527 Ω·cm.", "severity": "moderate", "source": "mdpi-bolometer-2019", "where": "Abstract; Results, Table 1" } ], "side_effects": [ { "text": "When heated to decomposition, V2O5 gives acrid smoke and irritating fumes of vanadium oxides, and the record notes that it may increase the intensity of a fire when in contact with combustible materials.", "affects": "People and equipment near a fire or a hot process", "source": "pubchem-v2o5", "where": "Experimental Properties, Decomposition (reference 35); Fire Hazards (reference 6)" } ], "handling": [ { "text": "Prevent dispersion of dust. Use ventilation, local exhaust or breathing protection, gloves, and safety goggles, and do not eat, drink or smoke at work.", "source": "icsc-0596", "where": "Prevention" }, { "text": "Store separated from food and feedstuffs, and do not transport with food.", "source": "icsc-0596", "where": "Storage; Packaging" }, { "text": "For spills, moisten the powder first to prevent dusting, sweep it into covered containers, and do not let the chemical enter the environment.", "source": "icsc-0596", "where": "Spillage disposal" } ], "mitigations": [ { "text": "Keep airborne vanadium below the ICSC TLV of 0.05 mg/m3 (as V, inhalable fraction, TWA).", "source": "icsc-0596", "where": "Occupational Exposure Limits" }, { "text": "Use a particulate filter respirator adapted to the airborne concentration when clearing a spill, as the ICSC card advises.", "source": "icsc-0596", "where": "Spillage disposal" } ] }, "uses": [ { "application": "batteries", "device": "Vanadium redox flow battery for grid-scale energy storage", "example": "The USGS says vanadium redox flow batteries continued to be used in large-scale energy storage in 2025, because of their operational safety, long cycle life and suitability for medium- to long-duration use. It calls high-purity vanadium feedstock a key challenge.", "source": "usgs-mcs2026-vanadium", "where": "Events, Trends, and Issues (vanadium chapter)" }, { "application": "optics-and-cameras", "device": "Uncooled infrared microbolometer thermometer film, lab-made from sputtered V2O5 and vanadium layers", "example": "Annealed at 300 °C, the films reached TCRs between -1.1181 and -3.18 %/K, depending on the anneal atmosphere and time. The authors say the films have TCR and resistivity properties suitable for microbolometer applications.", "source": "mdpi-bolometer-2019", "where": "Abstract; Conclusions" } ], "supply": [ { "subject": "Vanadium (feedstock for V2O5 and vanadium alloys)", "producers": [ { "country": "China", "share_percent": 71.2, "year": 2024 }, { "country": "Russia", "share_percent": 17.8, "year": 2024 }, { "country": "South Africa", "share_percent": 6.8, "year": 2024 }, { "country": "Brazil", "share_percent": 4.4, "year": 2024 } ], "critical_lists": [ { "list": "USGS 2025 List of Critical Minerals (entry: Vanadium, used to strengthen iron and steel)", "listed": true }, { "list": "EU critical raw materials list, fifth list of 34 (2023), as shown on the European Commission page", "listed": true } ], "recycling": "USGS: recycling of vanadium is mainly reprocessing of vanadium catalysts into new catalysts.", "substitutes": [ "USGS: platinum and nickel can replace vanadium compounds as catalysts in some chemical processes.", "USGS: no acceptable substitute for vanadium is available for use in aerospace titanium alloys." ], "source": "usgs-mcs2026-vanadium", "where": "World Mine Production and Reserves table, 2024 column, vanadium content in thousand metric tons. Shares calculated by Space Mushroom against the printed 2024 world total of 118,000. The China and Russia figures are marked e (estimated) in the USGS table. The 2025e column does not add up to its printed world total, so it was not used. Recycling; Substitutes. Critical lists: usgs-crit2025 and ec-crm." }, { "subject": "Vanadium pentoxide, U.S. import sources (not world production)", "producers": [ { "country": "Brazil", "share_percent": 47 }, { "country": "South Africa", "share_percent": 43 }, { "country": "Russia", "share_percent": 6 }, { "country": "Other", "share_percent": 4 } ], "critical_lists": [], "recycling": "USGS: vanadium pentoxide is recovered from processed waste materials such as petroleum residues, spent catalysts and utility ash in the United States.", "substitutes": [], "source": "usgs-mcs2026-vanadium", "where": "Import Sources (2021-24), vanadium pentoxide, as printed in the USGS vanadium chapter. The year field is left out because the USGS gives a 2021 to 2024 range." } ], "media": [], "documents": [ { "title": "International Chemical Safety Card 0596: Vanadium pentoxide", "type": "database", "url": "https://chemicalsafety.ilo.org/dyn/icsc/showcard.display?p_card_id=0596" }, { "title": "PubChem: Vanadium oxide (V2O5), CID 14814, computed and experimental properties and GHS classification", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/14814", "year": 2026 }, { "title": "Mineral Commodity Summaries 2026: Vanadium (USGS)", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-vanadium.pdf", "year": 2026 }, { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Sensors 2019, 19, 1320)", "type": "paper", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019 }, { "title": "Hot Corrosion Behavior of Inconel 625 in Na2SO4 and V2O5 Molten Salt System (Metals 2023, 13, 1069)", "type": "paper", "url": "https://www.mdpi.com/2075-4701/13/6/1069", "year": 2023 }, { "title": "A Comparative Study about Production of Vanadium Carbide (Archives of Metallurgy and Materials 2024, 69, 257-262)", "type": "paper", "url": "https://czasopisma.pan.pl//Content/130944/PDF/AMM-2024-1-42-Bugdayci.pdf", "year": 2024 }, { "title": "Theoretical study of the crystal structure, stability, and properties of phases in the V-N system (Physical Review B 104, 134111, 2021)", "type": "paper", "url": "https://uspex-team.org/static/file/Zhang2021.pdf", "year": 2021 } ], "gaps": [ "No safety data sheet for V2O5 from a supplier was read in this run. The Sigma-Aldrich and Parchem SDS pages were found in search but not opened, so the hazard codes rest on PubChem's aggregated notifications, the ICSC card and the EU entry in PubChem.", "The hazard codes differ between sources. Wikipedia's infobox lists H302, H332, H335, H341, H361, H372 and H411, while PubChem's aggregate lists H301 and H330. Only the PubChem and ICSC data were used.", "Melting point (681 and 690 °C) and water solubility (0.8 g/100 ml on the ICSC card against 0.07 g/100 g in PubChem) disagree between sources. Both values are kept and labelled.", "The 3.35 and 3.36 density values in PubChem have no printed unit, so they were not used. The ICSC card gives relative density 3.4 (water = 1) instead.", "No bulk V2O5 hardness, elastic modulus, thermal expansion or thermal conductivity was found in a source read in this run.", "The TCR and resistivity values are for sputtered mixed VOx multilayer films with vanadium metal, not for bulk V2O5. No measured TCR for bulk V2O5 was found.", "The USGS chapter does not tie the flow-battery demand to V2O5 specifically: it discusses vanadium feedstock. No peer-reviewed source read in this run describes making a flow-battery electrolyte from V2O5.", "Catalysis (sulfuric acid and maleic anhydride), a major use named by the USGS and PubChem, is not in the allowed application list, so it is given only in the story section.", "No space, vacuum, radiation or flight result for V2O5 or its films was found in a source read in this run.", "Crustal abundance of vanadium was not read in a source opened for this profile.", "The water solubility is recorded as printed, in g/100ml. The name water_solubility is not in the canonical property list, so it is a short snake_case name.", "The USGS 2025e column for vanadium does not add up to its printed world total, so the shares use the 2024 column, which does.", "The Wikipedia infobox gives the crystal system and space group. Its lattice constants and density were not used, because the Wikipedia pages are for composition and history only.", "Vanadium nitride: the density and melting point were not confirmed in a source read here. A search snippet gave 2,050 and 2,320 °C for the melting point, and those figures were not used. The only value kept is a calculated hardness.", "Vanadium carbide: the values come from one 2024 paper. A thermal expansion value in the same sentence is left out.", "The hot-corrosion paper gives no corrosion-rate scale, so the corrosion rating is unknown. Only the abstract and the first sections were read.", "The related sections (vanadium carbide and nitride) are kept in the top-level related key. The site schema does not declare that key, so the site will not display it until the schema is extended.", "No media (figures or photographs) were added. The lithium iron phosphate profile has three media entries; this profile has none.", "verify-values could not read the PubChem page (it returns a verification screen) or the MDPI bolometer page (HTTP 403). Those values were read in this run from the PubChem REST data and from the MDPI page in a browser, so they were checked by hand, not by the script." ], "story": { "why": "Vanadium pentoxide is used in industry as a catalyst for sulfuric acid and maleic anhydride, and as a route to vanadium metal and ferrovanadium. In this collection it matters for flow batteries and for infrared sensor films, both of which depend on vanadium chemistry. The data come from safety cards, databases and laboratory papers. No flight record for V2O5 itself was found.", "uses": [ { "where": "Catalysts for sulfuric acid and maleic anhydride", "line": "The USGS says the major non-metallurgical use of vanadium is in catalysts that make maleic anhydride and sulfuric acid." }, { "where": "Flow batteries", "line": "The USGS says vanadium redox flow batteries kept being used for large-scale energy storage in 2025, and it calls high-purity vanadium feedstock a key challenge." }, { "where": "Infrared sensor films (laboratory)", "line": "Sputtered V2O5 and vanadium films, annealed at 300 °C, reached TCRs between -1.1181 and -3.18 %/K. The authors say they suit microbolometer applications." }, { "where": "Glazes and glass", "line": "PubChem lists V2O5 as a ceramic colouring material and as an agent that inhibits UV transmission in glass." } ], "can_do": [ { "label": "Thermal sensing (lab film)", "line": "A sputtered V2O5 and vanadium multilayer annealed in N2 for 30 min reached -3.18 %/K at a resistivity of 0.04718 Ω·cm.", "scope": "material", "value": "TCR -3.18 %/K" }, { "label": "Catalysis", "line": "The USGS names both as the main non-metallurgical catalyst uses of vanadium.", "scope": "material", "value": "Sulfuric acid and maleic anhydride" }, { "label": "Melting point", "line": "The ICSC card gives a melting point of 690 °C. PubChem's HSDB record gives 681 °C.", "scope": "material", "value": "690 °C" } ], "compare": "V2O5 melts at 690 °C and decomposes at 1750 °C. Its film TCRs in this record range from -1.1181 to -3.18 %/K, depending on the anneal, so the anneal is the main control on the film result. The carbide and nitride in the related section are hard materials, and their hardness values are given there.", "compare_rows": [ { "label": "Melting point", "benchmark": "melting_point", "scope": "material" }, { "label": "Decomposition", "benchmark": "decomposition_temperature", "scope": "material" }, { "label": "Density (relative)", "benchmark": "density", "scope": "material" } ], "handling": [ "Prevent dust. Use ventilation or breathing protection, gloves and goggles.", "Store away from food and feedstuffs, and keep the powder out of the environment.", "Clean spills by moistening first, then sweeping into covered containers." ], "good_for": [ "Vanadium redox flow batteries. The USGS reports continued use for long-duration grid storage in 2025.", "Laboratory infrared sensor films. Annealed V2O5 and vanadium films reached TCRs of -1.1181 to -3.18 %/K." ], "watch_out": [ "Toxicity. The EU harmonised classification lists H301, H330 and H350, and PubChem gives a probable oral lethal dose of 5 to 50 mg/kg.", "Dust. The ICSC card calls for dust control, with an exposure limit of 0.05 mg/m3 as V.", "Molten salt. With sodium sulfate at 700 to 800 °C, V2O5 attacks nickel alloys such as Inconel 625.", "Conflicting data. Melting point 681 or 690 °C, and water solubility 0.8 g/100 ml on the ICSC card against 0.07 g/100 g in PubChem." ], "verdict": "V2O5 is a well-studied oxide with a clear industrial role in catalysis and a place in flow batteries. It is toxic as powder and fume, and the infrared results come from laboratory films rather than bulk material, so treat those values as laboratory data.", "recipe": { "line": "V2O5 is an oxide of vanadium with two vanadium and five oxygen per formula unit. Vanadium can take several oxidation states, which is the basis of its redox and catalytic chemistry.", "parts": [ { "name": "Vanadium", "symbol": "V", "role": "The metal centre. Vanadium changes between oxidation states as the oxide is reduced or reoxidised, which is what makes it useful in batteries and catalysts." }, { "name": "Oxygen", "symbol": "O", "role": "Bonded to the vanadium in the orthorhombic lattice. The oxide gives up oxygen reversibly between 700 and 1125 °C." } ] }, "risk_groups": [ { "title": "For people", "lead": "The EU harmonised classification in PubChem carries the Danger signal word. The ICSC card sets an exposure limit of 0.05 mg/m3 as V.", "points": [ { "label": "Inhaled", "line": "Fatal if inhaled (H330), and may cause respiratory irritation (H335). The ICSC card calls the aerosol irritating to the eyes, skin and respiratory tract." }, { "label": "Swallowed", "line": "Toxic if swallowed (H301). PubChem gives a probable oral lethal dose for humans of 5 to 50 mg/kg." }, { "label": "Long term", "line": "Suspected of causing genetic defects (H341), may cause cancer (H350), and causes organ damage through repeated exposure (H372)." }, { "label": "In a fire", "line": "Heating gives acrid smoke and irritating fumes of vanadium oxides. The ICSC card says toxic fumes form on heating." } ], "level": 3, "verdict": "Toxic dust and fume, H330 fatal if inhaled" }, { "title": "Handling and storage", "points": [ { "label": "Dust", "line": "Prevent the dust from spreading. Use ventilation or breathing protection, and gloves and goggles." }, { "label": "Storage", "line": "Store away from food and feedstuffs." }, { "label": "Spills", "line": "Moisten the powder first to stop it dusting, then sweep it into covered containers." } ] }, { "title": "If heated or in a melt", "lead": "These effects come from laboratory and industrial data, not from incidents.", "points": [ { "label": "Molten salt", "line": "With sodium sulfate at 700 to 800 °C, the melt attacks Inconel 625. Corrosion rose with time, and sulfur formed internal sulfides in the alloy." }, { "label": "Film anneal", "line": "In lab films, changing the N2 anneal from 30 to 40 min moved the TCR from -3.18 to -1.1181 %/K." } ] } ] }, "updated": "2026-10-26", "review": { "status": "draft", "method": "assistant", "checked_values": 14, "unreachable": 0, "caveats": 4, "note": "Read by an AI assistant on 2026-10-26 from the pages and PDFs fetched in that run: the ICSC card, the PubChem record (REST data), the Sensors 2019 and Metals 2023 pages, the USGS vanadium chapter and critical list page, the EC page, the Archives 2024 PDF and the PRB 2021 PDF. Search snippets were not used as values. Caveats: the TCR and resistivity values are for lab films, not bulk V2O5; the hazard codes differ between sources; the melting point and water solubility disagree between sources; the vanadium carbide and nitride sections rest on one paper each." }, "sources": { "icsc-0596": { "title": "International Chemical Safety Card 0596: Vanadium pentoxide", "id": "CAS 1314-62-1; ICSC 0596", "url": "https://chemicalsafety.ilo.org/dyn/icsc/showcard.display?p_card_id=0596", "kind": "database", "license": "ILO International Chemical Safety Cards (cited, not reproduced)" }, "pubchem-v2o5": { "title": "PubChem compound record, Vanadium oxide (V2O5), CID 14814", "id": "CID 14814; CAS 1314-62-1; molecular formula O5V2", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/14814", "year": 2026, "kind": "database", "license": "public domain (NCBI)" }, "usgs-mcs2026-vanadium": { "title": "Mineral Commodity Summaries 2026, Vanadium", "id": "USGS MCS 2026, February 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-vanadium.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "usgs-crit2025": { "title": "About the 2025 List of Critical Minerals (USGS, final list of 60 minerals, November 2025)", "id": "Final 2025 List of Critical Minerals", "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals", "year": 2025, "kind": "web", "license": "public domain (USGS)" }, "ec-crm": { "title": "Critical raw materials (European Commission, fifth list of 34 critical raw materials)", "id": "Regulation (EU) 2024/1252 (the page does not print the number)", "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en", "year": 2023, "kind": "web", "license": "European Commission web page" }, "mdpi-bolometer-2019": { "title": "Temperature-Dependent Resistive Properties of Vanadium Pentoxide/Vanadium Multi-Layer Thin Films for Microbolometer and Antenna-Coupled Microbolometer Applications (Abdel-Rahman, Zia, Alduraibi; Sensors)", "id": "doi:10.3390/s19061320", "url": "https://www.mdpi.com/1424-8220/19/6/1320", "year": 2019, "kind": "paper", "license": "CC BY 4.0" }, "metals-inconel-2023": { "title": "Hot Corrosion Behavior of Inconel 625 in Na2SO4 and V2O5 Molten Salt System (Li et al.; Metals)", "id": "doi:10.3390/met13061069", "url": "https://www.mdpi.com/2075-4701/13/6/1069", "year": 2023, "kind": "paper", "license": "CC BY 4.0" }, "wikipedia-v2o5": { "title": "Vanadium(V) oxide, Wikipedia (infobox only: crystal system and space group)", "url": "https://en.wikipedia.org/wiki/Vanadium(V)_oxide", "kind": "web", "license": "CC BY-SA 4.0" }, "amm-vc-2024": { "title": "A Comparative Study about Production of Vanadium Carbide (Bugdayci et al.; Archives of Metallurgy and Materials 69, 1, 257-262)", "id": "doi:10.24425/amm.2024.147816", "url": "https://czasopisma.pan.pl//Content/130944/PDF/AMM-2024-1-42-Bugdayci.pdf", "year": 2024, "kind": "paper", "license": "open access (cited, not reproduced)" }, "uspex-vn-2021": { "title": "Theoretical study of the crystal structure, stability, and properties of phases in the V-N system (Zhang et al.; Physical Review B 104, 134111)", "id": "doi:10.1103/PhysRevB.104.134111", "url": "https://uspex-team.org/static/file/Zhang2021.pdf", "year": 2021, "kind": "paper", "license": "cited, not reproduced" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/vanadium-pentoxide/" }