Vanadium
Atomic Data
| Atomic Number | 23 |
| Symbol | V |
| Atomic Weight | 50.942 u |
| Density (STP) | 6.0 g/cm³ |
| Melting Point | 1909.85 °C (2183 K) |
| Boiling Point | 3406.85 °C (3680 K) |
| Electronegativity | 1.63 (Pauling) |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d3 4s2 |
| Oxidation States | +2, +3, +4, +5 |
| Phase at STP | Solid |
| Category | Transition Metal |
| Period / Group | 4 / 5 |
| CAS Number | 7440-62-2 |
Electron Configuration
[Ar] 3d3 4s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 3 | 21 |
| N | 4 | 4s | 2 | 23 |
| Total | 23 | 23 | ||
Isotopes of Vanadium
Vanadium has two naturally occurring isotopes, 50V and 51V, both considered stable for practical purposes. 51V is overwhelmingly dominant at 99.75% natural abundance, while 50V accounts for just 0.25%.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Vanadium-50 | ⁵₀V | 23 | 27 | 0.25% | Stable |
| Vanadium-51 | ⁵¹V | 23 | 28 | 99.75% | Stable |
Abundance & Occurrence
Vanadium occurs at about 120 ppm in Earth's crust, making it the 20th most abundant element, and is found mainly in vanadium-bearing magnetite ores, phosphate rock, and fossil fuel deposits. The largest commercial producers are China, Russia, and South Africa, where vanadium is primarily recovered as a by-product of steel slag processing and titaniferous magnetite smelting.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Safety & Handling
- Compound Toxicity: Vanadium compounds are toxic, particularly vanadium pentoxide (V2O5), which can cause severe respiratory irritation, bronchoconstriction, and systemic effects on inhalation. Chronic exposure has been linked to lung damage and nervous system effects.
- Inhalation Hazard: Dust and fumes from vanadium compounds must not be inhaled. Respiratory protection, local exhaust ventilation, and enclosed handling systems are required in industrial settings where vanadium dust or fumes are generated.
- Skin and Eye Contact: Vanadium compounds can irritate and stain the skin green or black on contact. Eye protection and chemical-resistant gloves should be worn when handling vanadium salts, oxides, or solutions.
- Fire Hazard: Bulk vanadium metal is not considered flammable. However, finely divided vanadium powder can be combustible and should be stored away from ignition sources and oxidising agents.
- Storage: Vanadium metal and its compounds should be stored in sealed containers in a cool, dry, well-ventilated area, away from strong acids, alkalis, and oxidisers. Vanadium pentoxide in particular should be handled with full PPE at all times.
Vanadium in the Real World
Real-World Uses
- High-strength steel alloys — Vanadium is added in small amounts (0.1–0.2%) to steel to form vanadium carbides and nitrides, which dramatically increase tensile strength, hardness, and wear resistance. Vanadium steel is used in tool steel, high-speed cutting tools, automotive axles, crankshafts, and construction reinforcing bar.
- Vanadium redox flow batteries — Vanadium's four accessible oxidation states (+2, +3, +4, +5) make it ideal as the electrolyte in redox flow batteries. These systems offer very long cycle life and scalable capacity, making them a leading technology for grid-scale energy storage alongside solar and wind power installations.
- Catalytic sulfuric acid production — Vanadium pentoxide (V2O5) is the industrial catalyst used in the contact process for manufacturing sulfuric acid, one of the world's most produced chemicals. It oxidises sulfur dioxide to sulfur trioxide at 400–600 °C with high efficiency.
- Titanium alloy additive — The titanium-aluminium-vanadium alloy Ti-6Al-4V is the most widely used titanium alloy in the world. Vanadium stabilises the beta phase of titanium, improving strength, machinability, and fatigue resistance for aerospace engine components, airframes, and medical implants.
- Aerospace components — Beyond titanium alloys, vanadium is used in superalloys and specialty steels for jet engine turbine blades, rocket motor casings, and other high-temperature structural components where strength retention at elevated temperatures is critical.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
What is vanadium used for?
Vanadium's largest use is as an additive in high-strength steel alloys, where even small amounts dramatically increase toughness, strength, and wear resistance. It is also the active electrolyte material in vanadium redox flow batteries used for large-scale energy storage, a catalyst (as vanadium pentoxide) in the industrial production of sulfuric acid, and an additive in titanium alloys for aerospace components.
Who discovered vanadium?
Vanadium was first discovered in 1801 by Spanish-Mexican mineralogist Andrés Manuel del Río, who found it in a lead ore from Mexico and initially called it "erythronium." However, his discovery was dismissed by European chemists who believed it was impure chromium. The element was independently rediscovered in 1830 by Swedish chemist Nils Gabriel Sefström, who named it vanadium after Vanadis, the Norse goddess of beauty, for its strikingly colourful compounds.
Is vanadium toxic?
Elemental vanadium metal presents a low acute toxicity hazard under normal handling conditions. However, vanadium compounds — particularly vanadium pentoxide — are toxic and can cause serious lung irritation, bronchoconstriction, and systemic effects if inhaled as dust or fumes. Skin and eye contact with vanadium compounds should be avoided, and appropriate PPE must be worn in industrial or laboratory settings.
Why is vanadium important for batteries?
Vanadium redox flow batteries (VRFBs) exploit the ability of vanadium ions to exist in four different oxidation states (+2, +3, +4, +5) in aqueous solution. This means both the positive and negative electrolytes use vanadium ions, eliminating cross-contamination between the two half-cells and giving VRFBs an exceptionally long cycle life. They are well suited for large-scale stationary energy storage to balance grid supply and demand from renewable sources.