Vanadium

Vanadium allows improving the mechanical properties of certain steels even when added in small amounts. It favours the formation of very fine particles that hinder the movement of dislocations in the metal, increasing its resistance and hardness. It also helps control grain size during heat treatment. For these reasons, vanadium steels are used in tools, car components, parts subjected to large stresses and structures needing high mechanical resistance.

Vanadium pentoxide, chemical formula V₂O₅, is used as a catalyst in important industrial processes. One of the best known is the contact process for manufacturing sulfuric acid, where it facilitates the conversion of sulfur dioxide into sulfur trioxide. Vanadium can temporarily change its oxidation state during the catalytic cycle, helping to transfer oxygen between substances. The catalyst accelerates the reaction without being consumed in net terms, allowing efficient industrial production.

Vanadium is part of some high-performance alloys, including certain titanium alloys and metallic systems designed for demanding conditions. Depending on composition, it can contribute to adjusting mechanical resistance, structural stability and behaviour at high temperatures. These properties are interesting in components where it is important to combine resistance and weight reduction. However, vanadium is not added to all aerospace alloys: its usefulness depends on the properties sought and how it interacts with the other elements.

Vanadium's different oxidation states allow its compounds to participate in electron transfer reactions, a property exploited in electrochemical technologies. In addition to flow batteries, vanadium oxides are investigated for electrodes, energy storage devices and materials whose conductivity changes with external conditions. Some oxides also present transitions between electronic states with different properties. Not all these uses have the same commercial development: several are still the subject of research to improve their stability, efficiency and cost.

Vanadium redox flow batteries store energy through reversible chemical reactions of their dissolved ions in liquid electrolytes. During charging and discharging, vanadium changes between different oxidation states, allowing storage or release of electrical energy. Unlike many conventional batteries, the stored energy depends mainly on electrolyte volume, while power depends on the size of the electrochemical cell. This feature allows designing long-duration energy storage systems for power grids and renewable energies.

Vanadium compounds can present green, blue, yellow, orange or violet colours, depending on their chemical composition and the environment of their atoms. One cause is that vanadium can adopt different oxidation states, which modify the electronic transitions responsible for absorbing certain light wavelengths. The solvent, acidity and presence of other substances can also influence colour. That is why changes in tonalities can help study chemical reactions containing vanadium.

Yes. One of the most relevant applications of vanadium in the energy sector is redox flow batteries, which can store electricity generated by solar and wind installations and return it when production decreases. Its capacity to utilise large deposits of electrolyte allows expanding stored energy without proportionally increasing the size of the electrochemical cell. In addition, the use of vanadium in both electrolytes can reduce certain problems associated with cross-contamination between chemical species, although cost, efficiency and maintenance remain important factors.