Why in news?
Researchers at the University of Córdoba in Spain have developed a laboratory zinc–air battery that uses vitamin B12 as a catalyst at the air electrode. The vitamin helps the reactions involved in releasing electricity and recharging the cell. The team's university announcement reports up to 250 charge–discharge cycles. The work, published in the Journal of Materials Chemistry A, explores a new use for a biological molecule in battery materials. Its central advance is a B12-based electrode that supports both directions of the oxygen reaction needed in a rechargeable zinc–air cell.
What a zinc–air battery uses
A zinc–air battery combines a zinc electrode with an air electrode that uses oxygen from the surrounding air. During discharge, chemical reactions involving zinc and oxygen release electrical energy. An external circuit carries electrons through the device being powered.
Inside the battery, the electrolyte allows charged particles called ions to move. Electron movement in the external circuit and ion movement inside the cell work together to carry charge. In the Córdoba research, the electrolyte is water-based and alkaline.
Drawing oxygen from outside reduces the amount of reacting material that must be stored inside the cell. Zinc–air chemistry is already used in small devices such as hearing aids. Making this chemistry work repeatedly as a rechargeable system requires suitable electrode materials and reactions that can run in both directions.
The job of the B12 catalyst
A catalyst helps a chemical reaction proceed more readily. Vitamin B12, also called cobalamin, contains a cobalt centre within a larger molecular structure. The researchers use this structure to support reactions at the air electrode.
During discharge, oxygen at the air electrode accepts electrons in the oxygen reduction reaction. During charging, an external electricity supply drives the reverse process, including the oxygen evolution reaction, which releases oxygen. The team's B12-based material promotes both reactions. This two-way activity is the feature that helps make the experimental cell rechargeable.
Why attach the vitamin to carbon?
Vitamin B12 dissolves readily in water. A water-based cell therefore needs a way to hold the catalytic material in place. The team attached the B12 molecules to single-walled carbon nanotubes, very small tube-shaped carbon structures that provide a supporting surface.
The resulting combination keeps the molecular catalyst associated with the electrode. It also brings the catalyst into a material that can be used in an electrical device. The researchers examined its chemical structure and electrochemical behaviour to understand how the combined material works.
What the experiments show
The university reports that the prototype achieved up to 250 charge–discharge cycles. A cycle involves charging the cell and then drawing energy from it. Repeated cycling tests how the electrode continues to function as the reactions are driven in each direction.
The paper also examines declining capacity during use. Its analysis links the eventual decline to a build-up of zinc-containing material over the catalyst surface. This can cover the active material and make it harder for the reactions to proceed. Understanding that change helps explain why an initially effective electrode can lose performance over time.
Why battery-material research matters
A rechargeable battery has to combine several properties: useful energy storage, efficient charging and discharging, a suitable lifetime and practical materials. Research on the electrodes and electrolyte examines how those properties arise from the chemistry inside the cell.
The Córdoba study adds a molecular catalyst approach to that work. Its design connects a biological molecule with a carbon support and tests how the resulting air electrode performs. This gives researchers a way to study the relation between molecular structure, oxygen reactions and repeated battery operation.
Conclusion
The research demonstrates a B12-based catalyst for the air electrode of a rechargeable zinc–air prototype. Its value lies in supporting both oxygen reactions and showing how the catalyst's attachment and surface condition affect repeated use.
Sources
- García-Caballero and colleagues: B12-based air electrode research in Journal of Materials Chemistry A
- University of Córdoba: catalyst design, carbon support and reported cycling result
- University research dataset: B12-functionalised carbon nanotubes and zinc–air electrode measurements
- Anthropocene, November 2026: reporting on the battery research
- US Department of Energy: electrodes, electrolyte and rechargeable battery operation