Ellen Phiddian
Cosmos science journalist
Easy to scale up, hard to run down and without the need for lithium, vanadium flow batteries are becoming an exciting addition to the energy transition.
Vanadium batteries are known for having long lifespans, but a team of Brazilian researchers has landed on a way to make them last even longer.
Their results are published in Chemical Engineering Journal.
Vanadium flow batteries use liquid vanadium to transfer charge, and therefore electricity. This makes them less vulnerable to “capacity loss” ̶ a battery’s reduced ability to charge and discharge over time.
Capacity loss is caused by cross contamination: substances inside the battery reacting with each other in ways they shouldn’t, slowly building up materials that prevent electricity moving around.
Capacity loss can still happen in vanadium batteries, but unlike traditional batteries, it’s much easier to reverse – and turn those materials back into useful compounds.
“Energy efficiency loss due to aging is minimal,” says senior author Professor Ernesto Pereira, a researcher at Federal University of São Carlos, Brazil.
Pereira and colleagues used computer modelling as well as lab tests on small vanadium flow batteries to figure out how best to prevent capacity loss.
They found two properties of the battery had the most influence: current density, and concentration of active species (that is, compounds that transfer charge in the battery).
By tuning these two factors, they were able to mitigate contamination – and therefore, make the batteries last longer.
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