200mw swedish all-vanadium liquid flow battery energy storage

Does vanadium degrade in flow batteries?

Vanadium does not degrade in flow batteries. According to Brushett, 'If you put 100 grams of vanadium into your battery and you come back in 100 years, you should be able to recover 100 grams of that vanadium—as long as the battery doesn’t have some sort of a physical leak'.

Can a flow battery be modeled?

MIT researchers have demonstrated a modeling framework that can help model flow batteries. Their work focuses on this electrochemical cell, which looks promising for grid-scale energy storage—except for one problem: Current flow batteries rely on vanadium, an energy-storage material that’s expensive and not always readily available.

Why is vanadium a challenge?

As grid-scale energy storage demands grow, particularly for long-duration storage, so will the need for flow batteries. This increased demand will lead to a challenge with vanadium. Rodby explains, 'Vanadium is found around the world but in dilute amounts, and extracting it is difficult.'

Does vanadium cross contaminate electrolytes?

In flow batteries, vanadium does not permanently cross-contaminate the electrolytes. If some vanadium flows through the membrane to the other side, it only causes a shift in the oxidation states, which can be easily remedied by rebalancing the electrolyte volumes and restoring the oxidation state via a minor charge step.

Why is extracting vanadium difficult?

“Vanadium is found around the world but in dilute amounts, and extracting it is difficult. Demand for vanadium will grow, and that will be a problem. As the grid becomes increasingly dominated by renewables, more and more flow batteries will be needed to provide long-duration storage.

What is 'crossover' in flow batteries?

In flow batteries, a phenomenon called 'crossover' occurs. The membrane is designed to allow small supporting ions to pass through and block the larger active species, but in reality, it isn’t perfectly selective, leading to a relatively faster form of degradation.