While flow battery designs are suited to storing large amounts of energy cheaply, they have previously relied on chemicals that are expensive or difficult to maintain, driving up costs.

Most previous flow batteries have chemistries based on metals. Vanadium is used in the most commercially advanced flow battery technology, but its cost is relatively high. Other variants contain precious metal catalysts such as platinum.

The researchers say their new battery already performs as well as vanadium flow batteries, but uses no precious metal catalyst and has an underlying chemistry that is metal-free, instead relying on naturally abundant, more affordable chemicals called quinones.

BBC News – Battery advance could boost renewable energy take-up.