Li-CO₂ batteries could be a two-in-one solution to the current problems of storing renewable energy and taking carbon emissions out of the air. They absorb carbon dioxide and convert it into a white powder called lithium carbonate while discharging energy.

These batteries could have profound implications for cutting emissions from vehicles and industry—and might even enable long-duration missions on Mars, where the atmosphere is 95% CO₂.

To make these batteries commercially viable, researchers have mainly been wrestling with problems related to recharging them. Now, our team at the University of Surrey has come up with a promising way forward. So how close are these “CO₂-breathing” batteries to becoming a practical reality?