Though electric vehicles (EVs) emit much fewer greenhouse gas emissions than cars that burn petrol or diesel, the rare metals needed for manufacturing their batteries are increasingly in short supply. Currently, the EU recycles less than five percent of EV batteries, and the most common technique involves melting everything down to extract the precious metals — a very energy-intensive process.

However, thanks to new biotechnologies, a much better way of recycling old batteries is coming into view, with scientists arguing that bacteria might be the ideal candidate to do the job in an effective and environmentally friendly manner.

Bugs for batteries

One of the proponents of using bacteria to recycle precious metals from EV batteries is Sebastian Farnaud, a researcher and professor at Coventry University in the UK. In a recent piece for The Conversation, he explains how a process called bioleaching, or biomining, employs microbes that can oxidize metal as part of their metabolism.

How it works

The technique isn’t new and has already been widely used in the mining industry, where microorganisms are employed to extract valuable metals from ores. The same process has also been used to recover precious metals from circuit boards and solar panels.

Bioleaching involves growing bacteria in incubators at 37°C (98°F). Compared to traditional recycling methods, the process has a significantly smaller carbon footprint, making it a much greener alternative.

“Rather than remaining an afterthought, recycling can become both the beginning and end of an EV battery’s life cycle with bioleaching,” Farnaud argues, “Producing high-quality raw materials for new batteries at a low environmental cost.”

This story is part of our ‘Best of 2021’ series highlighting our top solutions from the year. Today we’re featuring science solutions.