Batteries for electric vehicles are notoriously difficult to recycle, but growing demand for the rare metals they contain is leading to innovative new ways of retrieving them from used power cells.

I am standing in a lab where batteries go to be reborn. But first, they must be shredded.

What arrives here is a dark powder called "black mass" – a substance derived from pulverising batteries almost to oblivion. Each particle is less than a millimetre across. Staff working for Altilium, a recycling firm in the south-west of England, are now tasked with extracting crucial materials from this pitch black disorder.

The powder contains some plastic and steel from the battery which must be separated out, but there are also sought-after materials such as lithium, nickel, cobalt and graphite. These are the prized ingredients with which the lab workers here can make a new battery.

As the climate crisis intensifies, the world is electrifying. Countries are increasingly shifting away from fossil fuels towards renewable sources of energy including solar panels and wind turbines. Homeowners are installing heat pumps in the place of old gas or oil boilers. And drivers are increasingly buying electric vehicles (EVs) powered by batteries.

According to the International Energy Agency (IEA), nearly one in five cars sold in 2023 was electric. This was a 35% year-on-year increase compared to 2022 and brought the number of EVs on the world's roads to 40 million. The problem with this is that demand for batteries, and the materials required to make them, is soaring.

"One of the big challenges is that the minerals are kind of concentrated in certain places," says Christian Marston, president and chief operating officer of Altilium. Over half of the world's nickel comes from Indonesia, while two-thirds of all cobalt comes from the Democratic Republic of Congo – both of which have ongoing human rights issues associated with mining operations.

That's why there's now a race to find other ways of sourcing those key minerals. Recycling batteries is one option, but is also notoriously difficult. Staff at Altilium, however, say they've cracked it.

Altilium's facility is squirreled away in the unassuming English town of Tavistock. Getting here involves driving across the windswept expanse of Dartmoor, sometimes slowing to a crawl to wait for sheep to get off the road. When I arrive, I find Altilium's building on a mundane industrial estate with a tyre shop across the road – but what they're cooking up inside is anything but mundane.

In the lab I find racks of glass cylinders linked together by tubes, all filled with brightly coloured liquids – mostly vivid blues and greens – running the length of the room. Nearby, a technician wearing a white lab coat and safety glasses studies the workings of these contraptions.

This is Altilium's solvent extraction lab, where staff retrieve sought-after battery ingredients from the black mass they process here.

It all began in late 2020, but got off to a slow start. "We lost two years because of Covid," says Marston ruefully.

But in mid-2022, he and colleagues took out a lease on the Tavistock facility – at the time, an "empty shed", says chief technology officer Ben Wickham. The team built several laboratories, and began developing their recycling process on a small scale. Three years later, they are commissioning a larger plant just outside nearby Plymouth, which will supply recycled materials to battery manufacturers.

The company is one of just a handful of firms around the world that are developing methods for recycling batteries sourced from old EVs. Such firms promise to bring us one step closer to net-zero greenhouse gas emissions and also closer to a circular economy, in which almost nothing is thrown away.

"We have to remove that myth that batteries go to landfill," says Marston. As EVs have become more popular, more and more of them are now reaching........

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