Recycling EV batteries

03 March 2020

Interview with 

Dr Gavin Harper, Birmingham University

RECYCLE-BIN

A cartoon of a recycling bin.

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How can the batteries inside electric cars be recycled, once they reach end of life? We need to plan for this, because the industry will struggle to continue to source the materials needed to make new cars and batteries if we haven’t got a way to supplement supplies of raw materials. Megan McGregor spoke to Birmingham University’s Gavin Harper about the way forward...

Gavin - If you take a battery and you were able to slice it apart very carefully without contaminating the materials in the battery, and if you were able to scrape off the cathode material from the electrode, and then you might apply some processes to improve its quality, and then coat that material straight into a new battery, that is direct recycling. And the benefit of that process is that it's not just about recovering the raw materials that go into the battery, it's also about preserving the structure in the cathode materials. And obviously a lot of energy, a lot of effort, goes into creating that structure of the cathode material.

Megan - It seems to me to assume that the battery chemistry will stay fairly constant. Are the recycling possibilities if down the line the battery chemistry changes? So for example, the amount of a material that's required goes up or down?

Gavin - I think the main challenge at the moment is around cobalt. Batteries with high cobalt content are very energy dense, which is good from the perspective that it gives the electric vehicles a really good range. The challenges around sourcing cobalt mean that there's a real push to try and reduce its use in electric vehicle batteries. Cobalt largely comes from the Democratic Republic of Congo. The conditions in which it's mined would cause a lot of concern. Children that are working in mining and the sort of unregulated industry that runs alongside of the sort of mainstream mining industry. There's work that's ongoing at the moment to look at, first of all, if you've got for example, a range of different cobalt chemistries and you've mixed everything together, how can you segregate those different cathode materials in a direct recycling process? So that is step one. And then secondly, there's work ongoing to look at if you've got chemistry of one cobalt formulation, can you reformulate that into a different battery chemistry by adjusting the mix? And I think they're both really interesting avenues of exploration for direct recycling.

Megan - And is it possible in future that if we manage to reduce the cobalt concentration in future batteries, that it may become desirable to recycle the batteries of today more immediately, because of their high cobalt concentrations?

Gavin - Yeah. So I think there's a real tension between recycling and reuse. And if we think about how the market for recycled batteries might operate, if a battery comes out of a car and it's still got useful life in it, then that has an economic value. And so our normal approach would be to reuse that battery and extract the most life out of it, you know, squeeze the pips out of it as it were. However, you could imagine a situation in the future where the supply of cobalt was constrained, either because of the supply chain or processing capability or the mining. And in that situation it might be advantageous to recycle batteries early that are of a high cobalt chemistry. If you had a technique whereby you could produce more batteries with a lower cobalt chemistry from the same resource, I think you can look at what's optimum from a resource allocation and resource efficiency angle. But then that's obviously going to run into the buffer of real world economics.

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