Recycling tech for electric vehicle batteries

Making the most of the precious components used to make EV batteries
02 August 2021

Interview with 

Gavin Harper, University of Birmingham




Car batteries do eventually degrade and need to be replaced. They contain critical and rare materials which need to be recycled, and if we don’t recycle them, the environmental arguments for electric vehicles are undermined, so recycling is a major priority, but it’s also in its infancy, as Eva Higginbotham has been hearing from Gavin Harper from the University of Birmingham. Fully Charged's Robert Llewellyn also weighed in...

Eva - To try and understand the complex world of battery recycling I went to expert Gavin Harper from the University of Birmingham. And first things first, how long do these batteries actually last before they need to be replaced? Turns out that's hard to say.

Gavin - It's a how long is a piece of string question because there are different cathode materials, which is the active material in the battery, and obviously, there are different manufacturers, different formulations, different technologies.

Eva - There's also whether the battery has active or passive cooling, how you've treated the battery over time, and the technology is also continuously evolving and being upgraded. Car manufacturers though are currently offering warranties on their batteries for about eight years, which Gavin thinks seems to be a good design life for these batteries. And it's also worth considering that after the first life in an electric vehicle, the battery could be given a second life.

Gavin - For example, we could use that electric vehicle battery for stationary energy storage to support the grid or to provide backup power. So, you know, between the first life in a vehicle and a second life in a different application, you know, we can really squeeze the pips out of the technology

Eva - But for batteries that really have reached the end of the road and can't be reused or repurposed, there are a range of different recycling technologies being used and developed, the simplest being pyrometallurgy

Gavin - That is a process where the batteries are put into a pyrometallurgical smelter, it enables us to extract some of the valuable metals in the battery. So things like cobalt and nickel we can get very easily from that process.

Eva - One of the caveats though, of pyrometallurgy is that some of the battery components get consumed in the process while others end up in what's called a slag from which useful materials can be very difficult to recover. Another option, though, is hydrometallurgy, which uses liquid to leech out the active components, and here you get to use special shredders

Gavin - Rather than putting sheets of paper in we've got very big shredders with very big teeth.

Eva - These break the battery apart, but, as happens with shredders, what comes out is a lot of jumbled-up material. And it can then take a long time to pick out the bits you actually want for a new battery. The ideal, according to Gavin, would be Direct Recycling where the important and costly material that makes up the electrodes in the battery, the lithium or the cobalt for example, is cleanly separated out from the battery and rejuvenated, ready to be put back in. And there's lots of research going on at the moment to try and improve this technology. But we have to remember that before we can get to the point of recycling there's a lot of unseen steps. The battery has to be removed from the car unscrewed and everything disconnected safely and taken apart. And Gavin thinks that once we are recycling electric vehicle batteries at scale in the future, we're going to have to find a way of automating this process.

Gavin - There are some really interesting scientific challenges around how can you get robots and artificial intelligence to be able to perform some of these automated steps. And if you think about it, it's a much more complex challenge than manufacturing a battery with robots, because if you think about things on a production line, a robot just has to perform a very repetitive set of motions to produce a very uniform product. If you're processing batteries at the end of life, we've got such a fast array of different battery types from different manufacturers there's an awful lot of variety to contend with. And so if you're going to build a robot or an automated system to process those batteries, you're going to need an awful lot of flexibility, and you're gonna need a lot of intelligence in that robot. It can't just be a dumb robot that performs a repetitive series of actions.

Eva - So along with smarter, greener tech for our cars, we need smarter robots to be able to handle them. And although there are more sophisticated battery recycling facilities being developed in the UK and abroad, it seems the recycling industry is going to have to get into gear if we're to make the most of our electric car batteries in the future.

Chris - Gavin Harper, from the University of Birmingham, talking with Eva earlier. Robert, with your Scrapheap Challenge hat on, perhaps, what's your take on this?

Robert - You're absolutely right, we do need to be able to recycle them really well. I mean, it's a massive business opportunity. So one of the founders of Tesla in America, JB Straubel has formed a company called Redwood Materials, which is already operating. It's recycling thousands and thousands of tons of thrown away phones and laptops and tablets and all that stuff. And extracting huge amounts that are in the 90% of the material out of that. So it is already happening. There's a company in Germany we went to see on Fully Charged to do exactly the same thing. So of course it's got to happen and I just want to quickly remind our listeners that when was the last time you heard about someone recycling a litre of diesel?


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