Conventional ways of recycling lithium-ion batteries produce unwelcome byproducts, including carbon emissions. Now a company called Aqua Metals is betting on a new technique -- electro-hydrometallurgy -- that is run on clean, cheap renewable electricity. I get into the details with CEO Steve Cotton.
It was interesting for me to listen to this conversation, and I think there was some helpful information for listeners who are interested in the nuts and bolts of different recycling pathways and their associated challenges. The prospect of a waste-free recycling process is certainly exciting, and it's possible that Aqua Metals really is the "cleanest" of the available options-- I don't have the chemical engineering background to evaluate the claims different companies make about their processes.
That said, I often see companies in the battery and battery materials/recycling industry deploy "sustainability" as a way to pitch their technology and promote the problem they are supposedly solving compared to their competitors. I am pretty confident that you could interview the CEO of any of these new battery recycling companies, and they would all have their own answers about why their product is the most sustainable and cost-effective ever. They pretty much across the board claim to recover 95% of the critical minerals, use clean energy, etc. Hopefully all these claims are true, but I generally take anything early-stage companies say with a grain of salt and would be careful about how you broadcast their message, particularly when the message is that lithium-ion battery recycling is some exceptionally horrendous process.
I think it's worthwhile to note that every new facility that has been announced in North America in the last five or so years uses or plans to use some type of hydrometallurgical process, not pyrometallurgical, and while there are challenges regarding chemical use and solid waste, it's important to put this information in context. It is still lower-impact compared to mining new material for CO2 emissions, not to mention local impacts like habitat destruction, waste/tailings, water and soil degradation, and SOx emissions that are associated with mining nickel and cobalt and many other materials. It is also comparable to countless other industrial processes that we rely on and no one talks about.
I think it's very important to hold clean energy supply chains to a high standard and make them as circular and low-emissions as possible, but framing battery recycling as though it's a huge sustainability disaster is a) not that accurate or at least not proportional to the situation in my opinion and b) potentially harmful because it can be leveraged and contribute to anti-EV rhetoric unnecessarily.
Okay thanks for reading if you made it all the way to the end! I am a big fan of this podcast and in general I'm very stoked that you're digging into supply chains and recycling :)
From the article I am working on for a Who’s Who in LiB Recycling. The AQMS process in a nutshell
A slurry of black mass and H2SO4 is created and sent to a filter press, where the carbon is removed. Then the pH of the slurry is adjusted to precipitate the Fe, Al. Next, solvent extraction is used to separate the transition metals, Ni, Co, and Mn, from the pregnant leach solution (PLS). The leachate is then sent to membrane electrodialysis stacks, where the Li2SO4 is split to produce LiOH and regenerate the H2SO4. The LiOH is then sent to a crystallizer stage to be converted into Lithium Hydroxide Monohydrate (LiOH.H20). The transition metals are sent to an Electrowinning platform where they are deposited on plates to create ingots of Cobalt, Nickel, and Copper. The Manganese is plated as Manganese Dioxide in the same cell as the Cobalt.
Also a lot of what Steve was saying was fluff and referencing legacy process that beyond small municipal recyclers like in Finland and France no one still uses. Most of the larger companies like Umicore have moved onto electric arc style furnaces where volatiles in the LiBs including the plastics also assist in the heating. But they are not just chucked in, most do a size reduction and scrub not only for HF but VOCs as well. While not as possibly “green” as a low acid load hydrometallurgical platform, they are not the pollution spewing factories Steve described. If you want to see the stats on a domestic process the EA for Redwood materials is availed online.
If you want to know the current state of the LiB recycling industry, do not ask the CEO of a LiB recycling company.
With Johnson Controls on the investor list there is definitely a play for "supplying the equipment and machine parts for all metals recycling companies" as a business placement strategy, but I'd like to see more about how they feed into raw input materials for real companies with real input and impurity expectations. Apple, for the longest time, wouldn't even take the offcuts and trimmings from their own cases collected in their own factories as inputs into their own manufacturing process because their feedstock standards were challenging to meet if you didn't start with virgin material. That was just for mechanical components, nothing complicated like an electrochemically active component. In plastics you tend to see 9 parts virgin plastic for each part recycled plastic in a 'recycled plastic' material (using the broad version of recycled material definition because material is a mixture and not entirely virgin). In battery manufacture you have mechanical and electrochemical considerations and one battery's dopant is another battery's impurity. There is a general approach that produces a recovered output that ends up being useful to no one building a high performance product, and then the localized solution where every specific input and output chemistry becomes a puzzle of complex processing that is likely cheaper when starting from a known raw ore rather than a bunch of random compounds that are chemically similar to your target - but completely wrong for your purpose.
For a company that already pivoted from lead-acid to LFP, the controls path has to feel more comfortable than forever chasing the moving target of specific battery chemistry tolerances and requirements. And in that perspective, it isn't as important that they haven't figured out how to upcycle the carbon yet so long as they figured out how to build a system that could be used to upcycle carbon. In this frame your own facility supports your controls offering rather than a going business of recycling and upcycling.
But from a "can't we make this economy circular?" perspective, until the pace of development slows we're going to be churning through intermediary stages of battery performance and chemistry for a while and those last generation units are going to have the wrong compositions for next generation units. Aluminum recycling is a peak recycling scenario in part because the alloy series commonly used in canning was developed over 20 years starting in 1906, and as a mechanical product comprised of a metal alloy there is flexibility in the composition for the service expectations of canning and can manufacturing. Batteries have far more stringent requirements, in more dimensions, and we're still in the rapid evolution phase of compositions. It always strikes me as a bit of a red herring, it makes far more sense to ask about ICE ecosystem recycling; not only are those material demands more stable there are many more consumables to manage. Why apply this standard to the new thing and not the old thing it is meant to replace? If recycling was the moral driver of behavior that are usually held against the greener technologies we'd be lightweighting vehicles to avoid wear and tear on the tires, for instance, and that would benefit all modes of vehicle power at the same time (as well as our fish, air quality, and water supplies).
Hurrah for transcripts!!!
It was interesting for me to listen to this conversation, and I think there was some helpful information for listeners who are interested in the nuts and bolts of different recycling pathways and their associated challenges. The prospect of a waste-free recycling process is certainly exciting, and it's possible that Aqua Metals really is the "cleanest" of the available options-- I don't have the chemical engineering background to evaluate the claims different companies make about their processes.
That said, I often see companies in the battery and battery materials/recycling industry deploy "sustainability" as a way to pitch their technology and promote the problem they are supposedly solving compared to their competitors. I am pretty confident that you could interview the CEO of any of these new battery recycling companies, and they would all have their own answers about why their product is the most sustainable and cost-effective ever. They pretty much across the board claim to recover 95% of the critical minerals, use clean energy, etc. Hopefully all these claims are true, but I generally take anything early-stage companies say with a grain of salt and would be careful about how you broadcast their message, particularly when the message is that lithium-ion battery recycling is some exceptionally horrendous process.
I think it's worthwhile to note that every new facility that has been announced in North America in the last five or so years uses or plans to use some type of hydrometallurgical process, not pyrometallurgical, and while there are challenges regarding chemical use and solid waste, it's important to put this information in context. It is still lower-impact compared to mining new material for CO2 emissions, not to mention local impacts like habitat destruction, waste/tailings, water and soil degradation, and SOx emissions that are associated with mining nickel and cobalt and many other materials. It is also comparable to countless other industrial processes that we rely on and no one talks about.
I think it's very important to hold clean energy supply chains to a high standard and make them as circular and low-emissions as possible, but framing battery recycling as though it's a huge sustainability disaster is a) not that accurate or at least not proportional to the situation in my opinion and b) potentially harmful because it can be leveraged and contribute to anti-EV rhetoric unnecessarily.
Okay thanks for reading if you made it all the way to the end! I am a big fan of this podcast and in general I'm very stoked that you're digging into supply chains and recycling :)
From the article I am working on for a Who’s Who in LiB Recycling. The AQMS process in a nutshell
A slurry of black mass and H2SO4 is created and sent to a filter press, where the carbon is removed. Then the pH of the slurry is adjusted to precipitate the Fe, Al. Next, solvent extraction is used to separate the transition metals, Ni, Co, and Mn, from the pregnant leach solution (PLS). The leachate is then sent to membrane electrodialysis stacks, where the Li2SO4 is split to produce LiOH and regenerate the H2SO4. The LiOH is then sent to a crystallizer stage to be converted into Lithium Hydroxide Monohydrate (LiOH.H20). The transition metals are sent to an Electrowinning platform where they are deposited on plates to create ingots of Cobalt, Nickel, and Copper. The Manganese is plated as Manganese Dioxide in the same cell as the Cobalt.
Also a lot of what Steve was saying was fluff and referencing legacy process that beyond small municipal recyclers like in Finland and France no one still uses. Most of the larger companies like Umicore have moved onto electric arc style furnaces where volatiles in the LiBs including the plastics also assist in the heating. But they are not just chucked in, most do a size reduction and scrub not only for HF but VOCs as well. While not as possibly “green” as a low acid load hydrometallurgical platform, they are not the pollution spewing factories Steve described. If you want to see the stats on a domestic process the EA for Redwood materials is availed online.
If you want to know the current state of the LiB recycling industry, do not ask the CEO of a LiB recycling company.
With Johnson Controls on the investor list there is definitely a play for "supplying the equipment and machine parts for all metals recycling companies" as a business placement strategy, but I'd like to see more about how they feed into raw input materials for real companies with real input and impurity expectations. Apple, for the longest time, wouldn't even take the offcuts and trimmings from their own cases collected in their own factories as inputs into their own manufacturing process because their feedstock standards were challenging to meet if you didn't start with virgin material. That was just for mechanical components, nothing complicated like an electrochemically active component. In plastics you tend to see 9 parts virgin plastic for each part recycled plastic in a 'recycled plastic' material (using the broad version of recycled material definition because material is a mixture and not entirely virgin). In battery manufacture you have mechanical and electrochemical considerations and one battery's dopant is another battery's impurity. There is a general approach that produces a recovered output that ends up being useful to no one building a high performance product, and then the localized solution where every specific input and output chemistry becomes a puzzle of complex processing that is likely cheaper when starting from a known raw ore rather than a bunch of random compounds that are chemically similar to your target - but completely wrong for your purpose.
For a company that already pivoted from lead-acid to LFP, the controls path has to feel more comfortable than forever chasing the moving target of specific battery chemistry tolerances and requirements. And in that perspective, it isn't as important that they haven't figured out how to upcycle the carbon yet so long as they figured out how to build a system that could be used to upcycle carbon. In this frame your own facility supports your controls offering rather than a going business of recycling and upcycling.
But from a "can't we make this economy circular?" perspective, until the pace of development slows we're going to be churning through intermediary stages of battery performance and chemistry for a while and those last generation units are going to have the wrong compositions for next generation units. Aluminum recycling is a peak recycling scenario in part because the alloy series commonly used in canning was developed over 20 years starting in 1906, and as a mechanical product comprised of a metal alloy there is flexibility in the composition for the service expectations of canning and can manufacturing. Batteries have far more stringent requirements, in more dimensions, and we're still in the rapid evolution phase of compositions. It always strikes me as a bit of a red herring, it makes far more sense to ask about ICE ecosystem recycling; not only are those material demands more stable there are many more consumables to manage. Why apply this standard to the new thing and not the old thing it is meant to replace? If recycling was the moral driver of behavior that are usually held against the greener technologies we'd be lightweighting vehicles to avoid wear and tear on the tires, for instance, and that would benefit all modes of vehicle power at the same time (as well as our fish, air quality, and water supplies).