Farid Ahmed, VP of global strategy and business development at Ace Green Recycling sets out the thinking behind the company’s recycling of lithium-ion and lead batteries.
It makes no sense to extract a critical mineral, use it once and then stick it back in the ground as furnace slag. Indeed, it would appear to be irresponsible, a type of madness, to do that with a finite resource that could – and should – be recycled an infinite number of times in a way that is economically viable and with a lower environmental impact than just repeated digging some up and then dumping it. But this is happening with lithium in the recycling of lithium-ion batteries.
These ethical, moral and commercial imperatives were the key drivers for Ace Green Recycling – we could see how we could make a significant positive impact on this situation. We developed technology for sustainable and commercially viable scrap lithium-ion battery treatment, a process that grew from the principles of our groundbreaking lead recycling technology.
Both recycling processes are hydrometallurgical, are fully electrically powered and have zero Scope 1 carbon emissions. Where possible, we also try to marry this to renewable energy generation to power the plant for zero Scope 2 carbon emissions.
There are other key differentials for Ace’s lithium-ion recycling technology. It is chemistry agnostic, in that it can treat a variety of different lithium-ion battery chemistries simultaneously without the need to segregate battery types. However, we would always recommend separating the lower value LFP feed from nickel- and cobalt-rich scrap, so as not to dilute the high value metal stream. The LFP process is a subset of the NMC process flowsheet. That is just common sense.
The process is modular with increased capacity achieved by adding additional modules, not by building bigger ones. This means that installed capacity can exactly match the volume of available feed, thereby reducing the initial capital requirement to build a facility. Future expansion needs are met by simply installing more of the same modules. Contrast this to traditional pyrometallurgical facilities, which have a minimum feasible size for economic and operational viability. This generally results in inefficient running of the plant at well below capacity for years, with a very high initial capex, until sufficient feedstock becomes available.
The chemical flexibility of the process gives a level of future-proofing too. No one knows for sure which lithium-ion chemistries will dominate in future and the market split between them. However, at Ace, we rest assured that our process can adapt to cope with all of these.
We have also focused on economic recovery of other battery components, not just the CAM materials. We have a research collaboration with the National Renewable Energy Laboratory in the US, a federally funded R&D centre, to improve the sustainability and profitability of recycling LFP batteries, which includes enhanced recovery of graphite with preservation of morphology. Copper and aluminium electrode materials are transformed into payable by-products rather than a low-value mess of finely mixed metallic particles.
The importance of these developments could be considerable. Unlike batteries containing nickel and cobalt, the ‘F’ and ‘P’ (iron and phosphate) are worth very little. This really impacts the value chain of LFP recycling, and even more so for processes that cannot recover the ‘L’ – lithium.
Currently, in many regions globally, the holder of spent LFP is obliged to recycle it, but the value of this scrap is less than the cost to recycle. Treating this material can only be achieved by the recycler charging a fee to the producer of that scrap for reprocessing it. Long term, that is not a model which will guarantee high LFP recycling rates and return critical minerals into the supply chain. At Ace, we are working hard to make this process self-sustaining, which will only increase in importance with LFP becoming a far larger proportion of total lithium-ion output than most expected just a few years ago.
Unlike so many of the competing hydromet processes, for over a year we have been operating our own facility in India, where most of our operational, engineering and R&D resource is located. One can walk around our factory to see it for yourself. Contrast this with those CGI mock-ups and fly-through videos that other players in this sector present on their websites, depicting what it might be like, if and when they actually build their plants. We are doing it, right now, and on a commercial scale.
Ace has also developed improved battery discharging systems to increase the safety of battery breaking. Most readers will be aware that shredding lithium-ion batteries with more than a very small amount of charge can result in fires and explosions – far more excitement and danger than anyone needs in a recycling plant.
For large format batteries, we have produced dedicated cell diagnostics to determine the state of health to see if a battery might qualify for second life reuse.
The small format batteries (from laptops, phones, power tools, etc) are made safe by discharging in a special, non-saline solution. This avoids corrosion of the aluminium cell electrodes common with saline discharging, which can then lead to electrolyte leakage. These electrolytes are pretty nasty, so disposal of contaminated discharging solution then becomes a real headache. Our process avoids this problem.
What we have tried to achieve and, we think, succeeded at, is to create a holistic, efficient, sustainable and economically viable lithium-ion battery recycling technology covering a continuous path in the supply chain from spent battery to metal compounds ready for reprocessing into new battery raw materials. This gives an incredible sense of purpose to the work we do at Ace Green Recycling.
