The challenge with closing the loop in lithium-ion battery recycling
Martin Steinbild, managing director for Steinbild Consulting, shares his insights into the challenges to closing the loop in lithium-ion battery recycling, as well as the strategic aspects to this industry that market participants should be aware of.
- Recycling material reduces the amount of raw material extraction
- Recycling reduces the environmental footprint, water usage and emissions compared to raw material production
- It reduces the raw material dependency of Europe.
In this article, Martin looks more closely at the recycling process and strategic aspects to the industry.
Recycling process overview
Rockwood Lithium, which is now Albemarle, started with industrial and university partners an electric vehicle (EV) battery recycling project in 2009 called LithoRec. I had the honour to lead and coordinate this project. The LithoRec process forms the base for most of the recycling processes discussed today. Competing pyrometallurgical processes typically are focused on the recovery of transition metals only, suffering on poor recycling efficiencies, on a worse life cycle balance and on higher costs.
At the beginning, some form of sorting batteries by battery chemistry is necessary. With the introduction of a battery pass and QR code, demanded by EU authorities, this will not be an issue anymore.
The typical recycling process includes discharging the EV battery to handle all following work steps safely. Energy can be used in the recycling factory.
The next step is dismantling the EV battery. LithoRec showed that robot-assisted dismantling in a human-machine interaction environment is possible, but the issue is the non-standardization of batteries, impeding automation. To improve the economics of the recycling processes, reducing human labor intensity in dismantling is extremely beneficial.
These modules will undertake a shredding process under inert gas or in a fluid. The fluorine-containing electrolyte will be deliberated and can be recovered in the inert gas process, although reaching quality and purity requirements are really challenging. Shredding under water causes problems of water purification, potentially could lead to still reactive black mass and prohibits the recovery of the electrolyte.
Following mechanical sorting and classification processes effectively separate the copper and aluminium foils from the black mass, which consists of the active anode and cathode materials.
As transport of batteries, modules and cells, especially if damaged, is highly regulated and potentially risky, the above-described recycling steps should be performed locally. Black mass is a powder and can be easily transported. So, it makes sense to have several black-mass producing sites feeding a centralised hydrometallurgical recycling plant.
Typical hydrometallurgical processes dissolve the black mass, using strong acids, like sulphuric acid assisted by hydrogen peroxide. Graphite will not be dissolved and swims on top of the solution and can be removed, easily. The complete removal of fluorine containing substances in the previous steps is crucial to prevent HF formation.
From my point of view, the hydrometallurgical part of the recycling process is most challenging. One problem is the non-uniform composition of black mass. Every battery manufacturer has its own battery chemistry and, depending on battery usage history, several different degraded chemicals will be present. Therefore, the hydro-process must be very robust.
Even with intense efforts, reaching battery grade qualification is at least a challenge if economically possible at all. But many recycling process developers claim exactly this, that they can reach battery-grade specifications with their recycled products. This raises the obvious question, why is lithium not recycled into new batteries up to now? Bench-scale results under optimum conditions are simply not relevant for recycling in industrial scale.
Strategic aspects to battery recycling
Battery raw materials are either available from end-of-life (EOL) batteries after use, or from battery production waste. The reject rate in battery manufacturing plants is high, especially during ramp-up phases of new facilities and the reject rate is higher for EV batteries compared to portables. The total reject rate by weight can be in the range of up to 30% at the beginning of production.
New discussions in the industry indicate a general reduction of the waste range from battery manufacturing in the future as battery companies increase the degree of automation and constantly improve the processes.
Many battery manufacturers incorporate recycling processes into their battery plants. On the one hand, it is easier to recycle from production waste, as the recycling input streams are clearly defined (i.e., known and not much varying). On the other hand, recycling is more complex, as waste from different stages of the production process needs to be handled. Optimization of recycling processes for every single waste stream is most likely not possible. The nature of active material slurry waste makes it suitable for a distinct recycling loop. Because of purity of battery production scrap, it could be easier to reach battery grade quality compared to EOL-battery recycling.
A fundamental question for recycling companies, eager to enter the market, is the availability of batteries and access to batteries and battery scrap. In case of inhouse recycling or contract-based recycling of battery production scrap, the material will not be available for 3rd parties.
When it comes to EOL batteries, the producer (in case of EV batteries, the car manufacturer (OEM)) is responsible for recycling within the EU. OEMs are key as they will have access to most of the EOL-batteries through partner or company service and repair shops. Extremely important will be, if battery recycling is a business, or is at cost.
Because of the lack of valuable metals, it is likely that LFP or LMFP battery recycling will be at cost. In this case the battery owner (OEM) has to pay for recycling. If recycling is a business, then the recycler pays to the OEM for the battery.
Will it be an ideal market only based on supply/demand and prices? Or will there be structures based on long-term contracts between recyclers and OEMs? I assume, that because of the sheer battery volumes owned by OEMs and availability in different regions worldwide, most of the material will be traded on a long-term contract base between OEMs and a handful of global recyclers.
Join Martin at European Battery Raw Materials Conference 2022
On day one of this year’s European Battery Raw Materials conference, Martin will be moderating a fascinating panel discussion on establishing close loop EV battery recycling. He’ll be joined by Dr Vipin Tyagi from ACE Green Recycling, Megan O’Connor from Nth Cycle, Michael Insulan from Commercial Electra and Hans Eric Melin from Circular Energy Storage.
The panel will cover questions including:
- How much of BRMs can be recuperated from recycling, including the potential for mining waste and failed battery cells?
- Can LFP be economically recycled?
- Black mass processing: Can it be a profitable operation?
- When can we expect to reach the scale of Chinese capacity for black mass treatment?