Brought to you by Claude Chanson from RECHARGE the Advanced Rechargeable and Lithium Batteries Association in Europe
A simple concept: recycling efficiency
Batteries, and particularly lithium batteries for electric vehicles (EV) are complex products, containing critical raw materials in mechanical and chemical components, as well as electronics and plastics. So, depending on which materials we aim to recover, multiple processes may need to be applied.
The EU Batteries regulation recognised the importance of critical raw materials such a cobalt or lithium and proposed specific targets to promote the recovery of materials: one of these criteria is called “recycling efficiency” (RE) and is defined as the ratio of the weight of recycled materials (output fraction) versus the weight of waste battery (input fraction). It is calculated simply as Recycling Efficiency (%) = Output fraction/input fraction.
Of course, the more materials that are recovered, the higher this ratio is: the regulation sets a minimum of 65% for all lithium-ion batteries.
Economic benefit is the usual industry driver for investment in recycling processes, but the EU regulation’s additional target for RE is aiming at a different objective: to maximise materials recovery, particularly of critical raw materials. It is a topic of interest for the FutuRaM project to understand where and how the economic feasibility can be combined with sustainability expectations in the case of batteries, but also for setting potential targets for the RE of any complex product.
Practical calculation of the recycling efficiency
It appears that the achievement of the ambitious EU battery recycling targets (material recovery rate and recycling efficiency) at times conflict with each other, or with other environmental objectives, such as the minimisation of our carbon footprint.
The unique target for lithium-based batteries is causing technical difficulties as not all batteries contain the same chemicals. Thus, the target can be achieved for many but not all lithium batteries technologies when using industrial recycling processes.
The Batteries regulation, did not address this issue specifically, however it is recognised that the calculation methodology should not come with excessive environmental or economic cost while achieving the legal target for all commercial technologies. The discussion on the technical method1 (to be published in a Commission delegated act) can possibly introduce the required flexibility in the practical calculation.
The Commission’s approach for this delegated act is based on the exclusion of a list of elements from the calculation method (so called “negative list method“, NLM). For example, in the NLM, oxygen can be excluded from the weight of the recycled materials, as well as from the weight of the waste battery. Removing oxygen from the list is considered acceptable since recycling it offers no environmental benefit. In practice, it exempts oxygen from needing to be recovered. This can help some battery types meet the 65% legal target. The general mechanism can be easily understood by the following example:
Example 1: a battery that contains 20% of oxygen, 55% of recoverable materials and 25% of non-recoverable materials in the current recycling processes, assuming that there is no oxygen in the recovered material (i.e. this is the case for recycled metals). The calculation of the recycling efficiency is then:
- in the initial method: Input fraction = 100, output fraction = 55, and 55/100 = 55% RE. The legal target is not achieved.
- in the NLM method: Input fraction 100-20= 80 (oxygen is removed), output fraction = 55 (no oxygen content) and 55 / 80 = 69% RE. The legal target is achieved.
The numerical examples proposed here are only for explanatory purposes and are not intended to represent any specific composition or recycling process.
Oxygen is not a major concern, but the discussion may be more challenging for other materials. This is the case, for example, for the graphite particles used in lithium batteries anodes. Natural graphite is listed as a critical raw material. Currently, there is no available industrial process to recover this graphite into a material re-usable for batteries. It may be simply recovered as carbon. Similarly to oxygen, there is no environmental benefit in creating recycled materials such as carbon, and certainly not in combination with oxygen through CO2 emissions! This question is critical for a largely used composition called lithium iron-phosphate (LFP) that cannot achieve the legal RE target of 65% if the graphite is not included in the NLM.
When a simple concept becomes a complicated method
The concern is that the inclusion of graphite in the NLM would enable achieving the legal target for LFP recycled using the best industrial recycling techniques available today, but might also discourage the development of new technologies recovering graphite in the future: if carbon is included in the NLM, the benefits of graphite recycling and increased RE will be lost because it will be excluded from the calculations.
This issue of carbon discussed here is also applicable to other materials contained in some lithium batteries, such a sulphur, chlorine, and others.
In practice, this could result in an extensive list of materials exempt from recycling, which might be problematic. In addition, the NLM method is not promoting the development of new battery compositions containing less critical materials, and materials with less environmental impacts. Indeed, if the NLM does not identify these materials, it would be mandatory to recycle them even if it offers no environmental benefit (or the recycling process has negative environmental impacts) to meet the minimum legal requirement. The management of an NLM would then require regular updates which could be very problematic for industry visibility.
Use the market dynamics to drive a complex method toward optimisation
An alternative method is proposed to the Commission, called the “positive list method” (PLM). This method suggests identifying materials that must be included in the RE calculation, rather than listing those that are excluded, as the NLM does.
The advantage is that the minimum list of materials needing recycling can be created based on the knowledge of the existing compositions and industrial recycling processes. This list encourages battery designers and recyclers to develop innovative and potentially proprietary recycling techniques to improve the result of the calculated RE.
This can be illustrated with the following example:
Example 2: a battery that contains 20% of oxygen, 35% of recoverable materials (with no oxygen content) and 45% of non-recoverable materials in current recycling processes. Additionally, we assume that the non-recoverable material contains 20% graphite. This graphite was initially excluded from the input and output fractions in the NLM. It can now be included in the PLM when a new process enables recovering 90% of the 20% graphite, which represents 18%. In this case, the calculation of the recycling efficiency looks as follows:
- in the initial concept: 35 / 100 = 35% RE. The legal target is not achieved.
- in the NLM method: oxygen and graphite are removed from the input fraction (100-20-20= 60) and from the output fraction (35). Consequently, the RE becomes 35/60 = 58% RE. The legal target is not achieved and cannot be improved as the graphite cannot be accounted for.
- in the PLM method, the recovered graphite is added to the list of the output fractions (35+18 = 53), and equally included in the recyclable material list used for the input fraction (assumed to contain all materials except oxygen 100-20= 80). The RE becomes 53/80= 66% RE. The benefit of recycling graphite or any new material becomes apparent as soon as a new process is developed, without being hindered by a list of exclusions.
Note: the numerical examples proposed here are only for explanatory purposes and are not intended to represent any specific composition or recycling process.
If necessary, the PLM can later be expanded to include new compositions or recycling technologies as they become available for industrial use.
The Commission raised concerns about the apparent lack of control over the method, as recyclers developing any new recycling process with a new substance recovery could immediately introduce it in their RE calculations to boost their results.
RECHARGE believe that this concern should not prevent the introduction of this concept, as battery recycling is subject to declaration and verification. On the contrary, this approach is the right way to encourage innovation by allowing improvements to be implemented at the industrial level without needing to predefine or wait for updates to delegated acts. The minimum requirements for recycling can still be included in this approach and applied to a positive list of material where 65% recovery on average is reasonable. This way, the requirement is applied to a defined list of materials, avoiding technical feasibility issues and economic or environmental contradictions.
Conclusion
What seems like a simple concept can quickly turn into a complex and technical issue.
In such cases, the regulation could become a limitation rather than an incentive for a more environmentally friendly and competitive approach. A more flexible, environmentally focused method, known as the “positive list,” is proposed to guide battery recycling towards processes that optimise both economic and environmental outcomes.
This analysis also shows that the method for setting sustainability targets, such as recycling efficiency targets, must be carefully examined to truly fulfil its purpose: promoting and incentivising continuous improvement in the circular economy.
For the FutuRaM project, it is of key importance to define balanced rules for recycling, leading to accurate predictions of recoverable materials.
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1 JRC technical suggestions for the rules for calculation and verification of rates for recycling efficiency and recovery of materials of waste batteries. March 2023.
RECHARGE is the European industry association for advanced rechargeable and lithium batteries. Founded in 1998, it is our mission to promote advanced rechargeable batteries as a key technology that will contribute to a more empowered, sustainable and circular economy by enabling decarbonised electricity and mobility, and cutting-edge consumer products. RECHARGE’s unique membership covers all aspects of the advanced rechargeable battery value chain: From suppliers of primary and secondary raw materials, to battery and original equipment manufacturers (OEMs), to logistic partners and battery recyclers. www.rechargebatteries.org
Contact: Kinga Timaru-Kast, Public Affairs & Communications Director, ktimaru-Kast@rechargebatteries.org, +32 486 996 870