Faced with the autonomy or the price of electric cars, the question of recycling batteries seems anecdotal to say the least. However, the subject is central for more than one reason, whether to reduce the environmental footprint of electric vehicles or to limit the cost of end-of-life batteries.
Once their storage capacity is no longer sufficient to power electric vehicles (EV), what happens to the used batteries? Few motorists wonder about the subject, preferring to leave it to the manufacturers. Yes, but here it is: the recycling and reuse of batteries is an essential step in the life cycle of EVs and, in fine, have consequences for the development of technology, a significant ecological impact and repercussions for the individual.
The many challenges of battery recycling
Between regulatory obligations, reduction of the environmental footprint and economic viability, the recycling of electric car batteries is faced with all kinds of requirements. However, the operation seems – for the moment – difficult to answer.
An essential lever to reduce the footprint of EVs
The main interest of the electric car – and which motivates its democratization around the world – is a lower environmental impact than its thermal counterpart, at least for use. Including energy production, an EV would release almost 8 times less CO2 than an equivalent thermal vehicle in use, mainly due to the absence of polluting emissions(1). A largely positive assessment that should however be nuanced, since the electric car sins at several other stages of its life cycle:
- Electricity production, still mostly carried out via coal or nuclear power plants (variable depending on the country);
- The manufacture of the lithium-ion battery, whose environmental cost for the extraction of ores is colossal;
- Battery recycling, a technically and legally upgradeable item.
According to various studies, sometimes contradictory, it would be necessary to travel between 25,000 and 150,000 kilometers(2) (3) – mainly depending on the energy mix of the country analyzed – before the electric car becomes less polluting than diesel or equivalent petrol. While the truth is probably in between these two numbers, it illustrates how EVs aren't as "green" as it sounds.
To reduce the overall ecological footprint of the electric car, the first solution could therefore be to intervene in energy production, via the gradual abandonment of fossil fuels and nuclear power, in favor of renewable energies (solar, wind, etc.). A project which is certainly commendable, but which is struggling to impose itself in most countries, mainly because of important economic issues. The second possibility would be to make the extraction of raw materials more virtuous. However, at present, no viable process seems to be able to replace the techniques used, the latter requiring significant amounts of energy and water, in addition to contaminating the soil.
Faced with this double impasse, only one path seems to be usable in the immediate future and is concentrating more and more attention: recycling the battery.
Regulation still too undemanding
However, we would be wrong to think that manufacturers are interested in recycling the electric car battery by simple kindness. They are in fact bound by the principle of “Extended Producer Responsibility” (EPR), making them responsible for the entire life cycle of the products they market, particularly with regard to the treatment of waste. More specifically, Directive 2006/66 / EC adopted by the European Parliament in 2006 provides that “ producers of batteries and accumulators and producers of other products in which a battery or accumulator is incorporated are responsible for the management of the waste batteries and accumulators which they place on the market " In practice, manufacturers therefore have an obligation to ensure that there is a collection and recycling system which they can use, in particular for batteries, before marketing a vehicle.(4).
Despite everything, the regulations still seem very light in the face of the issues at stake. It must be said that manufacturers are only required to recycle 50% of the average weight " other waste batteries and accumulators », A category which includes lithium-ion batteries. For comparison, European regulations impose a minimum recycling of up to 65% for lead-acid batteries – used by thermal vehicles – and even 75% for nickel-cadmium accumulators, mainly used for industrial purposes.(4). This regulation is all the more perfectible as certain rare or precious materials – such as lithium for example – are extremely light. The advantage of recovering them, when it is above all necessary to recycle 50% of the weight of the battery, may therefore seem limited for manufacturers.
A volume of waste that risks exploding
At present, these low recycling quotas have a still limited environmental impact, since the volumes to be treated are relatively small. During a hearing in the Senate in the summer of 2019, Christel Bories, then president of the Strategic Committee of the Mining and Metallurgy Sector, indicated that the recycling of electric car batteries represented, for the moment, only 15,000 tonnes of waste per year. But given the expected boom in EVs, this volume could be multiplied by 3 by 2027, or even by almost 50 by 2035, and this, reaching a total of 700,000 tonnes each year.(1). Some studies, even more confident in the development of the electric car, even suggest that the batteries to be recycled will already represent 2 million tonnes per year from 2030(5). Everything will certainly depend on the involvement of the public authorities in the development of the sector, but also on the state of the second-hand electric car market, the latter possibly making it possible to extend the recycling deadline.
Faced with such forecasts, improving recycling – both from a technical and regulatory point of view – seems essential, even urgent. Why ? Quite simply because it is legitimate to question the fate of waste that is not recycled, whether due to technological constraints or a lack of will on the part of manufacturers. According to Frédéric Salin, the commercial marketing director of SNAM – the main player in the collection and recycling in Europe of electric car batteries – everything that is not recycled ends up being destroyed, burned, and finally buried for 2% of the original tonnage(1). Without redesigning the current system, this could represent up to 14,000 tonnes of buried waste each year by 2035.
Battery recycling, a perfectible sector
More than ever, recycling appears to be an inseparable stage in the life cycle of electric car batteries. But despite the regulations and the involvement of many players, the operation still seems to face many limits, both from a technical and economic point of view.
Everyone has their own recycling method
Although the recycling methods vary according to the battery technology and the players, the operation most often begins with the discharge of the residual energy still present – this can even be used to power other equipment -, followed by the disassembly of the components. The main objective is to isolate the hundreds of lithium-ion cells that make up the battery, in particular electronic parts. The plastic and metal elements, as well as the structure of the battery are sorted, before being redirected to specific recycling channels.
Then comes the most complex step: the separation of the chemical components at the heart of the battery, including lithium, cobalt, manganese, nickel or even rare earths (cerium, lanthanum, neodymium, etc.). There are currently two different methods of doing this.
- Pyrometallurgical recycling : this technique is based on gas-heated pyrolysis ovens, which allow the organic matter to be brought to very high temperature in order to destroy it and capture the polluting elements contained within the cells. The metals can thus be separated according to their melting temperature. They are then placed in a specific solution to dissociate the chemical elements (lithium, nickel, rare earths, etc.) and to purify them.
- Mechanical recycling : the method consists in grinding the cells, before recovering the electrolyte (liquid allowing the circulation of ions) by evaporation and purifying it by condensation. Unlike the thermal process, the electrolyte can thus be reused for new batteries. Once separated from the ionic solution, the metals that make up the electrodes – such as lithium, cobalt or manganese – can then be more easily sorted. For this, it is processes such as gravimetric (depending on the density of materials) or magnetic (depending on the behavior of each material facing a magnetic field) that are used.
It is this second technique which seems to be the most efficient for the moment, for several reasons: it would consume around 70% less energy, it would release less CO2 and it could – in theory – recover up to 85% of the weight of used batteries(6) and up to 91% for the materials making up the cells (compared to just over 30% for the pyrometallurgical processes)(7). Unlike thermal recycling, which is particularly energy intensive and emits a lot of CO2 due to the use of gas, mechanical recycling would differ on another point: the metals and components thus recovered would allow the manufacture of new batteries to generate less greenhouse gases than when assembled with new materials.
Many actors, differing results
The figures previously put forward are, however, to be taken with caution. Indeed, the recycling industry of electric car batteries sometimes lacks transparency, while its actors multiply the announcements to extol the merits of their processes.
Recycling by mechanical method – the results of which appear to be the most convincing – is still a relatively recent technique. Particularly used by the German company Duesenfeld, it does not seem for the moment to have been officially adopted by European manufacturers. On the other hand, many of them have joined the SNAM (Société Nouvelle d'Affinage des Métaux) industry – such as Peugeot, Toyota and Honda(8) – whose recycling technique is mainly based on the thermal method. The tri-color company, for its part, claims to recycle 70% of the weight of lithium-ion batteries(1).
Other actors are also involved on the subject. While Renault is betting on the Euro Dieuze company, Nissan trusts Recupyl. However, neither of the two manufacturers really communicates on the results obtained. Unlike Volkswagen, which manages the recycling of batteries for its electric vehicles, in a center located in Salzgitter. According to the manufacturer, the site would recycle 1,200 tonnes of battery per year with, for the moment, a recycling rate of 53%. A result that the German intends to advance up to 72% in the medium term, then up to 97% by perfecting the techniques used(9).
This overview of recycling players could not be complete without mentioning the ReLieVe (Recycling Li-ion batteries for electric Vehicle) project, developed by Suez, Eramet and BASF. Started in January, this program subsidized by the European Union has a clear objective: to be able to recycle lithium-ion batteries 100% by 2025(10). For this, the idea is to work in a closed loop and to recycle metals without modifying their physical and chemical qualities. The objective? Do not lose anything during the process and minimize the carbon impact of recycling, which is very high via the pyrometallurgical method. However, it is difficult to have more information on the technique used at the moment.
Far from profitable
Whatever the technique used or the actors involved in the subject, recycling batteries continues to pose another problem: it seems difficult to economically viable. According to SNAM, the sector is not profitable at present, mainly due to a processing volume still limited compared to the investments required. If companies generally remunerate themselves with recycled metals which they can then resell, the balance still does not seem to have been reached, in particular because the price of materials is sometimes down. To alleviate the problem, SNAM has – as an example – provided with Honda that the manufacturer pays him a cash payment when the value of the materials does not cover the cost of recycling. An agreement that we imagine difficult to keep in the long term.
However, the situation could quickly change – provided that the lithium-ion technology is retained – as demand seems to explode in the years to come. According to the scenarios considered the most optimistic, electric vehicles could represent a third of the world automobile market from 2025 and 70% by 2050. Consequences? The needs of manufacturers, in lithium alone, could be 3 to 7 times greater than they are today. And this is where recycling shows its interest(11).
In addition to being still rudimentary, the conventional extraction process would currently allow only 40 to 50% of the lithium contained in brines to be recovered (a saline solution containing in particular this chemical element). While it takes "only" 28 tonnes of lithium-ion batteries to obtain 1 tonne of lithium, it takes 750 tonnes of brine to have the same amount(11). What strengthen the economic interest of recycling but, once again, provided that the global automotive market is electrified quickly.
Second life, an alternative to recycling
Faced with the problems encountered by the recycling industry, manufacturers are beginning to understand that they must extend the lifespan of electric car batteries as much as possible. How? 'Or' What ? By using them for other uses as soon as their capacity is no longer sufficient for vehicles.
A solution to extend battery life by 10 years
Most manufacturers consider that the lifespan of an electric car battery is between 1000 and 1500 charge-discharge cycles. Beyond that, the storage capacity is generally only 70 to 80% of what it was originally. As the level of performance is no longer considered sufficient, in particular since it considerably limits the vehicle's autonomy, replacement of the battery becomes necessary.
But rather than directly recycling it in order to extract the maximum of elements, the choice is more and more often made to exploit all the remaining potential by other means. If it is not powerful enough for mobile use, the used battery – retaining a storage capacity of 70 to 80% – remains entirely suitable for stationary use. Enough to extend their lifespan up to 10 more years for the least demanding uses and, thus, reduce the overall pollution generated by the batteries.
Still too few initiatives
Although the reuse of batteries seems to be a relevant solution to reduce their environmental and economic cost, so-called "second life" projects are still few.
Nissan and special stationary storage
Nissan seems to be the most advanced manufacturer on the question of the second life of batteries. In partnership with Eaton, it has developed equipment called xStorage Home, which can be controlled from a smartphone. This relies on used batteries to create an electricity storage device for individuals. If the accommodation produces its own renewable energy, in particular by means of solar panels, the system will recharge, then making it possible to redistribute the electricity thus stored when the accommodation needs it or to resell it to the network. In the absence of photovoltaic panels, xStorage Home nevertheless has an advantage: it allows electricity to be stored during off-peak hours, before redistributing it during peak hours.
Second life, a major subject for Renault
For Renault, the issue of recycling and reusing batteries is also central, since 80% of them are rented and their replacement is therefore only rarely at the driver's expense. In addition to a solution similar to xStorage Home, the French manufacturer reuses used batteries to transform them into charging stations, but also into an emergency storage system – in the event of a power cut, for example. This second solution is also already in place at the Dutch soccer stadium Johan Cruyff Arena, while awaiting the possible creation of an electricity storage plant that could supply no less than 120,000 homes , always with used batteries.
A second life facing major challenges
With the exception of Nissan and Renault, initiatives to reuse electric car batteries are almost non-existent. An astonishing observation when we know that the cost of energy storage can be up to 2 times cheaper with recycled batteries than with specific new batteries (12). By 2025, the gap could even be increased to 70%(13).
A question therefore arises: why reuse does not seem to be unanimous among manufacturers and manufacturers of batteries? Simply because there are still (too) many barriers to overcome for this.
- Technological disparity : for the same manufacturer, the batteries used may vary from one model to another, whether in terms of their size, their chemical composition or their format. This lack of standardization of the technologies used complicates the reuse of batteries and therefore requires very large volumes of EV production to have enough material at the end of life for reuse. A problem all the more complex since there could be more than 15 different manufacturers of electric car batteries by 2025(13).
- Lower manufacturing cost : if lithium-ion batteries are still relatively expensive to manufacture, their cost continues to decrease. Between 2010 and 2019, the average price per kWh would have dropped from $ 1,200 to $ 156, a decrease of almost 90%. By 2024, the price could even drop to $ 100 per kWh(14). This would represent “only” $ 10,000 (around € 9,200) for a battery with a capacity of 100 kWh, the equivalent of what the Tesla Model S offers, the model at the top of the ranking of the most autonomous electric vehicles. . The problem is that reuse is only viable if the cost difference between new and used batteries remains large, including for stationary storage. However, this gap, which is estimated to be able to reach 70% in the medium term, could fall to only 25% by 2040 if the production cost of new batteries continues to decrease.(13).
- Lack of regulation : if recycling or repair of used batteries is already supervised, this is less the case for reuse. The absence of standards relating to battery performance in second life therefore gives no guarantee to consumers as to the quality of the system developed (charging station, specific storage, etc.). The question of responsibility is also central, since the manufacturer and the manufacturer could blame each other in the event of a problem.
Levers to develop the reuse of batteries
Faced with these different challenges, it is easier to understand the lack of involvement of car manufacturers. However, they are far from insurmountable, provided that we adopt a proactive policy in this area and targeted actions.
- Thinking about a second life from production : the first necessity for manufacturers is to produce electric vehicles with a second life application in mind. The advantage? Manufacture batteries perfectly suited to vehicles, but also to stationary storage, thus reducing the cost of reuse. This is what Renault and Nissan have done. The second had also formalized in 2018 a partnership with Sumitomo Corporation to reuse the batteries of future Nissan Leaf for public and private stationary storage.
- Develop refurbishment : this technique, relatively little used at the moment, consists in replacing the used cells of the battery in order to increase the capacity of the latter. The idea would therefore be to develop and industrialize this "repair" process on a large scale, in order to maintain the difference in value between new and used batteries.
- Create a referent organization : Many global agencies and other manufacturers' alliances are already interested in creating safety standards for reused batteries. However, there is still a lack of a reference body capable of certifying the performance of second-life batteries and ensuring that their use is adapted to the needs of different storage applications.
- Be an actor of tomorrow's practices : in the absence of regulations indicating whether recycling or reuse is the way to go, manufacturers have the possibility of making their own choices and of identifying solutions enabling them to imagine new commercial outlets. This is what Renault is doing by being involved in both recycling and second-life battery programs. The advantage? The French company is experimenting, both with individuals and with public institutions, and determines – on the strength of its feedback – what will be the best path to follow.
(1) Electric vehicles: 700,000 tonnes of batteries to be recycled in 2035 – Le Parisien – 2019
(2) Study: the electric car 4 times less polluting than petrol and diesel – Clean Automobile – 2020
(3) From the well to the wheel – Volkswagen – 2019
(4) European Directive 2006/66 / EC of the European Parliament and of the Council of September 6, 2006 – Official Journal of the European Union – 2006
(5) A Quick Guide to Battery Reuse and Recycling – Union for concerned scientists – 2020
(6) Battery recycling: increasingly “green” – Clean Automotive – 2019
(7) Highly efficient recycling for an excellent ecological balance – Duesenfeld – 2020
(8) Partners – SNAM – 2020
(9) Volkswagen presents the battery recycling program for its electric cars – Caradisiac – 2019
(10) Eramet, Suez and BASF want to reuse the batteries of electric cars – Les Echos – 2019
(11) Electrification of the global car fleet and criticality of lithium by 2050 – Ademe – 2018
(12) Old Electric Car Batteries May Help Cut Costs of Storing Power – Bloomberg – 2020
(13) Second-life EV batteries: The newest value pool in energy storage – McKinsey & Company – 2019
(14) Battery Pack Prices Fall As Market Ramps Up With Market Average At $ 156 / kWh In 2019 – BloombergNEF – 2019