The second life of an electric car's battery also has to end at some point. And then? What happens to the valuable metals contained in spent lithium ion batteries, which will grow to form substantial raw material deposits in the decades ahead?
Fifty percent of a battery (measured by weight) must be recycled at the end of the product life cycle. This is what the currently valid EU directive from 2006 stipulates. Technically speaking, this is not a problem. Market leader Umicore, for example, melts down the batteries and says it can recycle between 60 and 70 percent of the original battery. For some materials, such as cobalt and nickel, the recovery rate is even more than 90 percent¹.
Melting, shredding, shocking
The process does not require heating and also allows 96 percent of all battery components to be returned to a new cycle. The batteries are shredded into fine powder under nitrogen. The materials are shredded and mechanically separated from each other: into plastics, different metals and the so-called black mass, the active material from the cell. This method can also be performed decentrally in mobile containers directly at the battery collection points. This saves transport kilometers and helps to reduce CO₂ emissions by around 40 percent when producing new lithium-ion batteries using secondary raw materials compared to the use of new recyclable materials. In the subsequent hydrometallurgical processing, a kind of chemical post-treatment, the individual metals such as cobalt, lithium, manganese and nickel are then dissolved out of the active mass, cleaned and recovered in the form of salts.
At the Fraunhofer Institute for Silicate Research (ISC), researchers in the project group “material cycles and resource strategy” (IWKS) are working on increasing the eco-efficiency of recycling compared with conventional processes. In this approach, controlled shock waves² are used to systematically pulverize batteries and separate their constituent materials. The benefit of this method is that, unlike waste materials, the reclaimed materials can be reused without any further processing. This saves energy, as explained in more detail by the industry publication "Ingenieur"³ and Johannes Öhl, head of the AutoBatRec2020 recycling project at the Fraunhofer ISC, in an interview for this battery special.
Recycling needs mass
It goes without saying that even the most efficient method needs to be cost-effective. This is currently the biggest obstacle in setting up a recycling system on an industrial scale. In a report issued in December 2019, the ADAC (German Automobile Association) drew the following conclusion: "While it is currently possible to reclaim most battery materials, the steps of the process are still too energy-consuming and expensive in some cases⁴."
This is partly due to the low degree of automation in the current recycling processes. Similarly to the establishment of a charging infrastructure, there is a "chicken or the egg" problem in this respect. It is only worthwhile for disposal providers to operate industrial recycling facilities if they are able to process old batteries in sufficient quantities.
However, experts do not expect this volume to be achieved until about twenty years from now. That is when the batteries in the current electric vehicle series will be ultimately recycled on a large scale following the end of their guarantees and their second life in a mass storage facility. A future challenge may be to adapt the current processes developed now to battery types that will be launched on the market in the future on the basis of other technologies.
Fewer Resources, more sustainability
However, it is also clear that the link between growth and the consumption of resources needs to be broken in order to reduce traffic-related CO₂ emissions and pave the way for electromobility. Mercedes-Benz has therefore set itself the goal of reducing the use of primary resources in its drive trains and batteries by 40 percent compared to current electric and hybrid vehicles. The use of waste materials, and nickel, cobalt and copper in particular, plays an important part in this⁵. "We want to use the materials that we are incorporating into today's batteries for new batteries in the future," said Manuel Michel, who is in charge of the Circular Economy Battery project in Daimler's Research department. The engineer will provide details of the progression from design for recycling to the cooperative establishment of closed cycles in the next edition of our battery special.
As a partner in the AutoBatRec2020 research project, Daimler is also working with scientists and practitioners involved in the recycling economy to investigate the prerequisites for an economically and environmentally sustainable recycling concept. This includes a battery design that takes future recycling into consideration – an aspect that also plays an important role in the remanufacturing of high-voltage batteries.
Plea for the quota
Politicians can and should also help accelerate the build-up of comprehensive recycling solutions. The existing EU directive is to be fundamentally revised in 2020 because it is simply not set up for the collection, transportation or recycling of electric vehicle batteries⁶.
In this context, the ADAC (German Automobile Association) is also calling for recycling targets to be increased from 50 percent to over 90 percent, combined with "ambitious requirements" for cobalt, nickel and lithium. Kerstin Meyer from the Agora Energiewende think tank also welcomes this proposal. The expert also proposes a rental model in which manufacturers would have a stronger interest in designing batteries with a view to the future recycling of the materials⁷. This would also benefit the vision of rolling material supplies, which will gradually complement the reduction of primary materials. In the long term, Agora Energiewende calculates that up to 40 percent of the cobalt and lithium required for electromobility could be covered by recycling.
² Waves of pressure are used to separate the individual components of the battery, source: https://www.r4-innovation.de/de/new-bat.html