Johannes Öhl, a research associate at Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS, looks at end-of-life traction batteries and how there is a need to improve the process of the ever-increasing volume of these batteries entering our vehicle recycling yards.
The market for electric vehicles has grown significantly in recent years – and a large number of end-of-life traction batteries is foreseeable in the near future. Several steps are necessary for material recycling, including collection, transport, dismantling and material recovery.
The task in the upscaling project “AutoBatRec2020”, coordinated by Fraunhofer IWKS and funded by EIT Raw Materials in the Horizon2020 framework, is to analyse current recycling strategies and develop new processes with a focus on high-volume input streams.
Current traction battery recycling
The first steps in battery recycling are not directly related to material recovery, but to take back the batteries and feed them to the recycling process. Public battery collection does not concern industrial and automotive batteries contrary to household batteries. The battery distributor, typically the car manufacturer, is obliged to enable a drop-off for end-of-life batteries and is responsible for adequate recycling. Therefore, the recycling company often organises the collection of batteries, e.g. at Cawleys in the UK or Umicore in Belgium and Germany.
Since high capacity batteries may show thermal reaction, ignition and release of toxic substances in rare cases, shipments are classified as dangerous goods. Depending on the battery’s condition, elaborate packaging is required to ensure safe transport, especially for defective batteries.
Current battery recycling processes normally consist of three basic treatment techniques:
- mechanical
- pyrometallurgical
- hydrometallurgical
Mechanical treatment means all dismantling, shredding, and respective sorting steps, a process which is mainly used for initial treatment. In pyrometallurgical processes, high temperatures are used for chemical reactions or melting of contained metals. Hydrometallurgy mostly serves for refinement of recovered materials to high quality.
The available industrial recycling processes always combine these methods in varying shares. The full recycling process yields components like electric connectors, electronics and housing material as well as copper, cobalt and nickel compounds. Examples are the mainly pyrometallurgical process at Umicore and the mainly hydrometallurgical process at Fortum from Finland.
Challenges and future developments
In the next five years, the mass of end-of-life traction batteries will increase fivefold in Europe (2020: 50’000 t, 2025: 250’000 t). To deal with such large quantities of batteries will not be possible with today’s regulations and recycling capacity.
The current solutions regarding collection and transport only work with low quantity of end-of-life batteries, because of high efforts for packaging and weight limitations per transport unit. With expected high volume streams, the cost of transport will not profit from the economics of scale. This bears high logistical and cost-related risks. A harmonisation of automotive battery collection across Europe in respective public organisations is necessary.
Transport regulation must be unrestricted to transport functioning batteries dismantled from cars in the same way as new batteries. Since most batteries are not damaged at disposal, significant cost-saving is possible without increasing safety hazards.
Another consequence of batteries still being in good shape at disposal is the need for reuse of such batteries. Main barriers for widespread reuse are unclear warranty situation, a lack of experience with the service life-time and missing market structures. There is currently only one company in Europe known for recovering cells and modules from various sources to build new modules, SNAM in France. We expect a lot more activity in this sector in the near future due to growing demand from stationary storage, upcoming standardisation and increased experience with long battery life.
The dismantling of automotive batteries can become difficult at large streams because the model and constructive variety still demand a manual workforce. A key point in “AutoBatRec2020” is the evaluation of automation steps to integrate into the dismantling steps to increase throughput.
Considering material recovery, current metallurgical processes are already available on a large scale from conventional applications in metal winning. There are however still possibilities to increase energy efficiency. Our scope is the extraction of valuable material fractions from cells (copper and aluminium foils, housing steel, plastics, electrode active material) with a focus on mechanical techniques with high throughput and high energy efficiency.
Johannes Öhl, johannes.oehl@iwks.fraunhofer.de
Visit: www.iwks.fraunhofer.de
