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Training Network for the Design and Recycling of Rare-Earth Permanent Magnet Motors and Generators in Hybrid and Full Electric Vehicles

Periodic Reporting for period 2 - DEMETER (Training Network for the Design and Recycling of Rare-Earth Permanent Magnet Motors and Generators in Hybrid and Full Electric Vehicles)

Reporting period: 2017-09-01 to 2019-08-31

a. What is the problem/issue being addressed?

As increasing numbers of vehicles on our roads become powered by electricity, the problem of how to effectively recycle the rare-earth magnets contained in the motors and generators of these hybrid and full-electric vehicles (EVs) intensifies. In response to this the DEMETER project – the European Training Network for the Design and Recycling of Rare-Earth Permanent Magnet Motors and Generators in Hybrid and Full Electric Vehicles – has looked to solve many of the scientific and technical problems that are currently preventing the effective recycling of these critical materials.
Firstly, the magnets must be identified and removed from existing devices. Then they need to be reprocessed, with the properties of the new magnets being good enough for them to be incorporated into new motors, which of course must be designed in such a way that at their end-of-life (EoL) they can be more easily recycled.

b. Why is it important for society?
Rare earths are vital because they have unique properties, which means that in many cases they cannot be substituted with another element without greatly reducing performance. And this is not just for permanent magnets – although this is probably the largest single use at the moment – but for the many other industries that rely on them. We find rare earths in camera and telescope lenses, catalytic converters, aircraft engines, visors to protect welders and glassmakers, X-ray and MRI scanning systems, televisions and computer screens and other devices that have visual displays. If the supply of rare earths was restricted or even halted, then European society would be very severely affected, probably within weeks. Many industries would be severely hit, jobs would be lost, and manufacturers of products reliant on rare earths would have to stop production. Being able to guarantee the supply of rare earths through a large-scale programme of recycling is Europe’s only option.

c. What are the overall objectives?
The DEMETER project focused on the extraction and recycling of the relatively large rare-earth permanent magnets in electrical drives. In addition to this, DEMETER developed recycling for Nd-Fe-B and Sm-Co magnets, and designed electric motors for the next generation of electric vehicles. Finally, the project developed a complete, “urban-mine to machine”, lifecycle assessment and lifecycle costing methodology for rare-earth permanent magnets to ensure the most environmentally friendly and economical routes are applied for recycling.

d. The conclusions of the action
The 15 ESRs in the project, individually took on huge challenges. They moved to a new country, began work on a new research project, and the majority of them flourished and are now establishing themselves as self-assured, independently minded researchers who are looking forward to interesting careers. They have received top-class training which means they are ready to tackle future challenges with confidence and make a contribution to society.
Their individual research projects have generated some remarkable results. There have been a number of publications in high-impact journals and some very important conference presentations. The ideas relating to the recycling of rare-earth magnets have been advanced on many fronts, and we can conclude that DEMETER has done much to further European aims for a healthier, greener and more sustainable economy.
The research of four of the early-stage researchers (ESRs) was all related to the direct and indirect recycling of Nd-Fe-B and Sm-Co magnets (WP1 in Fig. 2). The magnets for the recycling were obtained from various drive motors and then subjected to recycling treatments. One involved hydrogen at different pressures, which caused the materials to absorb the hydrogen like a sponge and then crumble as a result of the internal pressure of the absorption. Another involved ammonium-based ionic liquids with various anions, which were tested to extract the rare earths. The major advantage of using ionic liquids, as opposed to existing extraction technologies, is that no harmful, volatile and flammable diluents or molecular solvents need to be used.The next four ESRs in WP 2 developed new processing techniques for the production of high-performance Nd-Fe-B and Sm-Co magnets. The research involved the successful deposition Nd–Fe-based films from an ionic liquid, using a new technique called spark-plasma sintering (SPS) to compact and then solidify Sm-Co powders, analysing the microstructures of permanent magnets down to the nanoscale to enable us to identify optimal SPS parameters, and using a process of grain-boundary engineering to enhance the magnetic properties of the magnets.
The third group of ESRs in WP3 designed electric motors for EVs, with the specific aim being to enable the easy future reuse of the magnets in these devices. Altogether, their four different prototypes were investigated in DEMETER. In particular, the work on the claw-pole motor demonstrated the importance of factors like the claw-undercut angle, the claw inside radius, the claw core radius and the claw side-plate thickness when it comes to the design of these very sophisticated devices.

As regards the lifecycle-assessment (LCA) and lifecycle-costing methodologies, which was the subject of WP4, process streams were analysed for their metal content and then further processed using eddy-current separation, high-intensity wet-and-dry magnetic separation and electrostatic separation to physically concentrate the rare earths, some platinum group metals and other critical and strategic elements. The LCA studies highlighted many of the economic and environmental factors associated with the different types of recycling.
The DEMETER project has made great progress in a number of key areas. A new state of the art is being registered in terms of innovative ways of accessing these valuable materials in waste streams, new methods to extract the rare earths from these materials in environmentally friendly ways are now much better understood and have moved closer to market realisation, while completely new arrangements of permanent magnets in recycling-friendly electric motors have been designed. Individually the ESRs have made important impacts, with six of them already receiving their PhD degrees, and another seven set to do so within the next few months.

In terms of socio-economic impact and the wider societal implications of the project, DEMETER promotional video ( was launched and has had more than 15K views to date (15/10/2019). It was presented as an example of successful communication and outreach at the EC Info Day (December 2016), and posted on the Marie Curie Actions website. On the 26th of September 2017, the DEMETER video won a prize at the EC JRC conference as it demonstrated on how complex scientific processes can be presented in a clear manner to a broad audience. DEMETER Promo video 2, launched in January 2019 was as successful, also with more than 15K views to date:

Finally, perhaps the most important DEMETER impact over the long term will be the founding of REIA: the global rare earth industry association in 2019 ( A first of its kind. REIA will help members of the rare-earth community REE to interact with the global rare-earth industry.
How the research was organised in 7 work packages in the DEMETER project
Claw-pole motor with recycled magnets
Supply risk of RE and their importance to clean energy
REA: launch of the global rare earth industry association