Press release of April 30, 2024

Two times top-level research

Helmholtz Association recognizes HZDR scientists with doctoral awards

The Helmholtz Association awarded Dr. Lukas Körber and Dr. Anna Vanderbruggen its doctoral prizes in the fields of matter and energy in Berlin on Monday, April 29. They received the prizes for their outstanding doctoral theses, which they completed at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the Helmholtz Institute Freiberg for Resource Technology at HZDR. In her research approach, Vanderbruggen uses a proven method to return the graphite from used batteries, which has hardly been recycled to date, to the material cycle. Körber's work contributes to a deeper understanding of magnetic spin waves, which are significant for various future technologies. The prize is endowed with 5,000 euros. Additionally, the Helmholtz Association supports stays abroad of up to six months with a monthly grant of 2,000 euros.

"This is a special moment for the HZDR, as for the first time in one year, two talents from our center have been selected for the awards, which Helmholtz bestows only on the best and most original doctoral achievements," says Prof. Sebastian M. Schmidt, Scientific Director of the HZDR. "Both theses exemplify the pursuit of excellence and innovation that drives our research center. At the same time, they demonstrate the excellent research and training conditions that young scientists find here. I would like to congratulate both Ms. Vanderbruggen and Mr. Körber on this well-deserved recognition. I am sure that they will both have long and successful careers in science."

Bringing graphite back into the cycle

Anna Vanderbruggen has developed a method for recovering valuable graphite from used lithium-ion batteries (LIBs). Her method makes it possible for the first time to separate the fine powder from comminuted LIBs into two valuable products instead of one. This process enables efficient and highly selective recycling of both graphite and metals from used LIBs. Recent tests confirm the purity of the recycled graphite and thus a performance comparable to new graphite.

"My approach utilizes the proven method of froth flotation in the raw material industry to recycle graphite. Froth flotation is an established and efficient process for separating valuable minerals from waste rock for particle sizes of about 10 to 200 micrometers. Graphite typically accounts for 15 to 25 percent of the battery´s weight. By recovering graphite in addition to the 50 percent of metals already being recovered, the EU requirement of 70 percent material recycling by 2030 can be met," Vanderbruggen explains her approach. The goal is a circular battery supply chain that helps to decrease the environmental footprint of battery production and the reliance on raw materials imports from outside the EU.

"A few years ago, it was difficult to make myself heard when I talked about recycling graphite in lithium-ion batteries. At that time, the interest was only on cobalt and nickel. No one recognized the value of graphite back then," says Anna Vanderbruggen. This has changed in the meantime. She has already received several awards for her innovative approach, which is also highly relevant to society. In addition to her successful participation in the Falling Walls competition, which highlights pioneering ideas, she was also honored with the EIT CHANGE Award in 2022. The European Institute of Innovation and Technology (EIT) awards the prize for entrepreneurial and societal excellence.

Exploring the geometry of magnetic vortices

In his doctoral thesis, Lukas Körber dealt with the geometric effects of spin waves. Also known as magnons, they describe the fundamental energetic excitations of ferromagnets. "Such magnets consist of many smaller magnets, known as spins, which are aligned in a certain way," says Lukas Körber, explaining the phenomenon. "You can imagine them as blades of grass that move like waves in the wind. Such waves in magnets have special properties that are useful for information processing, for example, and sometimes change dramatically when the magnet is curved. This makes research into spin waves interesting for future applications that make use of the laws of quantum mechanics."

With his thesis, he not only discovered more about these curvature effects but also developed a method for their calculation using numerical simulation. While such calculations used to take several days, the new software reduces the time to just a few minutes. "We decided to make the method openly available to the scientific community, which is now eagerly using it," says Körber. "For me, this is the highest form of appreciation and I am delighted every time other researchers ask me about it at scientific conferences."

Lukas Körber also discusses the various applications that arise from utilizing spin effects. These include quantum sensor technology, quantum computing and neuromorphic computing. In the latter field, Körber is conducting research within the EU project NIMFEIA (Nonlinear Magnons for Reservoir Computing in Reciprocal Space), in which institutions from four European countries are involved. The project aims to develop new types of hardware with an architecture modeled on the processes of the human brain. This would make it possible to recognize patterns in large data streams extremely quickly and efficiently. Through the project coordinated at HZDR, Körber continues to collaborate closely with his former colleagues from Dresden.

About Anna Vanderbruggen

Born in France, Anna Vanderbruggen studied process engineering at the École National Supérieure de Géologie in Nancy. She then completed her Master's degree as part of the Emerald Erasmus Mundus Master's program. Already during her Master's, she focused on research on recycling graphite from used lithium-ion batteries. This was also the subject of her doctoral thesis, which she completed in 2022 at the Helmholtz Institute Freiberg for Resource Technology and Finland's Aalto University. Graphite recycling is still her core research focus, which she is now continuing at the University of Lorraine in France.

About Lukas Körber

Lukas Körber grew up in Zwickau, Saxony. He studied physics at the Technical University of Dresden. In his master's studies, he specialized in the electronic properties of solids and wrote his thesis on the theory and simulation of nonlinear spin wave dynamics in magnetic vortices. The TU Dresden awarded him a doctorate in 2023 for his thesis "Spin waves in curved magnetic shells" supervised at the HZDR. At the beginning of this year, Lukas Körber continued his scientific career at the Radboud University in Nijmegen, Netherlands, joining a research group that investigates quantum theories of ultrafast dynamics in magnetism.

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Further information:

Dr. Anna Vanderbruggen | PostDoc Battery Recycling
Université de Lorraine
Email: anna.vanderbruggen@univ-lorraine.fr

Dr. Lukas Körber | PostDoc Quantum Theories
Radboud Universiteit Nijmegen
Email: lukas.koerber@ru.nl

Media contact:

Simon Schmitt | Head
Communication and Media Relations at HZDR
Phone: +49 351 260 3400 | Email: s.schmitt@hzdr.de

Anne-Kristin Jentzsch | Press Officer
Helmholtz Institute Freiberg for Resource Technology
Phone: +49 351 260 4429 | Email: a.jentzsch@hzdr.de