Securing a reliable supply of critical raw materials is a key challenge in the global transition to sustainable energy systems. Lithium, in particular, is essential for modern energy storage technologies such as rechargeable batteries used in electric vehicles and stationary storage systems. At the same time, the dependence on a limited number of producing countries is increasing, which underscores the need for alternative and sustainable extraction strategies. In this context, both economic scalability and environmental safety are key alongside technical feasibility.

Seawater contains large overall quantities of lithium and other critical elements, but only at very low concentrations. Additionally, it is dominated by other dissolved ions, such as sodium and magnesium, which makes the selective extraction of lithium particularly challenging. Efficient and selective separation technologies are therefore required to make lithium recovery from seawater economically viable.

This project investigates an innovative approach for the enrichment of lithium from seawater using functionalized magnetic nanoparticles (MNPs). These particles enable a filter-free and environmentally friendly process, as they can be easily recovered from the liquid using magnetic fields. The concept is based on a magnetic nanoparticle-based levitation reactor, in which both adsorption and desorption processes are realized under dynamic flow conditions.

To achieve selective binding of lithium ions, the MNPs are functionalized with specific ligands. Particular emphasis is placed on crown ethers and metal–organic frameworks (MOFs). This project places particular emphasis on scaling MNP production to an industrial level, with the objective of developing a cost-effective, scalable, and high-performance synthesis route. At the same time, environmental impacts are explicitly addressed through the evaluation of potential ecological risks associated with the release of modified nanoparticles, ensuring a holistic and sustainable approach.

References
[1] Nistler, A et al., Anal. Bioanal. Chem.  2019, DOI: 10.1007/s00216-019-01808-z.

Funding                                                                                                                Cooperation                                                                                  
Bundesministerium für Wirtschaft und Klimaschutz (BMWK)                    Hydroisotope GmbH 
                                                                                                                               Solexperts Group
                                                                                                                               Fraunhofer-Institut für Solare Energiesysteme ISE     
                                                                                                                               Geomar Helmholtz-Zentrum für Ozeanforschung Kiel