Sorting Lithium-Ion Battery Electrode Materials Using Dielectrophoresis

Lithium-ion batteries (LIBs) are common in everyday life and the demand for their raw materials is increasing. Additionally, spent LIBs should be recycled to achieve a circular economy and supply resources for new LIBs or other products. Especially the recycling of the active material of the electrodes is the focus of current research. Existing approaches for recycling (e.g., pyro-, hydrometallurgy, or flotation) still have their drawbacks, such as the loss of materials, generation of waste, or lack of selectivity. In this study, we test the behavior of commercially available LiFePO₄ and two types of graphite microparticles in a dielectrophoretic high-throughput filter. Dielectrophoresis is a volume-dependent electrokinetic force that is commonly used in microfluidics but recently also for applications that focus on enhanced throughput. In our study, graphite particles show significantly higher trapping than LiFePO₄ particles. The results indicate that nearly pure fractions of LiFePO₄ can be obtained with this technique from a mixture with graphite.