An Electrophoresis Approach for Recycling Black Mass from Spent Lithium-Ion Batteries

The rapid proliferation of lithium-ion batteries (LIBs) has generated significant environmental challenges due to the disposal of spent batteries. Therefore, identifying an efficient recycling method is critical for resource recovery and waste reduction. In our laboratory, we have adopted the electrophoresis technique to enable phase separation in black mass from spent LIBs. Electrophoresis involves imposition an electrical field so the suspended particles can be driven toward the electrode with opposite polarity. Lithium cobalt nickel manganese oxides (NMC) and graphite exhibit different zeta potentials and densities in black mass. Under a suitable supporting solvent, NMC and graphite could be physically separated and collected. Our approach offers distinct advantages over the conventional chemical leaching routes in terms of reduced energy consumption and chemical waste. To enhance the separation efficiency, we use citric acid as a surfactant that firmly adheres to the surface of NMC particles for a more significant negative zeta potential. Our preliminary results demonstrate that leveraging the lateral electrophoresis and vertical gravitational force could phase-separate the NMC and graphite. Our ongoing research is to optimize the phase separation cell design and conduct scaling-up work to validate the translation of this technique to practical industrial use.