The energy transition and the electrification of mobility are driving rapidly increasing production capacities for lithium-ion batteries. While production scrap is particularly well suited for recycling due to its high material purity, a holistic, economic, and ecological recovery is still lacking. Direct mechanical recycling represents a promising approach to directly return critical raw materials to electrode production and close material loops within manufacturing.

This presentation presents a process for the direct mechanical recycling of anode and cathode residues from water-based Li-ion battery production. A major share of residues originates from quality control during coating and drying, as well as from start-up, shutdown, and stamping operations. The developed process enables the treatment of all coating-related residues to generate material suitable for recoating collector foils, with anode and cathode materials recycled separately. It follows a simple, linear, two-stage strategy designed to facilitate in-house recycling. Self-produced electrode strips, closely resembling industrial residues, were used as reference material.
In the first step, coatings are removed from the collector foils using an aqueous ultra-sonic bath. The resulting water-diluted suspension of active materials and binders is subsequently concentrated by mechanical liquid separation. A recyclate with high solids contents enable flexible blending with fresh battery pastes, minimizing changes to existing production processes while maintaining battery performance. Since Li-ion battery recyclates (black mass) are typically difficult to filter due to small particle sizes and binders, dynamic shear gap cross-flow filtration was applied to achieve the desired solids concentrations [...]