Abstract
The increasing use of lithium-ion batteries (LIBs) has increased the need for physical pre-treatment methods capable of recovering electrode materials prior to downstream recycling processes. Mechanical separation can provide an effective initial removal of electrode coatings; however, residual active material may remain attached to the metallic current collectors, limiting the recovery of clean electrode fractions. In this work, a sequential mechanical–ultrasonic approach is investigated for the recovery of electrode materials from spent commercial 18650 lithium-ion battery cells. The proposed approach combines an initial mechanical removal step with short ultrasonic treatment cycles applied to the residual electrode coating. Mechanical activation between ultrasonic cycles was used to promote the detachment of remaining material while limiting prolonged exposure of the metallic current collectors to ultrasonic treatment. Preliminary continuous ultrasonic experiments showed that extended treatment increased degradation of the current collectors without producing a proportional improvement in coating removal, providing the basis for the sequential procedure. The recovered fractions were characterized to evaluate their composition, structural characteristics, and degree of separation from the metallic current collectors. A mass balance accounted for 14.58 g of recovered cathode material, while a 0.28 g difference remained unaccounted for and could not be experimentally assigned to a specific loss mechanism. X-ray diffraction confirmed chemically distinguishable cathode fractions, while energy-dispersive spectroscopy of the ultrasonic-recovered fraction showed a low average aluminum content of 0.21 wt.%. The results demonstrate that short, mechanically assisted ultrasonic treatments can effectively remove residual electrode material while limiting collector deterioration. These findings support the use of ultrasound as an assisting step following mechanical separation, rather than as a standalone delamination process, for the physical recovery of electrode materials from spent lithium-ion batteries.