Methodology for evaluation of lithium-ion black-mass battery recycling

In response to the growing demand for critical raw materials, the European Commission is actively pursuing strategies to recycle these materials from various sources, including disused batteries. One of the significant challenges in this endeavor is the heterogeneous nature of the materials arriving at recycling plants, necessitating effective process evaluation. In this study, crushed scooter batteries were utilized, and a range of analytical techniques were employed to initially characterize the composition of the raw material and subsequently evaluate previous physical separation processes efficiently, effectively, and economically. The analytical methods utilized included scanning electron microscopy with energy-dispersive X-rays spectroscopy (SEM–EDS), X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), loss of ignition (LOI), and differential scan calorimetry (DSC). In addition, two separation techniques were conducted: froth flotation and sink-and-float tests. The cathode's oxide type was identified through XRD analysis, and statistical methods were applied to all XRF analyses. Furthermore, the other analytical methods facilitated the determination of flux compositions, enabling the assessment of process performance. Regarding the robustness of the presented method, as is well known, performing a complete characterization of a material, including XRD, AAS, XRF, DSC, and SEM, could comprise a relatively high time if it is to identify the efficiency of a process (we estimate in several days, and even weeks). However, by reducing the analytical methods to LOI, XRF, and stream sampling, it is possible to conduct process efficiency evaluation in a few hours. This methodology would give the opportunity to achieve effective verifications in a short time and reduce possible efficiency problems in a treatment plant of this type of material.