Supplemetary information and dataset to the publication "Evaluation of the tensile adhesion strength of cathode coatings from spent lithium-ion batteries using a centrifugal method"

Lithium-ion batteries are essential for the transition to renewable energy and electrified transport. As their use continues to grow, efficient and sustainable recycling processes are needed to recover valuable materials from spent battery cells. Such industrial recycling processes often rely on hydrometallurgical extraction of valuable metals and require selective removal of cathode coatings from metallic current collector foils beforehand. The efficiency of this decoating strongly affects the yield and purity of the recovered material fractions. In parallel, direct recycling concepts that aim to preserve the structure and functionality of cathode active materials for re-use depend even more critically on controlled decoating with minimal damage to the coating materials. In both cases, the adhesion between these coatings and their substrate foils is a key parameter that governs how easily active material layers can be detached and how efficient the resulting streams of active material and current collector foil can be separated. In this context, a centrifugal testing method was developed to quantify the tensile adhesion strength of cathode coatings and to assess fracture under defined processing conditions. The method enables a systematic evaluation of how different pre-treatment strategies, such as thermal drying, affect coating adhesion. Here it is applied to cathode foils from end-of-life NMC-111 cells thermally pre-treated in air at room temperature, 80 °C, 140 °C, 310 °C and 350 °C. Depending on the pre-treatment temperature, the fracture behavior shifts markedly between adhesive and cohesive modes.