Influence of a pyrolysis at different temperatures on the mechanical recycling efficiency of Li-ion batteries

The integration of a pyrolysis stage into the mechanical recycling process of Li-ion batteries is supposed to improve the decoating of the electrodes, the recovery of valuable components and the overall quality of the products. The effectiveness of the pyrolysis process depends on the applied temperature as the various components of a Li-ion battery melt, evaporate and decompose at different temperatures. The decomposition temperature of the cathode binder is a crucial factor in the thermal mechanical recycling process. Temperatures below this threshold have a negative impact on the recovery rates, as the melting of binder and plastics reduces the efficiency of the recovery process. Conversely, higher temperatures facilitate the recovery of the cathode coating metals (Ni, Co, Li) into the black mass. The majority of the metals (92-98%) are recovered and, following hydrometallurgical treatment, can be reused for cell production, thereby closing the loop and reducing the consumption of raw materials and enhancing the sustainability of batteries. Moreover, the decomposition of the organic components, including binders and plastics, improves the quality of the products, thereby reducing the necessity and extent of further treatment.