Influence of Pretreatment Strategy on the Crushing of Spent Lithium-Ion Batteries

The rising production of lithium-ion batteries (LIBs) due to the introduction of electric mobility as well as stationary energy storage devices demands an efficient and sustainable waste management scheme for legislative, economic and ecologic reasons. One crucial part of the recycling of end-of-life (EOL) LIBs is mechanical processes, which generate material fractions for the production of new batteries or further metallurgical refining. In the context of safe and efficient processing of electric vehicles’ LIBs, crushing is usually applied as a first process step to open at least the battery cell and liberate the cell components. However, the cell opening method used requires a specific pretreatment to overcome the LIB’s hazard potentials. Therefore, the dependence on pretreatment and crushing is investigated in this contribution. For this, the specific energy input for liberation is determined and compared for different recycling strategies with respect to dismantling depth and depollution temperatures. Furthermore, the respective crushing product is analyzed regarding granulometric properties, material composition, and liberation and decoating behaviour depending on the pretreatment and grid size of the crushing equipment. As a result, finer particles and components are generated with dried cells. Pyrolysis of cells as well as high dismantling depths do not allow to draw exact conclusions and predictions. Consequently, trends for a successful separation strategy of the subsequent classifying and sorting processes are revealed, and recommendations for the liberation of LIBs are derived.