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 man-agement 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 pro-duction 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 depend-ence on pretreatment and crushing is investigated in this contribution. For this, the energy input for liberation is determined and compared for different recycling strategies with respect to dis-mantling depth and depollution temperatures. Furthermore, the respective crushing product is analyzed regarding granulometric properties, material composition and liberation and decoat-ing behaviour depending on the pretreatment and grid size of the crushing equipment. Finer particles and components are generated with dried cells. Pyrolysis of cells, as well as high dis-mantling depths, do not allow to draw exact conclusions. The calculated and measured mass-specific mechanical energy input of different dismantling depths shows good accuracy. Consequently, trends for a successful separation strategy of the subsequent classifying and sort-ing processes are revealed, and recommendations for the liberation of LIBs are derived.