LOWVOLMON – Monitoring of low-volatile electrolytes in the mechanical recycling process chain

The project deals with the electrolyte in a lithium-ion battery, a mixture of special organic solvents accounting for up to20 % of the total mass of a battery cell. In mechanical recycling processes, the electrolyte is released during shredding or dismantling of the cell by evaporation. For electrolyte recovery, state-of-the-art vacuum drying systems are used reducing the electrolyte content to such an extent that emission protection is guaranteed in the subsequent processing steps. However, not all components of the electrolyte mixture are completely removed since low-volatile components with a high boiling temperature remain on and in various battery components and materials. To date, this amount has not been quantified, but initial estimates suggest that it is about 10-20 % of the total mass of the electrolyte filling of a battery cell. This residual content of low-volatile organic substances is not inert, it just evaporates more slowly, so that such electrolyte vapour can accumulate in consecutive process steps. Furthermore, the electrolyte acts as an unwanted process chemical in flotation and hydrometallurgical processes complicating an efficient processing there.