Migration and Transformation Mechanism of Toxic Electrolytes During Mechanical Treatment of Spent Lithium-Ion Batteries

Recycling spent lithium-ion batteries (LIBs) has great environmental and economic benefits. However, the potential environmental impacts of toxic electrolytes are always ignored in this process. In this paper, the migration and transformation of the toxic electrolytes including organic solvents and fluorides are studied, in which spent LIBs were mechanically treated to simulate actual operating conditions. Besides, for the convenience of analysis, LIB components were classified into strip-shaped, powdery, and liquor components according to their unique properties. The results indicated that strip-shaped components (shell, Cu/Al foil, and separator) were converted into large/middle particle size products (PSPs), while powdery components (cathode, binder, and anode) were converted into small PSPs by mechanical force. Therein, the obvious transformation and deformation of liquor electrolytes were observed, and the residual products were mainly distributed in plastics, anode, and cathode. In addition, low-boiling organic solvents escaped into air causing fire hazard and adverse health effects, and decomposed products of lithium hexafluorophosphate (LiPF6) posed risk of corrosions and acute toxicity. The findings can provide instructions for preventing from hazardous pollutants in the practical application.