Developing safe and efficient recycling processes is essential for the sustainability of the lithium ion battery technology, given its rapid scale‐up and dependence on critical raw materials. This study systematically investigated the chemical implications of wet mechanical processing on battery constituents by shredding electric vehicle cells under a concurrent water spray. Therefore, the active material and electrolyte composition of the cells were characterized prior shredding, as well as the resulting process water and black mass sediment using solid phase extraction/gas chromatography‐flame ionization detection, gas chromatography‐mass spectrometry, ion chromatography‐conductivity detection‐high resolution mass spectrometry, and inductively coupled plasma‐optical emission spectroscopy to resolve elemental distribution and electrolyte degradation mechanisms. Wet shredding enabled early‐stage lithium enrichment by solvation of conductive salts, while metals from the cathode and current collectors remained largely insoluble. Subsequent storage of the black mass suspension induced cathode material degradation by leaching ≈16% of the lithium. Electrolyte solvents and additives present in the cells were identified in the process water, but tended to hydrolyze at varying rates depending on the compound, temperature, and pH, which limited solvent integrity. PF 6 ‐ remained stable in the process water for months, across a wide pH range, and at elevated temperatures, with no evidence for further hydrogen fluoride and organo(fluoro)phosphate formation. These findings define operating windows for wet shredding, assess potential operational safety risks, and provide insights for process optimization to maximize recovery efficiencies.
Buchmann et al. (Sun,) studied this question.