First Field Evidence of Diverse Cyclic, Linear, and Fluorinated Carbonates in Dusts from Industrial Lithium-Ion Battery Recycling

Industrial recycling of spent lithium-ion batteries (LIBs) is expanding rapidly, yet its emissions of electrolyte-derived organic contaminants remain largely uncharacterized. Here, we provide the first field evidence that industrial LIB recycling is a significant source of diverse cyclic, linear, and fluorinated carbonates to the indoor environment. Using compound-specific GC-MS/MS, we screened 20 carbonates in 64 dust samples from a representative industrial-scale LIB recycling plant in China. Twelve carbonates were ubiquitously detected, including five cyclic carbonates, six linear carbonates, and one fluorinated carbonate, with total concentrations reaching up to 16,700 ng/g (mean: 3,870 ng/g). The contamination profile was dominated by cyclic carbonates (e.g., propylene carbonate and ethylene carbonate) and volatile linear carbonates, broadly reflecting commercial LIB electrolyte formulations. Notably, the frequent detection of 3,3,3-trifluoropropylene carbonate (TFPC) highlights the emission footprint of advanced fluorinated additives. Strong positive intercompound correlations indicate their corelease from residual electrolytes during LIB pretreatment. These findings significantly expand the chemical footprint of LIB recycling, identifying carbonate electrolytes as another abundant and critical class of new pollutants of emerging concern that necessitate urgent multimedia environmental monitoring and occupational exposure assessments.