Identification, Risk Assessment, and Management Strategies for Emerging Pollutants in the Life Cycle of Lithium-Ion Batteries
The global production, inventory, and retirement of lithium-ion batteries are increasing, while new technologies and materials for safety introduce various binders, lithium salts, flame retardants, and solvents, some of which may be emerging pollutants (EPs). This study identifies 43 EPs across 6 categories in the entire life cycle of lithium-ion battery production. Electrolytes contain the most EPs, including per- and polyfluoroalkyl substances (PFASs) lithium salts and solvents, as well as organophosphorus flame retardants. Production emissions of 1,3-butadiene (1,3-BD), dichloromethane (DCM), and N-methylpyrrolidone (NMP), and release of ultra-short-chain PFASs such as bis(trifluoromethylsulfonyl)imide (NTf2) and trifluoromethanesulfonamide (TfNH2) from discarded batteries require attention. Health risk assessments at production and disposal sites show that DCM poses the highest carcinogenic risk at production sites, exceeding the EPA's basic carcinogenic risk value of 1×10−6 but below the critical value of 1×10−4, with non-carcinogenic risk below the EPA threshold of 1. At disposal sites, tris(1,3-dichloro-2-propyl)phosphate (TDCPP) poses the highest carcinogenic risk, below 1×10−6, while tri(2-chloropropyl)phosphate (TCPP) exhibits the highest non-carcinogenic risk, below 1. Comparison of domestic and international regulations highlights gaps in domestic regulations. Recommendations include tiered management of similar-function chemicals, research on alternatives for high-risk chemicals, implementation of clean production mechanisms, establishment of green product standards, and development of guidelines for managing EPs. This study comprehensively summarizes EPs in the lithium-ion battery life cycle, providing technical support for their management.