Fluorine-Free Binder Strategies for High-Nickel Cathodes: Toward PFAS-Free Lithium-Ion Batteries

With the rapidly growing demand for high-energy-density batteries in electric vehicles (EVs), high-nickel cathodes and their supporting binders have become increasingly important, with stricter performance requirements. However, poly(vinylidene fluoride) (PVDF), the conventional binder for high-nickel cathodes, is showing clear limitations, and the emergence of per- and polyfluoroalkyl substance (PFAS) regulations underscores the urgent need for alternatives. Consequently, fluorine-free binders are receiving significant attention as viable substitutes. Recent studies have highlighted their potential by enhancing electrochemical performance through improved mechanical integrity, reinforced interfacial stability, and better dispersion of electrode components. Nevertheless, comprehensive and systematic evaluations that simultaneously address energy density, electrochemical performance, and processability remain insufficient for the practical replacement of PVDF. This review examines current PVDF-based strategies for improving binders in high-nickel cathodes and provides an updated overview of fluorine-free binder approaches as promising alternatives. In addition, we emphasize the need for systematic, process-specific feasibility studies to advance fluorine-free binders capable of supporting high-nickel cathodes. This contribution aims to guide the rational design of next-generation, PFAS-free binder systems that satisfy both industrial performance demands and emerging regulatory requirements.