Advanced separation technologies for lithium-ion battery recycling: A critical review

The rapid global expansion of the electric vehicle industry has propelled lithium-ion battery (LIB) manufacturing, and recycling end-of-life LIBs is a key strategy to supply the great needs of critical metals and manage the large volume of retired batteries. Separation technology plays a key role in LIB recycling, where it differentiates value-added mineral components for future manufacturing. In this review, we introduce the functions of separation technologies in LIB recycling, present state-of-the-art industrial-scale LIB separation challenges, and analyze the energy consumption and environmental impacts of conventional separations. We then critically examine the working principles and current status of four categories of emerging separation technologies for sustainable LIB recycling: solvent-driven separations, adsorption- and ion exchange-based separations, membrane technologies, and electrochemical technologies. We further identify persistent bottlenecks across these platforms, including selectivity under realistic leachate conditions, chemical durability, reagent sustainability, and product-grade quality. Prospects for process integration and technology convergence are discussed, and a forward-looking roadmap is proposed to bridge the gap between laboratory performance and scalable, closed-loop LIB recycling.