Fluorinated substances in lithium-ion batteries and solid state batteries: Recycling challenges and environmental impacts

The growth of lithium-ion batteries (LIBs) in consumer electronics and the electric vehicle fleet has highlighted the need to address recycling issues. Fluorinated compounds, including per- and polyfluoroalkyl substances, are used in multiple battery components such as electrolytes, lithium salts, binders, and separators. Little is known about the breakdown and emission of fluorinated compounds during battery recycling processes. Solid-state batteries (SSBs) are considered as the next generation of energy storage technology due to their higher energy density and greater safety. However, the application of fluorinated polymers and fluorinated solid-state electrolytes poses challenges for their recycling. Improper disposal of spent batteries in landfills has the potential to release hazardous materials and harmful emissions through thermal runaway. Recognizing the critical need for battery recycling, we review the fluorinated substances used in LIBs and SSBs, their disposal management methods, and associated environmental impacts from landfilling and recycling techniques. Specifically, we carefully examine the emissions accompanied with pyrometallurgy recycling approaches. This work highlights the need to investigate transport behaviors of fluorinated compounds during battery recycling to eliminate environmental and human health risks and promote sustainable battery management strategies.