Due to their chemical resistance and water-repellent properties, PFAS are commonly used as a coating for textiles, such as Gore-Tex, and for non-stick cookware, like Teflon. A major concern is that abrasion from using these products, along with emissions from their production and improper disposal, can lead to the release of PFAS into the environment. This contamination allows PFAS to enter both the animal and plant ecosystems, ultimately increasing their presence within the human body.

Many PFAS (per- and polyfluoroalkyl substances) are toxic and suspected of causing cancer or other diseases. For this reason, discussions around banning these chemicals, or specific types of them, are ongoing. Known as “eternal chemicals,” PFAS accumulate in ecosystems and the human body, posing long-term health risks. To mitigate these risks, stricter regulations are being introduced to limit their use and reduce exposure.

In Europe, PFAS are governed by various regulatory frameworks, including the REACH and CLP regulations. The REACH regulation specifically addresses substances of very high concern, such as certain PFAS, due to their persistence, bioaccumulation, and toxicity. For example, substances like C9-C14 PFCAs have been banned under REACH since February 2023, while other PFAS, including PFHxA and PFHpA, are currently under review for potential restrictions.

These regulatory actions reflect a global trend aimed at increased monitoring of PFAS use and a reduction of their application in critical areas. Consequently, the search for alternatives and the development of new, more sustainable materials have become essential aspects of research and industry progress, particularly in sectors like battery manufacturing.

Two types of PFAS chemicals commonly found in battery cells are Polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), commonly referred to as "Teflon." These substances are used in small quantities as binders to hold the active material particles together and attach them to the electrode foil. Their chemical stability is crucial for ensuring reliable cell performance, as they do not react with the active materials or other components of the cell.

PVDF is particularly prevalent in lithium-ion batteries (LIBs) that use NMC (lithium nickel manganese cobalt oxide) and LFP (lithium iron phosphate) chemistries. Its high electrochemical stability helps protect the battery from oxidation reactions, thereby extending its service life. However, recycling these PFAS-based binders presents a significant challenge. Currently, only thermal recycling through pyrolysis has been developed, which involves filtering out toxic degradation products.

PFAS, particularly polyvinylidene fluoride (PVDF), are crucial for making electrodes in lithium nickel manganese cobalt oxide (NMC) cells due to their sensitivity to moisture. As water cannot be used as a processing solvent, an organic solvent like N-methyl-2-pyrrolidone (NMP) is required to work with PFAS-based binders.

In contrast, lithium iron phosphate (LFP) cells could use water-based processing, allowing for PFAS-free binders. However, this method is still limited to laboratory or pilot-scale projects and hasn't reached industrial production.

A promising avenue for the future is the development of a solvent-free dry coating process, which could offer ecological benefits and significant energy savings. Increased research in this area may enable PFAS-free battery production in the long run.

The issue of PFAS (per- and polyfluoroalkyl substances) makes it essential to critically evaluate dry coating technology. Although dry coating is marketed as a sustainable alternative to traditional electrode production, it significantly reduces energy consumption by eliminating the need for solvent evaporation and drying. This reduction in energy use leads to direct resource savings and lower CO₂ emissions during production.

However, the technology is currently dependent on using PTFE (polytetrafluoroethylene) as a binder, which is a controversial PFAS chemical known for its persistence in the environment and associated ecological issues. Consequently, dry coating presents a complex dilemma: it offers potential energy savings but raises significant ecological concerns related to the use of PFAS, particularly regarding the production, usage, and disposal of these materials.

From an environmental standpoint, dry coating is an ambivalent solution. While it provides a means to reduce energy consumption, it increases reliance on PFAS compounds. A thorough sustainability assessment of this technology should focus on developing and integrating alternatives to PFAS binders.

Currently, PFAS-free binders are unlikely to dominate the lithium-ion battery market, as alternatives compatible with all cell chemistries are still under development. Research is focused on creating PFAS-free binders that match the performance of PFAS-based ones while reducing ecological impact. There is also an exploration of alternative cell chemistries that rely less on PFAS without compromising battery performance.

Additionally, improving recycling methods for PFAS-containing lithium-ion batteries is crucial to minimize their environmental impact. Currently, effective and environmentally friendly methods for PFAS degradation are not available.

Overall, developing PFAS-free batteries requires innovative materials, processes, and recycling technologies that are closely linked to meet technological and environmental needs.