How Are Forever Chemicals (PFAS) Used in Batteries?

Written by

Alicja Gos

October 17, 2024

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Per- and polyfluoroalkyl substances (PFAS), colloquially known as “forever chemicals,” are a class of about 16,000 human-made compounds that are used extensively in everyday consumer goods such as non-stick cookware, cleaning agents, personal care products, and food packaging. Moreover, PFAS are also widely employed in essential applications, including microelectronic devices, medical equipment, fire extinguishing agents, and energy storage solutions. Unfortunately, they do not break down naturally and can accumulate in body tissues and cause wide-ranging health issues¹.

While public attention typically rests on the risks introduced by the presence of PFAS in personal consumer products that can, or are at least perceived to more directly harm individuals, many PFAS-containing commercial and industrial products also pose uncertain levels of risk with an increasing cause for concern. For batteries, which can use PFAS in many different components, new research, and increasing regulatory scrutiny threaten to complicate the already difficult task of developing safer, more efficient, and highly sustainable technologies by requiring the substitution of PFAS with less hazardous alternatives. This begs several key questions: how are PFAS used in batteries, what should industry players know about their risks and regulations, and what can be done to accelerate their replacement?

Applications of PFAS in Batteries

While PFAS are infamously used in non-stick cookware in the form of Teflon (polytetrafluoroethylene), it is less well known that they are also used in batteries for several critical components. One such example is their application in electrolytes as additives, increasing performance, such as F-EPE and lithium salts with PFAS anions, providing a good lithium-ion transport for lithium-ion batteries. In addition, for lithium metal batteries (i.e., those containing lithium metal anodes), PFAS solvents offer high performance and extended lifespans due to their increased stability under operating conditions.

Another common example is their use in electrode binders, which are responsible for holding the active material particles together. Polytetrafluoroethylene (PTFE) is one example of a common PFAS-based electrode binder material, unique for its superplastic phase, allowing fibrils to form down to the size of tens of nanometers². Additionally, several other important PTFE properties are leveraged for cell performance, including chemical and electrochemical stability and high toughness with moderate flexibility. Moreover, PTFE also exhibits good dispersion and thermal stability, which also help in the production process³.

Other use cases include separator coatings, gaskets, seals, pipes, valves, sealants, and more. In fact, this last category of mechanical parts inside the cells is the only one with non-PFAS alternatives available on the market. These components are important for cell safety, keeping the other materials enclosed and the cathode and anode separated, while also ensuring chemical stability even in harsh chemical environments³. Thus, we have the answer to our first question: PFAS are used in numerous battery components, and contemporary battery technology remains dependent on their use and availability.

Emerging Research and Evolving Regulations

The widespread use and growing public health concerns associated with PFAS have led regulatory agencies in Europe², the USA⁴, and Canada⁵ to place restrictions and reporting obligations on PFAS manufacturing and import companies, including the banning of many individual substances. In fact, because of the now widely recognized human and environmental toxicity of many PFAS, regulators are exploring restrictions and outright bans on either all PFAS entirely or large sub-categories, regardless of the availability of specific chemical hazard data⁶. This approach of “horizon restrictions” is facing pushback from industry organizations (e.g., RECHARGE: an advocate for use of lithium ion batteries); however, it is a near certainty that some form of regulatory actions impacting some or all of the aforementioned battery components will be enacted.

At the same time, a recent publication by a Duke University team led by Dr. Lee Ferguson calls lithium-ion batteries an increasing source of bis-FASIs (bis-perfluoroalkyl sulfonimides), an understudied type of PFAS with a yet unknown contribution to total PFAS-related health and environmental impacts. Their publication reveals that these PFAS compounds are problematic both in communities near manufacturing sites and anywhere that batteries are disposed of⁷. The report states, “The bis-FASI concentrations in these samples were commonly at parts per billion levels,”⁸ which, compared to EPA maximum set levels for similar chemicals, is alarming, as this is several orders of magnitude more than for PFOA and PFOS. Even though the study focused on the most popular lithium-ion batteries, it is important to mention that their most relevant alternatives also use PFAS, e.g., nickel-based, zinc-air, lithium-based, solid-state, or sodium-ion batteries3. With this, we have the answer to our second question: PFAS are used to produce many different types of batteries and pose human and environmental health and safety risks, which regulators are addressing with new and more comprehensive rules and restrictions.

Addressing the Concerns of PFAS Battery Components

New research and regulatory actions reflect the growing demand to minimize the amount of PFAS materials that are used and need to be manufactured. The first approach that can be used to address these concerns is improved treatment and recycling. Theoretically, fluoropolymers could be completely decomposed during the pyrometallurgical recycling process², and it has been assessed that up to 96% of bis-FMeSI is recoverable⁹. Unfortunately, studies estimate that only 5% of lithium-ion batteries are currently being recycled, which could be extrapolated to other types of batteries as well¹⁰.

Today PFAS are estimated to be 1-8% of the total lithium batteries tonnage, and it is predicted that 2 million metric tons per year of lithium batteries will be disposed of by 2030¹¹, resulting in the annual generation of 20,000 to 160,000 metric tons of waste PFAS from lithium batteries alone. While treatment and recycling are likely to remain a supporting approach, due to the higher than desired associated costs and therefore high practical barriers, it is more desirable that the problems posed by use of PFAS be addressed via integrating safer alternative components. Most of the non-PFAS battery technologies are on a low technology readiness level, currently unable to meet the demands of mass-produced commercial lithium-ion batteries. Some alternatives for PFAS for other technologies like solid-state batteries (e.g., thermoplastic polymers) exist but are complex and add additional time and cost to the manufacturing process².

Recently, one battery component manufacturing firm released electrodes that are manufactured without the use of any forever chemicals¹². They offer high-voltage lithium cobalt oxide (HV-LCO), lithium iron phosphate (LFP), and nickel manganese cobalt (NMC) electrodes while also advertising competitive pricing compared to other cobalt-based electrodes. These are exciting developments for the battery world on the component level, but more steps must be taken to make the entire battery PFAS-free. Moreover, PFAS-free electrolyte solvents, additives, salts, and electrode binders remain elusive, and further testing and experimentation are needed to realize new materials that improve performance using safer substances. This is where NobleAI and our Risk Assessment and Ingredient Replacement (RA/IR) capabilities can answer our third question.

Accelerating PFAS Replacement with NobleAI’s RA/IR Solution

To help evaluate regulatory risks and identify safer alternatives, we’ve developed the NobleAI Risk Assessment service and Ingredient Replacement (RA+IR) capability solution, part of the NobleAI Visualizations, Insights & Predictions (VIP) Platform. RA+IR evaluates a product formulation to provide a risk assessment for each component. Using this risk assessment report, at-risk formulations can be easily identified, highlighting ingredients that are currently restricted, under review by a regulatory agency, or structurally resembling a similar compound with known toxicity, environmental risks, or other high-risk hazard data. Flagged components can then be replaced with alternatives using Science-Based AI (SBAI) models which find formulations that achieve the desired performance. With RA+IR and the other powerful features afforded by the VIP platform, replacing hazardous formulation ingredients is made quicker, easier, and more affordable than ever before. If you want to learn more about how the RA+IR tool can benefit your battery technology or other product formulation, request a demo today!