Lithium-ion batteries are integral to the EV industry, powering the shift towards cleaner transportation. However, recent scientific discoveries have unearthed a significant environmental concern: per- and polyfluoroalkyl substances (PFAS) in these batteries. PFAS, often referred to as “forever chemicals,” are notorious for their persistence in the environment and potential health risks.
A peer-reviewed study published in "Nature Communications" has highlighted the presence of a specific class of PFAS, bis-perfluoroalkyl sulfonimides (bis-FASIs), in lithium-ion batteries. These chemicals enhance battery safety and performance by reducing flammability and improving electrical conductivity. However, their environmental impact is profound. Scientists detected high levels of PFAS in air, water, snow, soil, and sediment samples near PFAS manufacturing plants in the United States, Belgium, and France.
PFAS accumulate rapidly in the environment and do not degrade over time. They have been linked to various health conditions, including liver damage, high cholesterol, low birth weight, and chronic kidney disease. The study highlights the critical role of transitioning to electric vehicles in reducing carbon emissions while emphasizing the need to address new environmental challenges.
Jennifer Guelfo, an associate professor of environmental engineering at Texas Tech University and co-author of the study, emphasized the need for a balanced approach: “Slashing emissions with innovations like electric cars is critical, but it shouldn’t come with the side effect of increasing PFAS pollution.”
Due to their widespread use, the issue of PFAS in lithium-ion batteries is of global concern. Recent studies have detected low levels of PFAS in European and Chinese water supplies, although the sources of contamination were unclear until now. The study revealed that Bis-perfluoroalkyl sulfonimides (bis-FASIs), similar to older notorious chemicals like PFOA, are extremely difficult to degrade and have significant ecological impacts even at low concentrations.
Lee Ferguson, associate professor of environmental engineering at Duke University and co-author of the study, pointed out the lack of comprehensive research on the prevalence of these chemicals in lithium-ion batteries, making it challenging to assess the full scope of the issue.
The study conducted an extensive sampling campaign, collecting 75 surface water, 5 tap water, 2 groundwater, 1 snow, 15 sediment, and 21 soil samples from 87 different locations near manufacturing plants in Cottage Grove, Minnesota (USA); Paducah and Louisville, Kentucky (USA); Antwerp, Belgium; and Salindres, France, between January and October 2022.
In January 2022, field sampling was conducted in Cottage Grove, MN, near the 3M manufacturing facility. During this event, 13 surface water samples and 1 snow sample were collected. The historical PFAS production at this site has significantly contaminated nearby water bodies. The bis-FMeSI concentrations detected ranged from 2.04 to 440 ng/L, including 6.88 ng/L in the snow sample. Additionally, 15 other PFAS compounds were identified, with concentrations spanning from 1.10 ng/L (FBSA) to 3279 ng/L (PFBA).
A follow-up sampling event in June 2022 collected 24 water samples, 4 soil samples, and 4 sediment samples. Bis-FMeSI was detected in surface water at concentrations ranging from 1.12 to 2437 ng/L and in sediment and soil samples at concentrations up to 1626 ng/kg and 2300 ng/kg, respectively. These findings highlight both aqueous and atmospheric deposition of bis-FMeSI.
Similar comprehensive sampling in Paducah and Louisville, Kentucky; Antwerp, Belgium; and Salindres, France, revealed bis-FMeSI and other PFAS contaminants at various concentrations. In each location, surface water, soil, and sediment samples showed significant contamination levels, suggesting widespread environmental dispersion of these chemicals from manufacturing sites.
The study highlighted that most lithium-ion batteries end up in landfills, where they can leach PFAS into the environment. Only about 5% of these batteries are currently recycled, and by 2040, there could be around 8 million tons of lithium-ion battery waste.
To address this, scientists, engineers, manufacturers, and policymakers must collaborate on developing battery technologies and recycling solutions that do not exacerbate PFAS pollution.
Guelfo stressed the importance of preemptive evaluation: “We need to be carefully evaluating these chemicals that are being used in sustainable energy infrastructure. We should be evaluating them now before it becomes a more widespread problem. We have an opportunity to really maximize the idea of sustainability.”
The study highlighted several companies, including 3M, Solvay, and Arkema, which either hold patents for bis-FASIs or are involved in their production. In response to growing concerns, 3M has announced it will exit all PFAS manufacturing by the end of 2025, following a $10 billion settlement with US cities and towns over PFAS contamination in drinking water.
Additionally, the Environmental Protection Agency (EPA) has set stringent limits for PFAS in drinking water and is pushing for broader adoption of strategies to remove these chemicals. However, these regulations have ongoing legal challenges from chemical makers and water utilities.
