- The risk of contamination of soil and water from EV batteries is huge, if improperly disposed at the end of their lifespan.
- Batteries not only contain rare earth materials, but also have “forever chemicals” in their cathode and the electrolyte.
- Researchers at the UChicago Pritzker School of Molecular Engineering are designing a battery that doesn’t use these harmful chemicals in the first place.
The global demand for lithium-ion batteries is forecast to increase from 700 gigawatt-hours in 2022 to a whopping 4.7 terawatt-hours by 2030, according to Mckinsey & Company. That’s because battery usage is not just growing in electric vehicles, but also in electrical appliances, drones, grid-level energy storage and dozens of other applications. But their dirty secret of using harmful chemicals hasn’t been addressed yet.
In addition to rare earth materials in EV batteries and traction motors, these components also use dangerous chemicals called PFAS, which stands for per- and polyfluoroalkyl substances. They’re in everything, right from our clothes to the non-stick kitchen pans, according to the National Resources Defense Council. They don’t break down in the environment and can even infiltrate human bodies through food and water, hence the name “forever chemicals.”
Now researchers at the University of Chicago are designing next-generation EV batteries that don’t rely on PFAS. Both a cathode and the electrolyte in a typical lithium-ion battery have PFAS. They help in keeping the internal battery structure together. UChicago researchers said having PFAS in the cathode and the electrolyte is not a fundamental requirement. They claim to have a workaround that doesn’t affect performance.
“We are demanding more from our batteries. We want low-temperature performance. We want high-temperature performance. We want fast charging. We want lithium metal batteries. These are things that we are demanding as consumers,” Chibueze Amanchukwu, a professor at the UChicago Pritzker School of Molecular Engineering said in a blog post.
“What the scientific literature is doing now is to say, ‘Oh, let’s add more fluorinated components into the electrolyte.’ Almost all of those will be considered PFAS,” he said.
To address this issue, they developed a special “non-fluorinated solvent” free of PFAS for the electrolyte. That alone doesn’t solve the problem. The challenge is to prove that the material will at least match, or improve the performance of a typical EV battery.
Photo by: Mercedes-Benz
Turns out the cells free of PFAS demonstrated better ion-pairing, meaning they were more energy dense. They had more resistance to extreme temperatures, with the cycling apparently stable from 60 degrees Fahrenheit to -40 degrees. They also had better capacity retention, meaning the battery will not only last longer, but also continue to perform at a high level in the long term.
Of course, these batteries are in the lab experiment phase and nowhere near entering production. But the point of the study is to showcase that environmental concerns for EV batteries can be addressed right at the design stage.
When millions of end-of-life EV batteries enter the recycling and second-life phases by the end of the decade, the risk of them contaminating the environment is huge, especially if they’re not properly handled. PFAS has been linked to severe health hazards, including developmental effects in children and reproductive effects in women, according to the Environmental Protection Agency.
Right now, the global EV movement has adopted the move-fast-and-break-things approach prevalent among Silicon Valley tech giants. Being first to market is more important than resolving the potential damage EV batteries may cause years or decades later. Hopefully, with stricter regulations and solutions like these, future battery developments can take a more cautious and eco-friendly approach.
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