Ivan Racheff Professor Rosa Espinosa Marzal has received a $556,000 NSF grant to investigate the solid electrolyte interphase — a nanoscale protective coating that governs battery safety, lifespan and performance — in next-generation sodium- and potassium-based batteries. Using atomic force microscopy, infrared spectroscopy and computational modeling, her team aims to decode how this poorly understood layer forms and behaves, with findings expected to inform the design of safer, longer-lasting and more affordable energy storage systems.
Written by Jackson Brunner
Ivan Racheff Professor Rosa Espinosa Marzal of the Departments of Materials Science and Engineering and Department of Civil and Environmental Engineering at The Grainger College of Engineering, University of Illinois Urbana-Champaign, has received a $556,000 grant from the U.S. National Science Foundation to investigate a critical — and poorly understood — layer that forms inside batteries and governs their safety, lifespan, and performance.
Pictured: Ivan Racheff Professor Rosa Espinosa Marzal
Why it matters:As lithium-based batteries approach their performance ceiling, the race is on to develop alternatives using more abundant elements like sodium and potassium. A key obstacle is that scientists don't yet fully understand how a microscopic protective coating — called the solid electrolyte interphase, or SEI — forms inside these next-generation batteries.
What they'll do:Espinosa Marzal's team will study highly concentrated "water-in-salt" electrolytes using a combination of laboratory experiments and computational modeling to map how the SEI forms, evolves, and behaves at the nanoscale.
The three-year project runs from Feb. 15, 2026 through Jan. 31, 2029.
Researchers will use advanced techniques including atomic force microscopy and infrared spectroscopy to observe SEI formation in real time.
The work will also explore hybrid electrolyte mixtures that incorporate ionic liquids, which could offer new ways to fine-tune battery performance.
"The solid electrolyte interphase is one of the most consequential — and least understood — components in a battery system. What happens at that electrode surface at the nanoscale determineseverything from how long a battery lasts to how safely it operates. This project gives us the tools and the focus to finally get at those fundamental mechanisms, and to do it in electrolyte systems that could power the next generation of energy storage technology." - Rosa Espinosa Marzal, professor, Department of Materials Science and Engineering and Department of Civil and Environmental Engineering
The big picture:The SEI layer acts like a gatekeeper — it needs to be chemically stable, electrically insulating, and capable of allowing ions to pass through freely. Getting that balance right is essential for batteries that are safer, longer-lasting, and cheaper to produce.
What's next:Results from this work are expected to inform the design of future battery systems and contribute to broader advances in materials and electrochemical science. The project will also train two graduate students and engage undergraduates in research, supporting the next generation of STEM talent.