A team of chemists led by Feng Lin and Louis Madsen from Virginia Tech discovered a way to see into battery interfaces, which are tight, difficult regions deep inside the cell. The study’s findings were published on April 1st, 2025, in Nature Nanotechnology.
Jungki Min, a chemistry graduate student working with Professor Feng Lin. Image Credit: Spencer Coppage for Virginia Tech.
According to recent Virginia Tech research, how quickly humanity can reap the benefits of electrification is dependent on discovering cheaper, higher-performance batteries, which is becoming more feasible.
There are major, longstanding challenges at the interfaces. We are always trying to gain better control over these buried surfaces.
Jungki Min, Study First Author and Graduate Student, Virginia Tech
By coincidence, one of the team members discovered a new imaging technology that allowed them to see into an operating battery. Initially, they were looking at a new electrolyte formulation.
The Best Battery Batter
The electrolyte, which is sandwiched between the negative and positive electrodes, is the filling that transports charged particles known as ions back and forth to charge and discharge batteries.
Electrolytes can be made up of various salt, solvent, and additive combinations. They can be liquid, solid, gel-like, or multiphase, implying that the material can change from hard to flexible depending on the conditions.
But what material is most suited for the essential role of ferrying charge?
That is one of the most pressing questions in science right now, and it is critical to developing high-energy batteries with longer lifespans and the ability to remain stable at extreme temperatures — all of which are required for the next generation of electric vehicles, electric appliances, and other battery-powered technologies like artificial intelligence.
Where Energy Goes to Disappear
Lin and Madsen have been researching a multiphase polymer electrolyte, which has the potential to store more energy in the same size battery while still being safer and less expensive than traditional batteries.
Madsen's lab created a multiphase electrolyte known as a molecular ionic composite in 2015. Madsen and Lin's research groups have been working together to develop lithium and sodium batteries based on this formulation, and they have made steady progress.
However, there are a few caveats: The batteries are troubled by strange growths and unhelpful behaviors that sprout up where the electrolyte and electrodes meet at the interfaces, which are the Bermuda Triangle of batteries.
Insight at the Interfaces
Min visited Brookhaven National Laboratory several times in recent years to better understand what was generating the spazzy interface behavior.
Brookhaven's tender energy X-ray beamline is widely utilized to study meteorites and fungi. However, no one has previously used it to examine polymer electrolytes.
The researchers' discoveries, together with results from other imaging techniques, enabled them to pinpoint the source of the problems: a component of the architectural support system weakened as the battery cycled, eventually leading to failure.
But this is not just a simple diagnosis.
From now on, researchers can utilize this approach to view both the detailed structure and chemical reactions of the buried interfaces.
Lin added, “This has been a great collaboration between multiple research laboratories across the country. We now have a good mechanistic picture to guide us for a better design of interfaces and interphases in solid polymer batteries.”
Study Collaborators Include:
Researchers from Brookhaven National Laboratory, the University of Pennsylvania, and Boise State University.
The Office of Energy Efficiency and Renewable Energy at the US Department of Energy provided the majority of the study's funding. Through the Advanced Battery Materials Research Program (Battery500 Consortium), the U.S. Department of Energy's Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies, also provided assistance for a part of the work.
Using resources from the Virginia Tech Nanoscale Characterization and Fabrication Laboratory, the Virginia Tech College of Science Strategic Initiative in Energy offered seedling support.
Journal Reference:
Min, J., et al. (2025) Investigating the effect of heterogeneities across the electrode|multiphase polymer electrolyte interfaces in high-potential lithium batteries. Nature Nanotechnology. doi.org/10.1038/s41565-025-01885-5.