Diagnosing a dud may lead to a better battery

(Press-News.org) It’s (going to be) electric.

But how soon? How quickly our society can maximize the benefit of electrification hinges on finding cheaper, higher performance batteries — a reality closer to hand through new research from Virginia Tech.

A team of chemists led by Feng Lin and Louis Madsen found a way to see into battery interfaces, which are tight, tricky spots buried deep inside the cell. The research findings were published on April 1 in the journal Nature Nanotechnology.

“There are major, longstanding challenges at the interfaces,” said Jungki Min, a chemistry graduate student and the study’s first author. “We are always trying to gain better control over these buried surfaces.”

The team member’s discovery of a new imaging technique that enabled them to peer inside an operating battery happened by chance. They were originally looking at a new formulation of electrolyte material. 

The best battery batter Sandwiched between the negative and positive electrodes, the electrolyte is the filling that carries charged particles, called ions, back and forth to charge and discharge a battery.

Electrolytes have many possible component combinations involving salts, solvents, and additives. They can be liquid, solid, gel-like, or even multiphase, which means that the material can shift from rigid to flexible depending on the conditions.

But what’s the best material to use for the critical task of ferrying charge?

That’s one of the big questions in science right now, and it is key to developing high-energy batteries with longer lifespans that can be stable at extreme temperatures — all important qualities for the next generation of electric vehicles, electric appliances, and other battery-powered technologies such as artificial intelligence.

Where energy goes to disappear To answer this question, Lin and Madsen have been looking at something called a multiphase polymer electrolyte, which has the potential to store more energy in the same size battery, along with being safer and cheaper than conventional batteries.

Madsen’s lab discovered a multiphase electrolyte, called a molecular ionic composite, in 2015. Madsen’s and Lin’s research groups have been working together to build lithium and sodium batteries based on this formulation, and they have been making consistent improvements.

But there are a few caveats: The batteries are plagued with weird growths and unhelpful behaviors that sprout up where the electrolyte and the electrodes come together at that Bermuda Triangle of batteries, the interfaces.

Insight at the interfaces To catch a glimpse of what was causing the spazzy interface behavior, Min took many trips to Brookhaven National Laboratory over the past few years.

Brookhaven’s tender energy X-ray beam line is heavily used to analyze things such as meteorites and fungi. But no one had ever used it to look at polymer electrolytes.

What researchers found, combined with results from other imaging techniques, allowed then to pinpoint the source of the problems: Part of the architectural support system degraded as the battery cycled, leading to eventual failure.

But it’s more than just a simple diagnosis.

From here on out, researchers can use this technique to finally see both the intricate structure and the chemical reactions of the buried interfaces.

“This has been a great collaboration between multiple research laboratories across the country,” said Lin, who is a Leo and Melva Harris Faculty Fellow. “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 Boise State University, University of Pennsylvania, and Brookhaven National Laboratory.

The work was primarily supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy. Part of the work was also supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy through the Advanced Battery Materials Research Program (Battery500 Consortium). Seedling support was provided through the Virginia Tech College of Science Strategic Initiative in Energy with resources from the Virginia Tech Nanoscale Characterization and Fabrication Laboratory.

Original Study DOI: 10.1038/s41565-025-01885-5

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