Engineers in Texas have made a surprising discovery that could lead to longer-lasting and more reliable batteries—something that could benefit everything from smartphones to electric cars and large-scale renewable energy storage.
The breakthrough centers around a special protective layer that forms during battery use, helping smooth over the rough spots that typically wear batteries down over time.
When a battery is used, a thin layer forms on the metal part known as the anode.
This layer, called the solid-electrolyte interphase (SEI), helps the battery function, but it also creates uneven, rough surfaces.
Over time, this roughness can lead to performance issues, making batteries hold less charge and wear out faster.
The team of researchers from the University of Texas at Austin discovered a different kind of SEI—one that forms only temporarily during the discharge phase, when the battery is releasing energy.
This new version, called the transient solid-electrolyte interphase (T-SEI), appears briefly when the battery is working at high speeds, then dissolves and disappears once the battery rests.
What’s exciting is that this temporary layer leaves the battery’s surface smoother than before, which helps it stay efficient and last longer.
Stephen T. Fuller, a Ph.D. student and the study’s lead author, said the discovery could help design batteries that perform better under demanding conditions, avoid damage, and have longer life spans.
The research was recently published in the Proceedings of the National Academy of Sciences.
Most battery research has focused on the charging process—when a battery is refilled with energy.
But this new insight came from looking at the opposite: how batteries release energy during use.
Assistant professor Kent Zheng, who joined the university in 2023 and was recently named to Forbes’ 30 Under 30 list in science, said that the discharge process has been mostly ignored until now, even though it holds important clues for improving battery performance.
The team made their discovery using aqueous batteries, which are batteries that use a water-based solution to move ions back and forth during charging and discharging.
These types of batteries are seen as safer, more affordable, and more sustainable than traditional batteries, and they have strong potential for storing renewable energy like solar and wind power on a large scale.
The researchers used advanced tools to watch the T-SEI form and disappear in real time. This protective layer helped reduce the roughness of the battery surface by 42%, which is a big improvement.
Next, the researchers plan to explore whether this same helpful layer appears in other types of batteries. If it does, it could help prevent harmful structures called dendrites from forming—one of the main causes of battery failure.
