From electric cars to wireless earbuds, we rely on rechargeable batteries every day.
Most of these use liquid electrolytes, which help store and release energy quickly.
However, these liquids can catch fire if the battery is damaged or overheats, making them a safety risk.
Researchers at the University of Missouri are working on a solution. Assistant Professor Matthias Young and his team are developing solid-state batteries, which replace liquid electrolytes with solid materials.
These batteries have the potential to be safer and more efficient, but there’s a major challenge holding them back.
When a solid electrolyte touches the battery’s cathode (the part where electricity is stored and released), a very thin layer—about 100 nanometers thick—forms between them.
This layer blocks lithium ions from moving freely, which increases resistance and hurts the battery’s performance.
Scientists have struggled with this issue for more than a decade, but Young’s team made a big breakthrough in understanding the root cause.
Using four-dimensional scanning transmission electron microscopy (4D STEM), the researchers were able to examine the inside of the battery without taking it apart.
This cutting-edge technology allowed them to see, at the atomic level, how this unwanted layer forms and impacts the battery’s function.
Young’s lab specializes in creating thin protective coatings using a technique called oxidative molecular layer deposition (oMLD). Their next step is to test whether these coatings can prevent the unwanted reaction between the solid electrolyte and the cathode.
“The coatings need to be just the right thickness,” Young explained. “They have to stop the reaction but still allow lithium ions to move freely, so the battery keeps working efficiently.”
By carefully engineering these coatings at the nano-scale level, Young’s team hopes to make solid-state batteries work without performance loss. If successful, this technology could lead to safer, longer-lasting, and more powerful batteries for everything from smartphones to electric vehicles.
The study, published in Advanced Energy Materials, was co-authored by researchers Nikhila C. Paranamana, Andreas Werbrouck, Amit K. Datta, and Xiaoqing He at the University of Missouri.
