Researchers at Purdue University in Indiana and Argonne National Laboratory in Illinois were recently on a team led by the Georgia Institute of Technology to get a look at what happens inside solid-state lithium batteries. They used X-ray tomography — which creates a 3D computer model — to watch what happens to materials inside the batteries as they charge and discharge.
The commonly used lithium-ion batteries that power everything from handheld electronic devices to electric vehicles use a liquid electrolyte to carry ions back and forth to the battery electrodes during charging and discharging. Solid-state battery technology uses a solid electrolyte that improves future battery safety and energy density.
But solid-state battery technology so far does not provide comparable product life to the lithium-ion versions. Solid-state batteries are not expected to become pervasive until they achieve longer lifetimes. The research team peeked inside solid-state batteries to identify a potential holdback to longer lifetimes.
- The researchers discovered that the battery operation caused voids to form where the lithium meets a solid electrolyte. That causes a loss of contact, which is a leading cause of battery failure.
- Limitations with the testing resulted in the researchers only observing the batteries’ inner workings for one cycle. They strive for future work that observes multiple cycles and whether the battery structure over time might adapt to the voids at the lithium/solid electrolyte interface.
- The scientists believe this study can help design better interfaces to advance solid-state battery development. “We are very excited about the technological prospects for solid-state batteries,” said Matthew McDowell, assistant professor at Georgia Tech, in a news release. “There is substantial commercial and scientific interest in this area, and information from this study should help advance this technology toward broad commercial applications.”