A group of researchers from Stanford University and the SLAC National Accelerator Laboratory may have discovered why smartphone batteries overheat and catch fire, according to a new research published in the journal Science.
In the study, the team used cryo-electron microscopy (cryo-EM) — a process where samples are flash-frozen in liquid nitrogen — to study lithium batteries. That then shed light on finger-like growths called dendrites, which can breach battery compartment barriers and cause both short circuits and fires.
The new process, which won the Nobel Prize in Chemistry this year, could give scientists a new way to look at molecules at the atomic scale, even when they are moving.
“This is super exciting and opens up amazing opportunities,” said lead author Yi Cui, a researcher from the National Accelerator Laboratory SLAC, in a statement. “With cryo-EM, you can look at a material that’s fragile and chemically unstable and you can preserve its pristine state – what it looks like in a real battery – and look at it under high resolution.”
To study these properties, the researchers looked at how lithium metal dendrites and their coatings reacted with various electrolytes. This showed that, while dendrites are crystalline when viewed at the atomic level, they form solid structures as they grow. In addition, scientists found that when they added a chemical known to improve performance to the coating, it became more orderly. That could then prevent dendrites and shut down potential overheating.
This is the first time researchers have been able to study dendrites as they form. As a result, the information in the study could help stop overheating and create safer batteries in the future.
However, there is still a long way to go. While the study is a step in the right direction, many more trials need to be run on the new process. If that goes well, it could then lead to huge technological advancements, such as electric cars that can go weeks on a single charge.
“We were really excited. said study co-author Yanbin Li, a researcher at Stanford University, according to Science Alert. “This was the first time we were able to get such detailed images of a dendrite, and we also saw the nanostructure of the SEI layer for the first time. This tool can help us understand what different electrolytes do and why certain ones work better than others.”