Why would you want to see inside a battery? To monitor the changes inside that could compromise it, in order to figure out methods of prevention. This is why a team at New York University has used MRI to get a detailed look inside lithium-ion batteries.
"One particular challenge we wanted to solve was to make the measurements 3D and sufficiently fast, so that they could be done during the battery-charging cycle," said senior author Alexej Jerschow. "This was made possible by using intrinsic amplification processes, which allow one to measure small features within the cell to diagnose common battery failure mechanisms. We believe these methods could become important techniques for the development of better batteries."
When a lithium-ion battery charges, it builds up deposits, or dendrites. Over time, these can affect the battery's performance and become a safety hazard. The same team had previously used MRI to monitor this dendrite growth by looking at it directly, but with limited resolution. This new method uses MRI to look at the electrolytes around the lithium. Because the electrolytes become distorted around the dendrites, the technique allowed an ultra-fast, very detailed 3D model to be constructed.
The full study can be found online, published today in the journal PNAS.