By turning button batteries on their side they can be studied by nuclear magnetic resonance without removing their metal casing
Researchers have recorded the first ever nuclear magnetic resonance (NMR) spectra of unmodified, off-the-shelf button batteries as they are charged and discharged. The metal battery casing had so far prevented such studies as it blocks the NMR radiofrequency field. But a team from Sandia National Laboratories, US, has found a way around this – simply turn the battery by 90°.