In situ NMR of lithium ion batteries: bulk susceptibility effects and practical considerations.

The application of in situ nuclear magnetic resonance (NMR) to investigate batteries in real time (i.e., as they are cycling) provides fruitful insight into the electrochemical structural changes that occur in the battery. A major challenge for in situ static NMR spectroscopy of a battery is, however, to separate the resonances from the different components. Many resonances overlap and are broadened since spectra are acquired, to date, in static mode. Spectral analysis is also complicated by bulk magnetic susceptibility (BMS) effects. Here we describe some of the BMS effects that arise in lithium ion battery (LIB) materials and provide an outline of some of the practical considerations associated with the application of in situ NMR spectroscopy to study structural changes in energy materials.