Figure 4

7Li NMR spectra obtained for the battery-as-coil setup using a Hahn echo preparation (a) and for a reference battery cell using a traditional solenoid coil and single pulse acquisition (b). Due to limited excitation bandwidth, the spectra in (a) were obtained from two separate measurements, one where the spectrometer frequency was at 255Â ppm (left) and one where the spectrometer frequency was 5Â ppm (right).