a shows horizontal and vertical orthogonal slices out of the X-ray tomograms. In total, 103 tomograms were recorded labelled from CR2-000 to CR2-102. One tomogram was recorded every 40 s with a total acquisition period of 2.8 s. Here the pristine state and two partly discharged states are presented. The images show the cracking and volume expansion of the MnO2 electrode during cell discharging. The highly absorbing steel casing is visible as very bright ring around the wounded membrane–electrode ensemble. The contrast was optimised in order to improve the contrast within the lower attenuating components. b shows orthogonal slices of the neutron tomogram captured during the discharge over a 4.7 Ω resistor, where the lithium electrode and the excess of electrolyte in the middle of the cell are clearly visible. Lithium intercalation and electrolyte consumption are observed, as well as electrode cracking and electrolyte consumption. In total, eight neutron tomograms were collected with an acquisition period of about 8 h. The discharging process was interrupted for each tomogram and labelled with CR2-00 from the pristine to CR2-07, the fully discharged SoC.