XRD-CT measurements XRD-CT measurements were performed at beamline ID31 of the ESRF using a 95 keV (λ = 0.130509 Å) monochromatic X-ray beam focused to have a spot size of ca. 25 × 4 μm (Horizontal x Vertical). 2D powder diffraction patterns were acquired using the Pilatus3 X CdTe 2 M hybrid photon counting area detector. The battery was mounted onto a goniometer which was placed on a rotation stage (Figure ) itself mounted on top of a translation stage. The sample-to-detector distance was approximately 1 m. The XRD-CT scans were measured by performing a series of zigzag line scans using the interlaced approach . An exposure time of 10 ms and an angular range of 0-180° with 400 projections in total were used for each XRD-CT dataset. Four interlaced XRD-CT subsets were collected, each with 100 projections covering an angular range of 0-180° using the same angular step size and a different starting angle. The fast axis was the translation axis (fly scanning) and slow axis was the rotation axis. For each interlaced zigzag XRD-CT scan a translation step size of 30 microns was applied ; in total 637 translation steps were made per line scans corresponding to a covered area of 19.11 × 19.11 mm 2 . The detector calibration was performed using a CeO2 standard (Figure ). Every 2D diffraction image was calibrated and azimuthally integrated to a 1D powder diffraction pattern with a 20 % trimmed mean filter using the pyFAI software package and in-house developed scripts . The integrated diffraction patterns were reshaped into sinograms and centered; the air scatter signal was subtracted from the data. The XRD-CT images were initially reconstructed using the filtered back projection algorithm in MATLAB. The voxel size in the reconstructed images corresponded to 30 × 30 × 4 μm 3 . To further illustrate the chemical gradients present in the XRD-CT data, images-of-interest were converted from cartesian to polar coordinates using inhouse MATLAB developed scripts. This approach enables the virtual unrolling of the battery cell jelly-roll providing means to capture gradients as a function of the battery radius 59 .