As shown previously, there is a tendency for composite electrodes to exhibit gradients in material utilisation due to diffuse transport limitations arising from slow diffusion of lithium ions; coupled with high toruosities from the carbon binder network, the material closest to the separator is more active than the material at the current collector surface, meaning that there is a spatial polarisation within the electrodes. Often, more lithium is extracted from the separator region and thus can reach a higher local potential. The volumetric strain distribution was analysed through the thickness of the electrode and showed a slight tendency for particles at the separator to undergo a larger volume expansion; however, this was established from only 15 particles in the electrode with an R 2 value of 0.49 hence is not a statistically significant result (see figure ). The size of the pristine particle may also play a role in the cracking behaviour as charging occurs; however, it was shown that the size of the particle had an insignificant effect on the volume expansion between pristine and 4.5 V, with no discernible trend (see figure ). Although, at higher C-rates, e.g., 2C, than that employed here (C/50), both sources of SoC heterogeneities (electrode thickness and particle diameter) may become more prominent. In the first instance, analysis was conducted on the particle including all crack voxels, but in addition, we report the crack volume subsequently segmented as a separate phase to the NMC material (i.e. NMC + crack, analysed separately). On average, the crack volume was approximately 9% of the total volume, with the largest amount of cracking occupying 16% of the total particle volume (see figure ). Additionally, the crack volume did not account for all of the absolute volume increase of each particle; in the best cases about 70% of the volume increase was associated with segmentable crack volume. However, the residual volume increase was not able to be accounted for at this resolution and can be assumed to be associated with fractures smaller than the 124 nm voxel resolution employed here. This phenomenon, known as partial averaging, occurs when voxels are occupied by two phases and thus NMC voxels that have a reduction in intensity due to the inclusion of void space. Due to the difference between the volume increase and the crack volume, it would appear that the NMC fraction of the particle had increased, but as discussed above we believe this to be due to unresolvable crack formation. We also see a higher proportion of cracking towards the centre of the particle that reduces in severity when tracking radially outwards towards the particle surface (see figure and). This is a feature noted previously with electrochemically induced cracking, as opposed to cracks that have been induced by the manufacturing process which tend to have a more random orientation. Again, the location of each particle was assessed in accordance with their cracking nature. Particles that reside closest to the current collector show a higher percentage of segmentable cracking with respect to the particle volume, thus suggesting that particles at the separator form larger void structures and particles at the current collector develop smaller cracks that are more evenly distributed, rather than a single large void in the centre of the particle with micro-cracks forming off this structure. This phenomenon may be explained by a lithium diffusion rate factor, where particles that are able to de-lithiate quickly, at the separator, go through intraparticle polarisation from the centre of the particle, and thus exhibit greater anisotropic mechanical stresses on the particles causing large void structures in the electrode, as shown previously with operando measurements on single particles. Conversely, particles at the current collector exhibit a more modest lithium diffusion rate and therefore do not have such an elevated level of polarisation within the particle, causing cracking to occur more homogeneously throughout the particle and therefore less likely to be segmented as a separate phase at the resolution used in these CT investigations. This observation is supported by previous electrochemo-mechanical and phase field modelling that also showed higher damage within secondary particles in the separator region. Another possible explanation for this might be the presence of residual stresses as described previously, where the greatest residual stresses may reside in the centre of the particles and correspond with the large central voids, although this wouldn't explain the prevalence of this phenomenon at the separator, unless a significant c-rate polarisation existed through the electrode thickness -this is a matter for future work.