Meaning
Spatial resolution limits in computed tomography scanners create blurred voxels where multiple material phases occupy the same physical volume element. The partial volume effect causes these voxels to display an intermediate grayscale value that matches neither the solid nor the pore phase. This gray level blending makes simple thresholding inaccurate because it creates a false layer of material at the interface.
Sourcing teams must account for this distortion when evaluating supplier scan data.
Artifact Generation
Resolution limits make this artifact prominent when the voxel size is close to the thickness of the material features being imaged. During computed tomography scans, the partial volume effect occurs because the X-ray attenuation coefficient is averaged over the finite voxel volume. This averaging is problematic for thin polymer binders and carbon black networks, which often have dimensions below the scanner resolution.
As a result, the binder appears thicker and less dense than it is, which distorts the structural evaluation of the electrode. This distortion leads to incorrect estimates of the active surface area.
Mitigation Technique
Correcting this blurring requires higher imaging resolution or sub-voxel segmentation algorithms. Developers apply deconvolution methods to sharpen the phase boundaries and recover the true volume fractions. This ensures the digital models are accurate.
Sourcing Consequence
Procurement decisions depend on microstructural models that must not be corrupted by uncorrected scan data. If the partial volume effect is ignored, the calculated electrode porosity will be incorrect, which leads to poor electrolyte transport predictions. Sourcing contracts therefore specify the maximum voxel size allowed for scan submittals.
This requirement ensures that the data used to qualify suppliers is reliable.
