Effect of tomography resolution on calculation of microstructural properties for lithium ion porous electrodes

Abstract

This work uses an open-source, data-driven, image-based modelling framework; OpenImpala. Lithium Iron Phosphate (LFP) electrode samples were imaged using micro-CT. Two scans were performed using the Zeiss 160 kVp Versa 510 at the University of Southampton. The two scans were both carried out on the same sample and using the same focal point, this is so they could be used as a direct comparison to see how porosity and tortuosity changed with spatial resolution. It is found that the Bruggeman correlation significantly underestimates the tortuosity compared to the OpenImpala calculated results. It is also found that there is a larger statistical variability in the 801 nm results, whereas the 400 nm results have a much smaller standard deviation. These results were compared to computer-generated images based on FIB/SEM tomographic data of a single Nickel Manganese Cobalt Oxide (NMC) porous active particle and found to have the same trends.