Spatially resolved characterization of the porous structure of lead-acid battery plates after operation using micro-computed tomography

Abstract

Micro-computed tomography is a powerful non-destructive analytical technique that is used in a variety of research fields including material and battery science. This technique was used to analyze SLI lead acid plates at different states of charge (SoC) and UPS AGM battery plates at different states of health (SoH). The SLI plates were found to have no discernable macro porosity differences at different SoC along with minimal visual changes. The UPS AGM battery plates varying in SoH were found to have significantly varying porosity over the geometric plate dimensions but also over the grid mesh dimensions and plate depth. The sulphation observed on the negative plates that most probably contributed to a decrease in capacity was confirmed by X-ray diffraction analysis. All analyzed samples showed a positively skewed pore size distribution. Micro-computed tomography is a technique that allows for spatial resolving of the lead acid plates to further explore their porosity nature.