Geometric Changes in Cylindrical Batteries as a Function of State of Charge

Abstract

High-resolution, high-throughput CT scanning of commercial lithium-ion and sodium-ion cylindrical batteries provides quantitative detail into subtle geometrical changes occurring as a function of state-of-charge. Precise quantification via computer vision algorithms reveals a core area change with reversible and irreversible components in EVE lithium-ion cells, hysteresis in can eccentricity in Samsung lithium-ion cells, and the absence of significant geometrical changes in HAKADI sodium-ion cells. The difference in metrics between charge and discharge is introduced to remove the influence of tabs. The results demonstrate the potential of CT as a quasi-in-situ imaging technique for capturing sensitive geometric changes during cycling.