Advanced Operando Analaysis for Interface Observation uinsg Synchrotron X-Ray Computed Tomography for Lead-Acid Batteries

In the realm of battery technology, a field that has profoundly influenced various industries, including the automotive sector with the widespread adoption of lithium-ion batteries (LIBs), trust in these energy storage solutions remains challenged by issues related to safety, cost, and environmental impact. This has ignited an ongoing competition between traditional and emerging battery technologies.<br/>Lead acid batteries (LABs), a technology dating back to 1859, have endured as preferred secondary power sources in many applications, primarily due to their economic advantages. Nevertheless, LABs face significant hurdles in order to compete effectively with other battery types. Deep discharges can lead to rapid sulfation, while the irreversible crystallization of lead sulfate (PbSO4) can compromise battery lifespan and performance. Therefore, understanding the structural transformations of two critical components, the positive active material (PAM) and negative active material (NAM), becomes imperative for enhancing battery capacity and cycle life. Variations in internal morphology can influence electrode porosity and surface area, both pivotal factors in determining battery performance. Traditional post-mortem analysis methods, such as scanning and transmission electron microscopy (SEM and TEM), fall short in capturing real-time changes during cycling.<br/>Synchrotron X-ray computed tomography (XCT) emerges as a non-destructive methodology for characterizing material morphology and interfaces across a wide spectrum of scales, from sub-micron to centimeters. This technique facilitates both two-dimensional (2D) and three-dimensional (3D) visualization, proving invaluable for investigating interface transformations in solid-phase materials. In situ or operando measurements enable the identification of morphology changes due to phase transitions during cycling. XCT-generated images can be reconstructed into 2D slices and further assembled into 3D representations, aiding in the interpretation of porosity and particle evolution across different states of charge (SOC). Additionally, complementary synchrotron X-ray techniques, such as diffraction (XRD) and transmission X-ray microscopy (TXM), contribute to unveiling the intrinsic chemo-mechanical dynamics within lead-acid batteries.<br/>This presentation promises to shed light on LABs, offering insights into their mechanism through various synchrotron X-ray techniques. The application of in situ and operando X-ray measurements enhances our understanding of LABs, contributing to broader comprehension of this enduring energy storage technology.