Multimodal Characterization of Coating Defects in Graphite Electrodes for Lithium-Ion Batteries

The quality of lithium-ion battery (LIB) electrodes is critical to ensuring optimal performance, safety, and lifespan. Defects in graphite electrodes, such as cracks, agglomeration, and coating inhomogeneity, can severely impact battery performance by disrupting ion transport, promoting inactive lithium formation, and posing safety risks. In this study, we investigate coating defects in graphite electrodes and their influence on electrochemical performance. Among the observed defects, surface cracks were found to cause the most severe capacity degradation, likely due to local thickness variations and lithium accumulation at exposed copper sites. To enable comprehensive defect detection, we propose a multimodal characterization approach that integrates optical imaging, infrared thermography, and X-ray radiography. This strategy combines surface, thermal, and volumetric information, allowing for reliable, in-line assessment of coating uniformity and defect severity, and offering practical guidance for improving electrode manufacturing quality control.