Optically‐Coupled X‐Ray Computed Laminography System for High‐Speed Inspection of Lithium‐Ion Batteries

Abstract Conventional X‐ray computed tomography systems for microstructure inspection typically employ a geometrically magnified imaging setup, requiring a micro‐focus X‐ray source to mitigate image blurring caused by a finite focal spot size. However, due to its low output power, the micro‐focus X‐ray source results in prolonged image acquisition times. This study presents a novel optically‐coupled X‐ray computed laminography system for high‐speed inspection. In the proposed system, a scintillator is placed in contact with an object, effectively minimizing image blurring despite the use of an X‐ray source with a large focal spot. Consequently, a high‐power X‐ray tube can be employed without compromising spatial resolution, leading to a significant reduction in scan time. Modulation transfer function analysis confirms that a spatial resolution of 38 µm is achieved using a high‐power (400 W) X‐ray tube with a 400 µm focal spot. In addition, high‐quality 3D imaging of lithium‐ion batteries (LIBs) is demonstrated with a scan time as low as 2 s and a contrast‐to‐noise ratio exceeding 3. By overcoming the trade‐off between the spatial resolution and the scan time in X‐ray imaging, the proposed system enables high‐throughput in‐line inspection of mass‐produced LIBs.