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

## TL;DR

A new X-ray system enables fast, high-resolution imaging of lithium-ion batteries without sacrificing speed.

## Contribution

An optically-coupled X-ray system decouples spatial resolution from focal spot size, enabling high-speed inspection.

## Key findings

- A spatial resolution of 38 µm is achieved using a high-power X-ray tube with a 400 µm focal spot.
- 3D imaging of lithium-ion batteries is demonstrated with a scan time as low as 2 seconds.
- The system enables high-throughput in-line inspection of mass-produced 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.

This study presents an optically coupled X‐ray computed laminography system for high‐speed inspection of lithium‐ion batteries. A scintillator serving as a virtual detector decouples spatial resolution from the X‐ray focal spot size, enabling defect detection even with large‐spot, high‐power X‐ray tubes. This design achieves rapid 3D imaging and in‐line identification of fine internal defects within seconds.