Synchrotron high-energy X-ray diffraction computed tomography has been employed to investigate, for the first time, commercial cylindrical Li-ion batteries electrochemically cycled over the two cycling rates of C/2 and C/20. This technique yields maps of the crystalline components and chemical species as a cross-section of the cell with high spatiotemporal resolution (550 × 550 images with 20 × 20 × 3 µm³ voxel size in ca. 1 h). The recently developed Direct Least-Squares Reconstruction algorithm is used to overcome the well-known parallax problem and led to accurate lattice parameter maps for the device cathode. Chemical heterogeneities are revealed at both electrodes and are attributed to uneven Li and current distributions in the cells. It is shown that this technique has the potential to become an invaluable diagnostic tool for real-world commercial batteries and for their characterization under operating conditions, leading to unique insights into “real” battery degradation mechanisms as they occur.

中文翻译：

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商用圆柱形锂离子电池中循环速率引起的空间分辨异质性

同步加速器高能 X 射线衍射计算机断层扫描已首次用于研究以 C/2 和 C/20 两种循环速率进行电化学循环的商用圆柱形锂离子电池。该技术以高时空分辨率（550 × 550 图像，20 × 20 × 3 µ m ³体素大小（约）1 小时）。最近开发的直接最小二乘重建算法用于克服众所周知的视差问题，并为器件阴极提供准确的晶格参数图。在两个电极上都显示出化学异质性，这归因于电池中的锂和电流分布不均匀。结果表明，该技术有可能成为现实世界商业电池及其在工作条件下表征的宝贵诊断工具，从而在“真实”电池退化机制发生时提供独特的见解。