Guida Dominick P, Stavola Alyssa M, Chuang Andrew Chihpin, Okasinski John S, Wendling Matthew T, Chadderdon Xiaotong H, Gallaway Joshua W
Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States of America.
Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave, Lemont, Illinois 60439, United States of America.
ACS Meas Sci Au. 2023 Jun 21;3(5):344-354. doi: 10.1021/acsmeasuresciau.3c00015. eCollection 2023 Oct 18.
High-resolution X-ray computed tomography (CT) has become an invaluable tool in battery research for its ability to probe phase distributions in sealed samples. The Cartesian coordinates used in describing the CT image stack are not appropriate for understanding radial dependencies, like that seen in bobbin-type batteries. The most prominent of these bobbin-type batteries is alkaline Zn-MnO, which dominates the primary battery market. To understand material radial dependencies within these batteries, a method is presented to approximate the Cartesian coordinates of CT data into pseudo-cylindrical coordinates. This is important because radial volume fractions are the output of computational battery models, and this will allow the correlation of a battery model to CT data. A selection of 10 anodes inside Zn-MnO AA batteries are used to demonstrate the method. For these, the pseudo-radius is defined as the relative distance in the anode between the central current collecting pin and the separator. Using these anodes, we validate that this method results in averaged one-dimensional material profiles that, when compared to other methods, show a better quantitative match to individual local slices of the anodes in the polar θ-direction. The other methods tested are methods that average to an absolute center point based on either the pin or the separator. The pseudo-cylindrical method also corrects for slight asymmetries observed in bobbin-type batteries because the pin is often slightly off-center and the separator often has a noncircular shape.
高分辨率X射线计算机断层扫描（CT）因其能够探测密封样品中的相分布，已成为电池研究中一项非常重要的工具。用于描述CT图像堆栈的笛卡尔坐标并不适合理解径向相关性，例如在筒式电池中所见到的那种。这些筒式电池中最突出的是碱性锌锰电池，它在一次电池市场中占据主导地位。为了理解这些电池内部材料的径向相关性，本文提出了一种方法，将CT数据的笛卡尔坐标近似转换为伪圆柱坐标。这很重要，因为径向体积分数是计算电池模型的输出结果，这将使得电池模型能够与CT数据建立关联。我们使用锌锰AA电池内部的10个阳极来演示该方法。对于这些阳极，伪半径被定义为阳极中集流中心引脚与隔膜之间的相对距离。通过使用这些阳极，我们验证了该方法能够得到平均的一维材料剖面图，与其他方法相比，在极角θ方向上，该剖面图与阳极的各个局部切片在定量上具有更好的匹配度。所测试的其他方法是基于引脚或隔膜平均到绝对中心点的方法。伪圆柱方法还校正了筒式电池中观察到的轻微不对称性，因为引脚往往略微偏离中心，且隔膜通常具有非圆形形状。
