Rajh Ava, Vizintin Alen, Hoszowska Joanna, Dominko Robert, Kavčič Matjaž
Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
Faculty of Mathematics and Physics, University of Ljubljana, Jadranska Ulica 19, 1000 Ljubljana, Slovenia.
ACS Appl Energy Mater. 2024 Nov 20;7(23):11135-11143. doi: 10.1021/acsaem.4c02330. eCollection 2024 Dec 9.
In this work, sulfur X-ray emission measurements on a Li-S battery cathode were performed using a laboratory setup as an alternative to more common synchrotron radiation based absorption studies. Photoexcitation by an X-ray tube was used. Valence-to-core Kβ X-ray emission spectra were recorded with a wavelength dispersive crystal spectrometer in von Hamos geometry, providing excellent energy resolution and good detection efficiency. The setup was used to record S Kβ emission spectra from S cathodes from the Li-S battery and also under conditions. Average S oxidation state within the battery cathode during battery cycling was determined from the shape of the Kβ emission spectra. A more detailed S species characterization was performed by fitting a linear combination of previously measured laboratory synthesized standards to the measured spectra. Relative amounts of different S species in the cathode were determined during the cycling of the Li-S battery. The main advantage of X-ray emission spectroscopy is that it can be performed on concentrated samples with S loading comparable to a real battery. The approach shows great promise for routine laboratory analysis of electrochemical processes in Li-S batteries and other sulfur-based systems under conditions.
在这项工作中，使用实验室装置对锂硫电池阴极进行了硫X射线发射测量，以此作为更常见的基于同步辐射的吸收研究的替代方法。采用X射线管进行光激发。用波长色散晶体光谱仪在冯哈莫斯几何构型下记录价带至芯能级的Kβ X射线发射光谱，该光谱仪具有出色的能量分辨率和良好的检测效率。该装置用于记录锂硫电池硫阴极以及其他条件下的S Kβ发射光谱。通过Kβ发射光谱的形状确定电池循环过程中电池阴极内硫的平均氧化态。通过将先前测量的实验室合成标准品的线性组合拟合到测量光谱上，对硫物种进行了更详细的表征。在锂硫电池循环过程中确定了阴极中不同硫物种的相对含量。X射线发射光谱的主要优点是它可以在硫负载量与实际电池相当的浓缩样品上进行。该方法对于锂硫电池和其他条件下硫基系统中电化学过程的常规实验室分析显示出巨大的前景。
