As the need for the development of “beyond lithium” ion battery technologies continues unabated, lithium sulfur batteries have attracted widespread attention due to their very high theoretical energy density of 2600 W h kg⁻¹. However, despite much effort, the detailed reaction mechanism remains poorly understood. In this study, we have combined operando X-ray diffraction and X-ray microscopy along with X-ray tomography, to visualize the evolution of both the morphology and crystal structure of the materials during the entire battery cycling (discharging/charging) process. The dissolution and reformation of sulfur clusters is clearly observed during cycling. In addition, we demonstrate, for the first time, the critical role of current density and temperature in determining the size of both the resulting sulfur clusters and Li₂S particles. This study provides new insights about promising avenues for the continued development of lithium sulfur batteries, which we believe may lead to their broad deployment and application.

中文翻译：

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硫正极的直接可视化：通过基于操作 X 射线的方法对锂硫电池的新见解†

^{随着“超越锂”离子电池技术发展的需求持续有增无减，锂硫电池因其2600 Wh kg -1}的极高理论能量密度而受到广泛关注。然而，尽管付出了很多努力，但详细的反应机制仍然知之甚少。在这项研究中，我们结合了操作数X 射线衍射和 X 射线显微镜以及 X 射线断层扫描，以可视化整个电池循环（放电/充电）过程中材料的形态和晶体结构的演变。在循环过程中清楚地观察到硫簇的溶解和重新形成。此外，我们首次证明了电流密度和温度在确定生成的硫簇和 Li ₂ S 颗粒尺寸方面的关键作用。这项研究为锂硫电池的持续发展提供了新的见解，我们认为这可能会导致它们的广泛部署和应用。