Strauss Florian, Lin Jing, Karger Leonhard, Weber Daniel, Brezesinski Torsten
Battery and Electrochemistry Laboratory (BELLA), Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
Inorg Chem. 2022 Apr 18;61(15):5885-5890. doi: 10.1021/acs.inorgchem.2c00260. Epub 2022 Apr 6.
In search of high-performance solid electrolytes, various materials have been discovered in the past, approaching or even exceeding the ionic conductivity of conventional liquid electrolytes. Among the reported classes of superionic electrolytes for solid-state battery applications, lithium thiophosphates appear to be the most promising owing to their high ionic conductivity and mechanical softness. A recent example is the LiPSI phase (4/). Surprisingly, this material shows a comparatively low ionic conductivity at room temperature ranging from 10 to 10 S cm despite having favorable structural characteristics. Because of discrepancies between experiment and theory regarding the Li-ion conductivity and polymorphism in LiPSI, we herein examine the crystal structure over a broad temperature range using and X-ray and neutron powder diffraction techniques. We demonstrate the absence of polymorphic transitions, with a lithium redistribution at low temperatures though, and confirm the relatively poor room-temperature ionic conductivity despite the presence of a three-dimensional (3D) percolation network for facile charge transport.
为了寻找高性能固体电解质，过去已经发现了各种材料，其离子电导率接近甚至超过传统液体电解质。在报道的用于固态电池应用的超离子电解质类别中，硫代磷酸锂因其高离子电导率和机械柔软性而似乎最具前景。最近的一个例子是LiPSI相（4/）。令人惊讶的是，尽管该材料具有良好的结构特性，但在室温下其离子电导率相对较低，范围为10至10 S/cm。由于在LiPSI中锂离子电导率和多晶型方面实验与理论存在差异，我们在此使用X射线和中子粉末衍射技术在较宽温度范围内研究其晶体结构。我们证明不存在多晶型转变，不过在低温下存在锂的重新分布，并证实尽管存在便于电荷传输的三维（3D）渗流网络，但室温离子电导率相对较差。
