Calpa Marcela, Nakajima Hiroshi, Mori Shigeo, Goto Yosuke, Mizuguchi Yoshikazu, Moriyoshi Chikako, Kuroiwa Yoshihiro, Rosero-Navarro Nataly Carolina, Miura Akira, Tadanaga Kiyoharu
Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan.
Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
Inorg Chem. 2021 May 17;60(10):6964-6970. doi: 10.1021/acs.inorgchem.1c00294. Epub 2021 Apr 29.
β-LiPS is a solid electrolyte with high Li conductivity, applicable to sulfide-based all-solid-state batteries. While a β-LiPS-synthesized by solid-state reaction forms only in a narrow 300-450 °C temperature range upon heating, β-LiPS is readily available by liquid-phase synthesis through low-temperature thermal decomposition of complexes composed of PS and various organic solvents. However, the conversion mechanism of β-LiPS from these complexes is not yet understood. Herein, we proposed the synthesis mechanism of β-LiPS from LiPS·acetonitrile (LiPS·ACN) and LiPS·1,2-dimethoxyethane (LiPS·DME), whose structural similarity with β-LiPS would reduce the nucleation barrier for the formation of β-LiPS. Synchrotron X-ray diffraction clarified that both complexes possess similar layered structures consisting of alternating LiPS and Li-ACN/DME layers. ACN/DME was removed from these complexes upon heating, and rotation of the PS tetrahedra induced a uniaxial compression to form the β-LiPS framework.
β-LiPS是一种具有高锂电导率的固体电解质，适用于硫化物基全固态电池。虽然通过固态反应合成的β-LiPS仅在加热时300-450°C的狭窄温度范围内形成，但通过由PS和各种有机溶剂组成的配合物的低温热分解，通过液相合成可以很容易地获得β-LiPS。然而，β-LiPS从这些配合物的转化机制尚未被理解。在此，我们提出了由LiPS·乙腈（LiPS·ACN）和LiPS·1,2-二甲氧基乙烷（LiPS·DME）合成β-LiPS的机制，它们与β-LiPS的结构相似性将降低β-LiPS形成的成核势垒。同步辐射X射线衍射表明，两种配合物都具有由交替的LiPS和Li-ACN/DME层组成的相似层状结构。加热时，ACN/DME从这些配合物中去除，PS四面体的旋转引起单轴压缩以形成β-LiPS骨架。
