Gautam Ajay, Ghidiu Michael, Hansen Anna-Lena, Ohno Saneyuki, Zeier Wolfgang G
Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 17, D-35392 Giessen, Germany.
Institute for Applied Materials - Energy Storage Systems, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
Inorg Chem. 2021 Dec 20;60(24):18975-18980. doi: 10.1021/acs.inorgchem.1c02813. Epub 2021 Dec 1.
The lithium argyrodites LiPSX (X = Cl, Br, and I) have attracted interest as fast solid ionic conductors for solid-state batteries. Within this class of materials, it has been previously suggested that more polarizable anions and larger substituents should influence the ionic conductivity (e.g., substituting S by Se). Building upon this work, we explore the influence of Sn substitution in lithium argyrodites LiSnPSeI in direct comparison to the previously reported LiSnPSI series. The (P/Sn)Se polyhedral volume, unit cell volume, and lithium coordination tetrahedra Li(48)-(S/Se)-I increase with Sn substitution in this new selenide series. Impedance spectroscopy reveals that increasing Sn substitution results in a fivefold improvement in the ionic conductivity when compared to LiPSeI. This work provides further understanding of compositional influences for optimizing the ionic conductivity of solid electrolytes.
锂硫银锗矿LiPSX（X = Cl、Br和I）作为固态电池的快速固体离子导体已引起关注。在这类材料中，此前有人提出，极化率更高的阴离子和更大的取代基应会影响离子电导率（例如，用Se取代S）。基于这项工作，我们通过与先前报道的LiSnPSI系列直接比较，探索了Sn取代对锂硫银锗矿LiSnPSeI的影响。在这个新的硒化物系列中，(P/Sn)Se多面体体积、晶胞体积和锂配位四面体Li(48)-(S/Se)-I随Sn取代而增加。阻抗谱显示，与LiPSeI相比，增加Sn取代会使离子电导率提高五倍。这项工作为优化固体电解质离子电导率的成分影响提供了进一步的认识。
