On the Lithium Distribution in Halide Superionic Argyrodites by Halide Incorporation in Li7−xPS6−xClx
On the Lithium Distribution in Halide Superionic Argyrodites by Halide Incorporation in Li7−xPS6−xClx
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DOI：
10.26434/chemrxiv.14607411.v1
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发表时间：
2021-07
影响因子：
6.4
通讯作者：
A. Gautam;M. Ghidiu;E. Suard;Marvin A. Kraft;W. Zeier
中科院分区：
文献类型：
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作者：
A. Gautam;M. Ghidiu;E. Suard;Marvin A. Kraft;W. Zeier
超离子锂银矿作为全固态电池的固体电解质具有吸引力。这些组成为Li 6PS 5X（X = Cl、Br和I）的材料在X−/S2−位置之间表现出结构无序，无序度越高，Li+的传输就越好。进一步用氯阴离子取代硫化物（对于Li 7 − xPS 6 −xClx系列）已被证明可以增加离子电导率。然而，锂亚结构的潜在变化仍然相对未知。在这里，我们探索了一个更大的范围内的名义卤化物组成在这种材料中，从x = 0.25到x = 1.5，并探讨中子衍射和阻抗谱的变化。S2−被Cl−取代导致普遍存在的Li+“笼”中心的平均电荷降低，这反过来又导致与Li+离子的相互作用减弱。中子衍射数据的分析显示，Cl−含量的增加导致这些聚集的Li+“笼”变得更加相互连接，从而增加了Li+通过结构的导电性。本研究探讨的理解的基本结构，运输相关的argyrodites，特别是结构变化within在Li+离子的子结构后，改变阴离子电荷分布。
Superionic lithium argyrodites are attractive as solid electrolytes for all-solid-state-batteries. These materials of composition Li6PS5X (X = Cl, Br, and I) exhibit structural disorder between the X−/S2− positions, with higher disorder realizing better Li+ transport. Further replacement of the sulfide by chloride anions (for the series Li7−xPS6−xClx) has been shown to increase the ionic conductivity. However, the underlying changes to the lithium substructure are still relatively unknown. Here we explore a larger range of nominal halide compositions in this material from x = 0.25 to x = 1.5 and explore the changes with neutron diffraction and impedance spectroscopy. The replacement of S2− by Cl−causes a lowered average charge in the center of the prevalent Li+ “cages”, which in turn causes weaker interactions with Li+ ions. Analysis of neutron diffraction data reveals that the increased Cl− content causes these clustered Li+ “cages” to become more interconnected, thereby increasing Li+ conductivity through the structure. This study explores the understanding of the fundamental structure–transport correlations in the argyrodites, specifically structural changes withinthe Li+ ion substructure upon changing anionic charge distribution.