Further Evidence for Energy Landscape Flattening in the Superionic Argyrodites Li6+ xP1- xMxS5I (M = Si, Ge, Sn)

Saneyuki Ohno, Bianca Helm, Till Fuchs, Georg Dewald, Marvin A. Kraft, Sean P. Culver, Anatoliy Senyshyn, Wolfgang G. Zeier

研究成果: Contribution to journalArticle査読

25 被引用数 (Scopus)

抄録

All-solid-state batteries are promising candidates for next-generation energy-storage devices. Although the list of candidate materials for solid electrolytes has grown in the past decade, there are still many open questions concerning the mechanisms behind ionic migration in materials. In particular, the lithium thiophosphate family of materials has shown very promising properties for solid-state battery applications. Recently, the Ge-substituted Li6PS5I argyrodite was shown to be a very fast Li-ion conductor, despite the poor ionic conductivity of the unsubstituted Li6PS5I. Therein, the conductivity was enhanced by more than 3 orders of magnitude due to the emergence of I-/S2- exchange, i.e., site disorder, which led to a sudden decrease of the activation barrier with a concurrent flattening of the energy landscapes. Inspired by this work, two series of elemental substitutions in Li6+xP1-xMxS5I (M = Si and Sn) were investigated in this study and compared to the Ge analogue. A sharp reduction in the activation energy was observed at the same M4+/P5+ composition as previously found in the Ge analogue, suggesting a more general mechanism at play. Furthermore, structural analyses with X-ray and neutron diffraction indicate that similar changes in the Li sublattice occur despite a significant variation in the size of the substituents, suggesting that in the argyrodites the lithium substructure is most likely influenced by the occurring Li+-Li+ interactions. This work provides further evidence that the energy landscape of ionic conductors can be tailored by inducing local disorder.

本文言語英語
ページ(範囲)4936-4944
ページ数9
ジャーナルChemistry of Materials
31
13
DOI
出版ステータス出版済み - 7 9 2019
外部発表はい

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

フィンガープリント 「Further Evidence for Energy Landscape Flattening in the Superionic Argyrodites Li<sub>6+ x</sub>P<sub>1- x</sub>M<sub>x</sub>S<sub>5</sub>I (M = Si, Ge, Sn)」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

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