ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
0/0

Changing the Static and Dynamic Lattice Effects for the Improvement of the Ionic Transport Properties Within the Argyrodite Li6PS5-xSexI

preprint
revised on 01.10.2019 and posted on 02.10.2019 by Roman Schlem, Michael Ghidiu, Sean Culver, Anna-Lena Hansen, Wolfgang Zeier

The lithium argyrodites Li6PS5X (X = Cl, Br, I) have been gaining momentum as candidates for electrolytes in all-solid-state batteries. While these materials have been well-characterized structurally, the influences of the static and dynamic lattice properties are not fully understood. Recent improvements to the ionic conductivity of Li6PS5I (which as a parent compound is a poor ionic conductor) via elemental substitutions have shown that a multitude of influences affect the ionic transport in the lithium argyrodites, and that even poor conductors in this class have room left for improvement.

Here we explore the influence of isoelectronic substitution of sulfur with selenium in Li6PS5-xSexI. Using a combination of X-ray diffraction, impedance spectroscopy, Raman spectroscopy, and pulse-echo speed of sound measurements,we explore the influence of the static and dynamic lattice on the ionic transport. The substitution of S2-with Se2- broadens the diffusion pathways and structural bottlenecks, as well as leading to a softer more polarizable lattice, all of which lower the activation barrier and lead to an increase in the ionic conductivity. This work sheds light on ways to systematically understand and improve the functional properties of this exciting material family.

Funding

Bundesministerium für Bildung und Forschung 03XP0177A

Bundesministerium für Bildung und Forschung 03XP0176A

History

Email Address of Submitting Author

wolfgang.g.zeier@pc.jlug.de

Institution

Justus-Liebig-University Giessen

Country

Germany

ORCID For Submitting Author

0000-0001-7749-5089

Declaration of Conflict of Interest

none

Exports

Logo branding

Categories

Exports