Journal article

Publication year: 2020

Pages: 21210-21219

Journal: Journal of the American Chemical Society

Volume number: 142

Issue number: 50

ISSN: 0002-7863

eISSN: 1520-5126

Open access status: Hybrid

DOI Link: https://doi.org/10.1021/jacs.0c10735

Publisher: American Chemical Society

Abstract: 
Strategies to enhance ionic conductivities in solid electrolytes typically focus on the effects of modifying their crystal structures or of tuning mobile-ion stoichiometries. A less-explored approach is to modulate the chemical bonding interactions within a material to promote fast lithium-ion diffusion. Recently, the idea of a solid-electrolyte inductive effect has been proposed, whereby changes in bonding within the solid-electrolyte host framework modify the potential energy landscape for the mobile ions, resulting in an enhanced ionic conductivity. Direct evidence for a solid-electrolyte inductive effect, however, is lacking-in part because of the challenge of quantifying changes in local bonding interactions within a solid-electrolyte host framework. Here, we consider the evidence for a solid-electrolyte inductive effect in the archetypal superionic lithium-ion conductor Li10Ge1-xSnxP2S12. Substituting Ge for Sn weakens the {Ge,Sn}-S(2-)bonding interactions and increases the charge density associated with the S2- ions. This charge redistribution modifies the Li+ substructure causing Li+ ions to bind more strongly to the host framework S2- anions, which in turn modulates the Li+ ion potential energy surface, increasing local barriers for Li+ ion diffusion. Each of these effects is consistent with the predictions of the solid-electrolyte inductive effect model. Density functional theory calculations predict that this inductive effect occurs even in the absence of changes to the host framework geometry due to Ge -> Sn substitution. These results provide direct evidence in support of a measurable solid-electrolyte inductive effect and demonstrate its application as a practical strategy for tuning ionic conductivities in superionic lithium-ion conductors.

Harvard Citation style: Culver, S., Squires, A., Minafra, N., Armstrong, C., Krauskopf, T., Bocher, F., et al. (2020) Evidence for a Solid-Electrolyte Inductive Effect in the Superionic Conductor Li₁₀Ge_1-xSn_xP₂S₁₂, Journal of the American Chemical Society, 142(50), pp. 21210-21219. https://doi.org/10.1021/jacs.0c10735

APA Citation style: Culver, S., Squires, A., Minafra, N., Armstrong, C., Krauskopf, T., Bocher, F., Li, C., Morgan, B., & Zeier, W. (2020). Evidence for a Solid-Electrolyte Inductive Effect in the Superionic Conductor Li₁₀Ge_1-xSn_xP₂S₁₂. Journal of the American Chemical Society. 142(50), 21210-21219. https://doi.org/10.1021/jacs.0c10735