Sulfur‐ and Selenium‐Containing Compounds Potentially Exhibiting Al Ion Conductivity

Abstract

We have created a set of crystalline model structures exhibiting straight lines of Al3+ connected to chalcogenides (O2−, S2−, and Se2−) connected to metal cations of varying valence (Sr2+, Y3+, Zr4+, Nb5+, and Mo6+). They were relaxed with density functional theory computations and analysed by Bader partitioning. As Al3+ ions are supposed to strongly interact with their atomic environment, we studied the electron density topology induced by higher‐valent cations in the extended chemical neighbourhood of Al. In fact, we found a general decrease of ionic charges and an increasing displacement of the chalcogenides towards higher‐valent ions for the heavier chalcogens. Therefore, we comprehensively screened S‐ and Se‐containing compounds for candidates theoretically exhibiting low migration barriers for Al3+ ions by using Voronoi–Dirichlet partitioning and bond valence site energy calculations. The basis for this search is the Inorganic Crystal Structure Database. Indeed, we could extract six promising candidates with low Al3+ migration barriers. which are even lower than the barriers for any other element inside of these materials. This will encourage efforts towards preparing suitable Al3+ conductors.

A novel class of multivalent ionic conductors with the La3CuSiS7 structure type: results of stepwise ICSD screening

“…Most of these structures are known as optical band gap semiconductors 23,27,28 and little information on ionic conductivity was found. Thus, Gulay et al 29,30 supposed disordered silver atoms contributing to the ionic conductivity in Ag x Ln 3 TSe 7 , and Meutzner et al 14 mentioned Al 0.44 La 3 Si 0.93 S 7 as a possible Al-conductor.…”

“…1). [12][13][14] Moreover, the chalcogen-containing conductors usually have lower synthesis temperatures and mechanical stiffness. 15,16 In Fig.…”

“…Sotoudeh et al 19 investigated Mg 2+ ion mobility in spinel-like compounds and found easier diffusion in selenides compared with sulfides. Meutzner et al 14 studied the electron density in the model Al–MX (M = Sr 2+ , Y 3+ , Zr 4+ , Nb 5+ or Mo; X = O 2− , S 2− , Se 2− ) structures and found an overall decrease in ionic charges and an increased displacement of the heavier chalcogenide ions toward the higher-valent ions. Other theoretical and experimental studies have also confirmed this general trend.…”

Metalloid-doping in SMoSe Janus layers: first-principles study on efficient catalysts for the hydrogen evolution reaction

“…Transition metal dichalcogenide (TMD)-based two-dimensional (2D) materials have been strongly in focus recently due to their various structure-driven electronic and optical properties, suitable for a wide range of applications, such as in nanoelectronics, 1,2 spintronics, 3 gas sensing, 4,5 photocatalysis, 1,[6][7][8][9] electro-catalysis, [10][11][12][13][14][15] electrochemical energy storage, [16][17][18][19] and photonics. 20,21 The hexagonal phase is the most common stable phase of 2D materials.…”