(a) Rock-salt, (b) zinc-blende, and (c) spinel structure. The spinel lattice is an ordered mixture of the zinc-blende and rock-salt structure. The A species (yellow) of AB 2 X 4 occupy the tetrahedral sites, while the B species (blue) only occupy octahedral sites. The red spheres denote the oxide and chalcogenide anions such as O 2− , S 2− , and Se 2− .

(a) Rock-salt, (b) zinc-blende, and (c) spinel structure. The spinel lattice is an ordered mixture of the zinc-blende and rock-salt structure. The A species (yellow) of AB 2 X 4 occupy the tetrahedral sites, while the B species (blue) only occupy octahedral sites. The red spheres denote the oxide and chalcogenide anions such as O 2− , S 2− , and Se 2− .

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In the area of sustainable energy storage, batteries based on multivalent ions such as magnesium have been attracting considerable attention due to their potential for high energy densities. Furthermore, they are typically also more abundant than, e.g., lithium. However, as a challenge their low ion mobility in electrode materials remains. This stu...

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Context 1
... the complex transition-metal (B) oxides and chalcogenides, spinel structure with the composition Mg 2+ B 3+ 2 X 2− 4 correspond to the most promising Mg-ion conductors. 28,45,46 The spinel structure, illustrated in Fig. 1, consists of a face-centered cubic lattice of X anions (X = O, S, Se) with two kinds of interstices between the sites of the fcc lattice: tetrahedral interstices MgX 4 and octahedral interstices BX 6 . The BX 6 octahedra form a network of edgesharing chains while the Mg ions are located in the tetrahedrally vacant spaces of X ions, ...
Context 2
... general, our results and the analysis based on electronic and geometric factors provide a conceptual framework to understand fast ion conductivity in spinel electrode materials that will also be beneficial for the understanding and improvement of ion mobility in other materials classes. Figure 1 (a) Rock-salt, (b) zinc-blende, and (c) spinel structure. The spinel lattice is an ordered mixture of the zincblende and rock-salt structure. ...

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... 29 However, we could recently show that the stability of ions in chalcogenide spinels can only be understood if deviations from a purely ionic interaction are taken into account. 48 It is essential to realize that the considered binary materials span the whole range of interaction characteristics between metallic and ionic bonding. Such bonding characteristics can in fact been classified in so-called Van Arkel-Ketelaar triangles 49 in which compounds are placed according to the mean electronegativity χ mean (x-axis) and the electronegativity difference ∆χ (y-axis) of the constituting elements. ...
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Ion mobility is a critical performance parameter in electrochemical energy storage and conversion, but also in other electrochemical devices. Based on first-principles electronic structure calculations, we have derived a descriptor for the ion mobility in battery electrodes and solid electrolytes. This descriptor is entirely composed of observables that are easily accessible: ionic radii, oxidation states and the Pauling electronegativities of the involved species. Within a particular class of materials, the migration barriers are connected to this descriptor through linear scaling relations upon the variation of either the cation chemistry of the charge carriers or the anion chemistry of the host lattice. The validity of these scaling relations indicates that a purely ionic view falls short of capturing all factors influencing ion mobility in solids.The identification of these scaling relations has the potential to significantly accelerate the discovery of materials with desired mobility properties.