AUTHOR=Dillenz Manuel , Sotoudeh Mohsen , Euchner Holger , Groß Axel 

TITLE=Screening of Charge Carrier Migration in the MgSc2Se4 Spinel Structure

JOURNAL=Frontiers in Energy Research

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2020.584654

DOI=10.3389/fenrg.2020.584654

ISSN=2296-598X

ABSTRACT=<p>Periodic density functional theory calculations have been performed to study the migration of various charge carriers in spinel‐type MgSc<sub>2</sub>Se<sub>4</sub>. This compound exhibits low barriers for Mg ion diffusion, making it a potential candidate for solid electrolytes in Mg-ion batteries. In order to elucidate the decisive factors for the ion mobility in spinel-type phases, the diffusion barriers of other mono- and multivalent ions (Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>, Cs<sup>+</sup>, Zn<sup>2+</sup>, Ca<sup>2+</sup>, and Al<sup>3+</sup>) in the MgSc<sub>2</sub>Se<sub>4</sub> framework have been determined as well. This allows for disentangling structural and chemical factors, showing that the ion mobility is not solely governed by size and charge of the diffusing ions. Finally, our results suggest that charge redistribution and rehybridization caused by the migration of the multivalent ions increase the resulting migration barriers.</p>