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Development of a Mg/O ReaxFF Potential to describe the Passivation Processes in Magnesium‐Ion Batteries

Fiesinger, Florian; Gaissmaier, Daniel 1; van den Borg, Matthias; Beßner, Julian; van Duin, Adri C. T.; Jacob, Timo 1
1 Helmholtz-Institut Ulm (HIU), Karlsruher Institut für Technologie (KIT)

Abstract:

One of the key challenges preventing the breakthrough of magnesium-ion batteries (MIB) is the formation of a passivating boundary layer at the Mg anode. To describe the initial steps of Mg anode degradation by O$_2$ impurities, a Mg/O ReaxFF (force field for reactive systems) parameter set was developed capable of accurately modeling the bulk, surface, adsorption, and diffusion properties of metallic Mg and the salt MgO. It is shown that O$_2$ immediately dissociates upon first contact with the Mg anode (modeled as Mg(0001), Mg(10$\bar1$0)A, and Mg(10$\bar1$1)), heating the surface to several 1000 K. The high temperature assists the further oxidation and forms a rock salt interphase intersected by several grain boundaries. Among the Mg surface terminations, Mg(10$\bar1$0)A is the most reactive, forming an MgO layer with a thickness of up to 25 Å. The trained force field can be used to model the ongoing reactions in Mg–air batteries but also to study the oxidation of magnesium metal in general.


Verlagsausgabe §
DOI: 10.5445/IR/1000155477
Veröffentlicht am 02.02.2023
Originalveröffentlichung
DOI: 10.1002/cssc.202201821
Scopus
Zitationen: 5
Web of Science
Zitationen: 4
Dimensions
Zitationen: 7
Cover der Publikation
Zugehörige Institution(en) am KIT Helmholtz-Institut Ulm (HIU)
Post Lithium Storage (POLiS)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 08.02.2023
Sprache Englisch
Identifikator ISSN: 1864-5631, 1864-564X
KITopen-ID: 1000155477
HGF-Programm 38.02.02 (POF IV, LK 01) Components and Cells
Erschienen in ChemSusChem
Verlag Wiley-VCH Verlag
Band 16
Heft 3
Seiten Art.-Nr.: e202201821
Vorab online veröffentlicht am 08.11.2022
Schlagwörter batteries, magnesium, multi-scale modeling, passivation, ReaxFF
Nachgewiesen in Scopus
Web of Science
Dimensions
Globale Ziele für nachhaltige Entwicklung Ziel 7 – Bezahlbare und saubere Energie
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