Atomic-scale studies of garnet-type Mg3Fe2Si3O12: Defect chemistry, diffusion and dopant properties
File(s)
Published version
Author(s)
Kuganathan, Navaratnarajah
Chroneos, Alexander
Type
Journal Article
Abstract
Materials with low cost, environmentally benign, high structural stability and high Mg content are of considerable interest for the construction of rechargeable Mg-ion batteries. In the present study, atomistic simulations are used to provide insights into defect and diffusion properties of garnet type Mg3Fe2Si3O12. Calculations reveal that the Mg-Fe anti-site defect cluster (0.44 eV/defect) is the lowest energy intrinsic defect process. Three dimensional Mg-ion migration pathway with the activation energy of 2.19 eV suggests that Mg-ion diffusion in this material is slow. Favourable isovalent dopants are found to be Mn2+, Ga3+ and Ge4+ on the Mg, Fe and Si sites respectively. While the formation of Mg interstitials required for the capacity is facilitated by Al doping on the Si site, Mg vacancies needed for the vacancy assisted Mg-ion diffusion are enhanced by Ge doping on the Fe site. The electronic structures of favourable dopants are calculated and discussed using density functional theory.
Date Issued
2020-07
Date Acceptance
2020-07-01
Citation
Journal of power sources advances, 2020, 3, pp.1-7
ISSN
2666-2485
Publisher
Elsevier
Start Page
1
End Page
7
Journal / Book Title
Journal of power sources advances
Volume
3
Copyright Statement
© 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.sciencedirect.com/science/article/pii/S2666248520300160?via%3Dihub
Subjects
Defects
Diffusion
Mg3Fe2Si3O12
Dopants
Atomistic simulation
LITHIUM DIFFUSION
CATHODE MATERIALS
SELF-DIFFUSION
ION DIFFUSION
METAL-OXIDES
BATTERY
MAGNESIUM
VOLTAGE
INTERCALATION
MGFESIO4
Publication Status
Published
Date Publish Online
2020-07-30