The Intercalation Phase Diagram of Mg in V2O5 from First-Principles

Gautam, G. S.; Canepa, P.; Abdellahi, A.; Urban, A.; Malik, R.; Ceder, G.

doi:10.1021/acs.chemmater.5b00957

The Intercalation Phase Diagram of Mg in V₂O₅ from First-Principles

G. S. Gautam, P. Canepa, A. Abdellahi, A. Urban, R. Malik, and G. Ceder; Chem. Mater. 27, 3733–3742 (2015).

BibTeX

@article{Gautam2015intercalation,
  author  = {Gautam, G. S. and Canepa, P. and Abdellahi, A. and Urban, A. and Malik, R. and Ceder, G.},
  title   = {{The Intercalation Phase Diagram of Mg in V$_{2}$O$_{5}$ from First-Principles}},
  journal = {Chemistry of Materials},
  volume  = {27},
  pages   = {3733--3742},
  year    = {2015},
  doi     = {10.1021/acs.chemmater.5b00957}
}

Abstract

We have investigated Mg intercalation into orthorhombic V₂O₅, one of only three cathodes known to reversibly intercalate Mg ions. By calculating the ground-state Mg_xV₂O₅ configurations and by developing a cluster expansion for the configurational disorder in δ-V₂O₅, a full temperature–composition phase diagram is derived. Our calculations indicate an equilibrium phase-separating behavior between fully demagnesiated α-V₂O₅ and fully magnesiated δ-V₂O₅, but also motivate the existence of potentially metastable solid solution transformation paths in both phases. We find significantly better mobility for Mg in the δ polymorph, suggesting that better performance can be achieved by cycling Mg in the δ phase.