Novel phases of lithium-aluminum binaries from first-principles structural search

Rafael Sarmiento-Perez (1) , Tiago F. T. Cerqueira (1) , Irais Valencia-Jaime (1) , Maximilian Amsler (2) , Stefan Goedecker (2) , Aldo H. Romero (3) , Silvana Botti (1) , Miguel A. L. Marques (1)

1 ILM - Institut Lumière Matière [Villeurbanne]
2 Unibas - Université de Bâle = University of Basel = Basel Universität
3 West Virginia University [Morgantown]

Intermetallic Li–Al compounds are on the one hand key materials for light-weight engineering, and on the other hand, they have been proposed for high-capacity electrodes for Li batteries. We determine from first-principles the phase diagram of Li–Al binary crystals using the minima hopping structural prediction method. Beside reproducing the experimentally reported phases (LiAl, Li3Al2, Li9Al4, LiAl3, and Li2Al), we unveil a structural variety larger than expected by discovering six unreported binary phases likely to be thermodynamically stable. Finally, we discuss the behavior of the elastic constants and of the electric potential profile of all Li–Al stable compounds as a function of their stoichiometry.

Domaines: Chimie inorganique; Chimie théorique et/ou physique

Rafael Sarmiento-Perez, Tiago F. T. Cerqueira, Irais Valencia-Jaime, Maximilian Amsler, Stefan Goedecker, et al.. Novel phases of lithium-aluminum binaries from first-principles structural search. Journal of Chemical Physics, 2015, 142, pp.024710. ⟨10.1063/1.4905141⟩. ⟨hal-02305573⟩