First-principles calculations of bulk XTe₂ (X = Mo, W) as anode materials for Ca ion battery

Transition metal chalcogenides are excellent anode materials for calcium ion batteries (CIBs). In this study, the structural stability, electronic structure, and diffusion barrier of bulk XTe₂ (X = Mo, W) were studied by first-principles calculations within the framework of density functional theory. The density of states analysis shows the metal behavior of XTe₂ (X = Mo, W) during calcification. The voltage ranges of Ca_yMoTe₂ and Ca_yWTe₂ are 1.53–0.45 V and 1.48–0.41 V (y = 0–5), respectively. The diffusion barrier of Ca⁺ through XTe₂ indicates that the compressive strain promotes the diffusion of calcium through XTe₂. XTe₂ is considered to be a promising electrode material for CIBs.

In this paper, the transition metal chalcogenides model is constructed by Material Studio 8.0, and the first-principles calculation is carried out by CASTEP module.