Theoretical study on the effect of shear deformation on MoTe as cathode material for calcium ion batteries.

Context: In this study, the electronic structure and diffusion barrier of Ca adsorbed MoTe system under different degrees of shear deformation were calculated based on the first-principles method. The results show that both the pure MoTe system and Ca-adsorbed MoTe system are affected by shear deformation. The pure MoTe undergoes a transition from direct to indirect band gap under shear deformation. The adsorption of Ca makes MoTe changes from semiconductor to quasi-metal. The results of the density of states show that Ca insertion makes the conduction band part of the adsorption system significantly enhanced. The diffusion barrier of Ca through MoTe indicates that the shear deformation promotes the diffusion of Ca on the surface of MoTe. Shear deformation can effectively modulate the electronic properties of the MoTe system, which provides a theoretical basis for the application of MoTe materials in the field of ion batteries.

Methods: In this study, Materials Studio 8.0 software was used to construct the MoTe model and Ca adsorbed MoTe model, and the CASTEP module was used for first-principles calculation.