Theoretical investigation of strain-engineered WSe2 monolayers as anode material for Li-ion batteries

Abstract It poses a great challenge to design anode materials with large capacity, excellent cyclic stability and high rate performance. In this paper, through first principle calculations, we computed electronic properties of monolayer WSe2 with and without strain effects. Our results show that the electronic band gap decreases with strain percent. At 0% tensile strain the value of the band gap is 1.4 eV while at 10% tensile strain the band gap decreases to 0.7 eV. Therefore, the strain effect enhances the electronic conductivity and leads to an increase in the charge carrier transport. In addition, our predictions show that the adsorption energy increases with the strain. Finally, we computed the diffusion barrier for the migration of Li on the surface of a strain engineered WSe2 monolayer. The lower barrier energy (0.24 eV) reveals that Li can easily overcome this barrier. Our results show that the strain-engineered WSe2 monolayers are promising anode material for Li-ion battery.