First-Principles Study of Monolayer <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi>p</mml:mi><mml:mi>e</mml:mi><mml:mi>n</mml:mi><mml:mi>t</mml:mi><mml:mi>a</mml:mi></mml:math>-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msub><mml:mrow><mml:mi>Co</mml:mi><mml:mi mathvariant="normal">S</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:math> as a Promising Anode Material for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi>Li</mml:mi></mml:math>/<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi>Na</mml:mi></mml:math>-ion Batteries
M. Debbichi, Abdulrahman Mallah, Mohamed Houcine Dhaou, Sébastien Lebègue∥
Abstract
Using first-principles calculations, we investigate the properties of the ${\mathrm{Co}\mathrm{S}}_{2}$ monolayer pentagonal structure as a possible anode material for $\mathrm{Li}$- and $\mathrm{Na}$-ion batteries. The geometrical optimization reveals that the metal atom prefers to be adsorbed on the hollow site, and that the diffusion barrier of $\mathrm{Li}$ and $\mathrm{Na}$ can be as low as 0.22 eV, which would allow a relatively fast diffusion on the surface. Moreover, our calculations demonstrate that the ${\mathrm{Co}\mathrm{S}}_{2}$ monolayer has a theoretical specific capacity of 653.31 and $326.77\phantom{\rule{0.2em}{0ex}}\mathrm{mAh}\phantom{\rule{0.2em}{0ex}}{\mathrm{g}}^{\ensuremath{-}1}$ for $\mathrm{Li}$ and $\mathrm{Na}$, respectively, which in the case of $\mathrm{Li}$ is larger than the capacity of other two-dimensional materials used as an anode material. Overall, the ${\mathrm{Co}\mathrm{S}}_{2}$ monolayer in this structure shows excellent electrochemical properties, making it a promising candidate for use as the anode material in metal-ion batteries.