Theoretical Study of Halogen Anion Batteries With Ultra-Thin InSe

Abstract

We systematically explored the adsorption, diffusion, thermodynamics stability, and electrochemical performance of halogen anions (F⁻, Cl⁻, Br⁻, I⁻) on monolayer InSe using first-principles calculations. F⁻, due to its strong electronegativity, has a destructive effect on the surface. The rank of the adsorption ability of other three anions is Cl⁻ > Br⁻ > I⁻ according to the value of adsorption energy, which is agreement with their electronegativity strength. It was found that the halogen anions exhibited excellent diffusion performance with low diffusion energy barriers. Cl⁻ can adsorb up to three layer showing an excellent theoretical capacity of 415 mA h g⁻¹, while Br⁻ and I⁻ cannot obtain a stable structure when the coverage exceeds 1 and (2/3) layer. In summary, this study evaluates a prospective electrode material and establishes a theoretical foundation for the development of novel rechargeable batteries.