No abstract

Mg-ion batteries have the potential to replace the currently commercial Li-ion batteries due to its eco-friendliness and cost effective. However, because of the strong polarization of Mg-ions, conventional electrode materials are difficult to capture Mg-ions. In order to find an excellent anode material for Mg-ion batteries, we used the density functional theory to evaluate the applicability of T-type Mo2B monolayer and H-type Mo2B monolayer as electrode materials for Mg-ion batteries. The simulation results show that the adsorption energies of T-type Mo2B monolayer and H-type Mo2B monolayer for Mg atom are -1.08 eV and -0.78 eV (-2.16 eV and -2.14 eV with solvent effect), respectively, which are sufficient to ensure the stability of the procession of the magnesization. In addition, the ultra-low diffusion barriers (0.057 eV/0.110 eV) of Mg atom on their surfaces show a good charge and discharge rate. The theoretical specific capacity (529 mA h g-1) and the theoretical voltages (0.65 V/0.40 V) indicate that T-type Mo2B monolayer and H-type Mo2B monolayer are promising anode materials for Mg-ion batteries.