Two-dimensional silicether as an excellent anode material for magnesium-ion battery with high capacity and fast diffusion ability

Exploring the excellent anode materials for metal-ion batteries is a hot spot in the energy storage field. Based on first-principles calculations, we propose two-dimensional (2D) silicether monolayer to be an outstanding anode for magnesium-ion batteries (MIBs). The relatively large adsorption energy (1.00 eV) for single Mg atom indicates good structural stability. Silicether could undergo the transition from semiconductor to metal even at a low Mg concentration (0.0625). Furthermore, silicether exhibits the low diffusion barrier (0.21 eV), the maximum storage capacity of 744 mAh g −1 , and a suitable open-circuit voltage (0.69–0.84 eV). A slight deformation and volume changes during full intercalation of Mg reveal a favorable cyclability. The above results suggest that silicether could be a promising candidate for MIBs. Graphical abstract Silicether as a new anode material for MIBs: fast ion mobility, high storage capacity,and appropriate OCV.