Bismuth/tin-based artificial interface for overcoming the anode passivation of rechargeable magnesium batteries

A bimetallic Bi/Sn artificial interface layer is constructed on an Mg anode via displacement reaction to address passivation challenges in ether-based electrolytes. Compared to the nucleation overpotential of Mg (-3.21 V), that of the fabricated BiSn@Mg is lower (0.098 V), and its deposition overpotential is below 0.21 V. The BiSn@Mg//BiSn@Mg cell can run stably for 4000 h with a good rate capability. The constructed artificial interface enhances Mg/electrolyte compatibility and reaction kinetics. This work advances reversible Mg plating/stripping in ether-based electrolytes.