Study On Interface Regulation Of Magnesium Metal Anodes In Magnesium Secondary Battery

Due to the shortcomings of low energy density and poor safety,traditional commercial lithium-ion batteries have gradually failed to meet the increasing social demands.As one of the most potential alternatives,rechargeable Mg metal batteries（RMBs）have received extensive attention in virtue of high theoretical volumetric capacity,abundance in earth’s crust,low redox potential and without dendrites during cyclying.However,there are still some challenges that hinder the commercial applications of RMBs.One of the pivotal obstacles is the lack of an ideal electrolyte that can effectively transfer Mg²⁺.Different from the solid electrolyte interface（SEI）transporting Li⁺in Li batteries,a passivation layer hindering Mg²⁺conduct would be formed induced by the decomposition of electrolyte components or parasitic reactions between electrolytes and anodes.In order to adjust the interface between the magnesium metal anodes and the electrolyte effectively,herein,through adding Sb Cl₃,Si Cl₄,GeCl₄ in Mg（TFSI）₂electrolyte,the artificial protection layer was established on the surface of Mg metal anodes.The protection layer not only blocked the generation of the passivation layer,but also ensured the rapid transmission of magnesium ions.Subsequently,GeCl₄ was used as a representative additive to analyze the composition and structure of the Ge-based protection layer.More stringent test were carried out,which verified that there will be a self-repair process in the battery vivo,thereby ensuring the Ge-based artificial protection stability.Finally it successfully applied to the Ti S₂ and Ti₃C₂ cathode paired with full cells.