Superior plating/stripping performance through constructing an artificial interphase layer on metallic Mg anode

Rechargeable magnesium batteries (RMBs) have attracted tremendous attention in energy storage ap-plications in term of high abundance, high specific capacity and remarkable safety of metallic magne-sium (Mg) anode. However, a serious passivation of Mg anode in the conventional electrolytes leads to extremely poor plating/stripping performance, further hindering its applications. Herein, we propose a convenient method to construct an artificial interphase layer on Mg anode by substitution and alloy-ing reactions between SbCl3 and Mg. This Sb-based artificial interphase layer containing mainly MgCl2 and Mg3Sb2 endows the significantly improved interfacial kinetics and electrochemical performance of Mg anode. The overpotential of Mg plating/stripping in conventional Mg(TFSI)2/DME electrolytes is vastly reduced from over 2 V to 0.25-0.3 V. Combining experiments and calculations, we demonstrate that un-der the uniform distribution of MgCl2 and Mg3Sb2, an electric field with a favorable potential gradient is formed on the anode surface, which enables swift Mg2 + migration. Meanwhile, this layer can inhibit the decomposition of electrolytes to protect anode. This work provides an in-depth exploration of the artificial solid-electrolyte interface (SEI) construction, and a more achievable and safe path to realize the application of metallic Mg anode in RMBs.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Researchers propose a method to construct an artificial interphase layer on Mg anode by substitution and alloying reactions between SbCl3 and Mg, significantly improving the interfacial kinetics and electrochemical performance of Mg anode. This layer can reduce the overpotential of Mg plating/stripping and inhibit the decomposition of electrolytes to protect the anode. This work provides a more achievable and safe path to realize the application of metallic Mg anode in rechargeable magnesium batteries.