Interfacial Engineering of Magnesiophilic Coordination Layer Stabilizes Mg Metal Anode

Angew Chem Int Ed Engl. 2023 Jun 19;62(25):e202302617. doi: 10.1002/anie.202302617. Epub 2023 May 10.

Abstract

Rechargeable magnesium batteries (RMBs) are seriously plagued by the direct exposure of the Mg anode to the electrolyte components, leading to spontaneous and electrochemical side reactions and interfacial passivation. Herein, a benign coordination layer is constructed at the Mg/electrolyte interface where aniline with a strong magnesiophilic amine group and high stability to Mg is chosen as representative, which has higher adsorption energy than DME (1,2-dimethoxyethane) and trace water. This Mg coordination environment mitigates side reactions, forming a non-passivating interface consisting of aniline and much fewer by-products after several cycles. Therefore, the Mg symmetrical cell operates with a low overpotential and uniform Mg0 deposition. This interfacial coordination can also be adopted for Mg anode protection in various electrolyte cases of Mg(TFSI)2 electrolyte systems.

Keywords: Magnesiophilic Coordination Layer; Magnesium Metal Batteries; Passivation Layer; Side Reactions.

MeSH terms

  • Adsorption
  • Aniline Compounds*
  • Electrodes
  • Magnesium*

Substances

  • Magnesium
  • aniline
  • Aniline Compounds