Modulating the Reactivity of Amine-Based Electrolytes for Stable Rechargeable Magnesium Batteries

Abstract Despite their advantages complementary to lithium- and sodium-ion batteries, rechargeable magnesium batteries (RMBs) still suffer from multiple limitations that impede their commercialization. Amine-based electrolytes have recently emerged as promising options to overcome the long-standing challenge of sluggish Mg2+ ion transport at the magnesium metal interface; however, their uncontrolled chemical and electrochemical reactivity impairs cycling and calendar life. After screening a range of bidentate methoxyethylamine derivatives, we herein identify aminoacetaldehyde dimethyl acetal (ADMA)─functionalized with a methoxy substituent─as a single electrolyte solvent that achieves an optimal balance between interfacial ionic transport and (electro)chemical stability. These optimal properties are enabled by the concerted modulation of electron donicity and steric hindrance in ADMA. Co…