Imidazole‐Amine Synergistic Coordination Reconstructs H‐Bonds and Interface Engineering for Mg Metal Batteries at 60°C

ABSTRACT Rechargeable magnesium batteries (RMBs) are greatly hindered by critical issues in ether and ether‐nitrogen co‐solvent electrolytes, such as Mg anode passivation, large overpotential, poor thermal stability, and flammability. Herein, we design a deep eutectic electrolyte (DEE, DMSA) consisting of dimethylimidazole (DMIm), Mg(TFSI) 2, and 2‐methoxyethylamine (MEA) in a molar ratio of 16:1:3. The dual role of the MEA additive synergistically involves the cleavage of the excessively strong DMIm–Mg 2 + solvation structure and the reconfiguration of the robust DMIm‐TFSI − hydrogen‐bonding network. Through imidazole‐amine coordination competition and a synergistic hydrogen‐bonding network, the solvation structure is reconstructed with a reduced Mg desolvation barrier. Meanwhile, the in situ MgF 2 ‐rich organic/inorganic bilayered SEI ensures the interfacial stability and cycling lifespan. In particular, the inorganic layer portion of MgF 2 ‐rich, effectively enhances the stability of the SEI layer at high temperatures. The optimal DEE features intrinsic flame retardancy, a broad operating temperature range (10–80°C), and an ultra‐low overpotential of 35 mV. Astoundingly, the Mg||Mg cell runs stably for 400 h at 80°C. Impressively, the Mg||Mo 6 S 8 cell realizes long cycling over 1000 cycles even at 5 C at 25°C and 150 cycles at 60°C. This work establishes a new solvation design principle that fundamentally resolves the long‐standing incompatibility between Mg and non‐aqueous eutectic electrolytes, unlocking high‐performance, high‐temperature RMBs.