Stabilizing magnesium interfaces in aqueous magnesium-ion batteries via confined desolvation in MOF-801 sub-nanochannels.

Water-induced corrosion and passivation severely limit the practical application of aqueous magnesium metal batteries. Herein, we develop a sub-nanometre-channelled zirconium-based metal-organic framework, MOF-801, coating for stabilising Mg metal anodes. Acting as a molecular sieve, the MOF-801 layer promotes Mg2+ desolvation, suppresses interfacial parasitic water activity, mitigates water-mediated passivation reactions and preserves efficient ion transport. This nanoconfined interfacial microenvironment effectively alleviates continuous Mg corrosion, affording a low corrosion current of 0.9203 mA. The protected Mg anode consequently delivers stable Mg plating/stripping in symmetric cells and enhanced cycling durability in full cells. This study highlights sub-nanometre confinement as a promising route for regulating desolvation chemistry for durable aqueous Mg metal batteries.