Hydrophobic Metal-Organic Framework-Based Ion-Conductive Interfaces Toward Stabilizing Zn Metal for High-Performance Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) have received numerous attention due to their high safety, low cost, and environmental friendliness. However, Zn metal suffers from uncontrollable dendritic Zn growth, H₂ generation and Zn corrosion, etc., which seriously reduce the lifetime of aqueous zinc-metal batteries. To overcome these challenges, an artificial hydrophobic metal-organic framework (MOF)-based ion-conductive protective coating is constructed to stabilize the Zn metal anode for high-performance AZIBs. The hydrophobic pores in zeolitic imidazolate framework (ZIF-8) provide channels for rapid Zn-ions migration, reduce the desolvation activation energy of Zn-ions, and facilitate Zn uniform deposition, inhibiting dendrite growth. Meanwhile, the outer layer polydimethylsiloxane (PDMS) around ZIF-8 prevents Zn metal from contacting water molecules, which suppresses H₂ generation, Zn corrosion, and by-products formation. Thus, the lifetime of PDMS@ZIF-8-modified Zn anode extends over 1100 h at the current density/areal capacity of 2 mA cm⁻²/1 mAh cm⁻², significantly longer than that of bare Zn (80 h). Meanwhile, the full cells paired with a VO₂ cathode exhibit excellent long-term cycling stability, maintaining 82.3% capacity retention after 870 cycles at 3A g⁻¹, which is much higher than that of bare Zn (61.3%). This facile strategy is applicable to other aqueous metallic batteries toward practical applications.