Hierarchically Porous Diatomite Coating as an Ion Redistributor for Dendrite-Free Zinc Anodes

The relentless challenges of uncontrolled zinc dendrite growth and severe interfacial side reactions pose a significant threat to the operation and reliability of aqueous zinc-ion batteries (AZIBs). To counter these challenges, this work introduces a novel multifunctional interfacial layer engineered from diatomite (DIA) on the zinc anode. The hierarchically ordered porous architecture and enhanced surface area of modified diatomite (M-DIA) serve as an ion transport channel to homogenize the Zn²⁺ ion flux, further suppressing dendrite formation. Meanwhile, the hydrophobic layer acts as a robust physical barrier, effectively shielding the zinc surface from the aqueous electrolyte. This concerted mechanism yields a dendrite-free morphology and exceptional corrosion resistance. Consequently, the M-DIA@Zn anode enables remarkably stable symmetric cell cycling stability over 1200 h at 2 mA cm^-2 and 1500 h at 5 mA cm^-2, respectively, and achieves an average Coulombic efficiency of 98.6% in asymmetric cells. When paired with a MnO₂ cathode, the full cell exhibits superior capacity retention (260 mAh g^-1 after 100 cycles) and outstanding rate performance. This work underscores the potential of natural diatomite as a multifunctional interface for stabilizing metal anodes, offering a promising pathway toward high-performance and durable zinc-based energy storage.