Anti-dendrite separator interlayer enabling staged zinc deposition for enhanced cycling stability of aqueous zinc batteries

Abstract

Aqueous zinc ion batteries exhibit great prospects due to their low cost and high safety, while their lifespan is limited by severe dendritic growth problems. Herein, we develop an anti-dendrite hot-pressing separator interlayer through a mass-producible hot-pressing strategy, by spreading metal-organic framework (MOF) precursor on nonwoven matrix followed by a simple hot-pressing process. The in situ modification of MOF crystals on fiber surface processes abundant nitrogenous functional groups and high specific surface area (190.8 m² g⁻¹) with a strong attraction to Zn²⁺. These features contribute to a staged deposition behavior to promote uniform nucleation at high concentrations and two-dimensional grain growth at low concentrations. Consequently, Zn | |Zn symmetrical cells with hot-pressing separator interlayer demonstrate cycle lives of 3000 hours at 2 mA cm⁻², 2 mAh cm⁻². Moreover, Zn | |I₂ pouch batteries with hot-pressing separator interlayer realizes 840 cycles lifespan with a capacity retention of 90.9% and a final discharge capacity of 110.6 mAh at 25 °C.