Sustainable Release of Zincophilic Metal Ions from Separator Proactively Drives Interfacial Stabilization for Durable Zinc Anode

One of the important challenges in advancing aqueous zinc-ion batteries is the separator, which is crucial for promoting stable electrode-electrolyte interface and energy density of the battery. Herein, this study introduces a metal ion-activated air-laid paper (ALP Act) as an alternative for traditional glass fiber separators with big thickness and weight. Notably, the sustainable release of metal ions facilitates in situ interface engineering, thus creating a surface layer with high zinc affinity to promote the uniform migration and deposition of zinc ions. By continuously adjusting the electrode-electrolyte interface, the behaviors of dendrite growth and side reactions are effectively suppressed. Consequently, the ALP Act with continuous metal-ion release function enables the zinc anode to attain a 21-fold increase in running life beyond 3700 h compared with the conventional glass fiber separator at 1 mA cm⁻² and l mAh cm⁻². The Zn||Cu battery also achieves a remarkable Coulombic efficiency of 99.18% for 2000 h (1 mA cm⁻²/1 mAh cm⁻²). The assembled Zn||NVO battery exhibits a lifespan of 3000 cycles for the charge and discharge cycles at 3 A g⁻¹. This research offers a new avenue for the separator to achieve low-cost, long-lasting, and energy-dense aqueous zinc batteries.