Synergistic Ion Regulation and Interface Stabilization Enabled by a PVA/ZIF-8 Hybrid Layer for Dendrite-Free Zinc Anodes

Aqueous zinc-ion batteries (AZIBs) offer considerable potential for sustainable energy storage; however, dendritic growth and interfacial parasitic reactions severely hinder the reversibility of zinc anodes. Herein, we report a multifunctional hybrid protective interphase (PVA/ZIF-8@Zn) constructed by combining poly(vinyl alcohol) (PVA) with zeolitic imidazolate framework-8 (ZIF-8). PVA molecules regulate the Zn2+ solvation structure through hydroxyl coordination, while ZIF-8 provides zinc affinity via its nitrogen sites, guiding uniform Zn2+ deposition and suppressing dendrite growth. Moreover, the synergistic combination of PVA’s intrinsic flexibility and ZIF-8’s structural rigidity suppresses parasitic side reactions and effectively accommodates volumetric fluctuations of the zinc anode during cycling. Consequently, the PVA/ZIF-8@Zn anode exhibits exceptional stability, achieving over 2400 h of reversible cycling in symmetric cells at 1 mA cm–2 and 1 mAh cm–2. Furthermore, the assembled full cells deliver a discharge capacity of 79 mAh g–1 after 2000 cycles at 1 A g–1, corresponding to a capacity retention of 75%. This work provides a feasible design strategy for constructing “rigidity-flexibility synergistic” interfacial layers for high-performance AZIBs.