Constructing a Dual Interfacial Layer of Zinc Phytate and Halloysite Nanotubes with Enhanced Ion Sieving and Desolvation for an Ultrastable Zinc Metal Anode

Aqueous zinc-ion batteries (AZIBs) have garnered increasing attention due to their high safety and environmental friendliness. However, uncontrolled dendrite growth and severe side reactions on the Zn metal anode result in poor reversibility and cycling stability, hindering the practical application of AZIBs. Herein, we design and construct a dual interfacial layer by uniformly casting halloysite nanotubes (HNTs) with carboxymethyl cellulose (CMC) as a binder onto an amorphous zinc phytate (ZP) layer, which is formed via an in situ etching reaction between phytic acid and Zn metal. The ZP layer promotes the desolvation of Zn 2+ ions through strong coordination with phosphate groups, while the interfacial layer composed of HNTs and CMC provides an ion sieving effect, high mechanical robustness, and excellent interfacial adhesion. The synergistic effect of this dual-layer structure, denoted as ZPHC, effectively suppresses dendrite formation and side reactions. Consequently, the ZPHC@Zn symmetric cell achieves exceptional cycling stability over 3000 h at 1 mA cm –2 and 1 mAh cm –2 with a low overpotential of 46.4 mV. When coupled with a V 2 O 5 cathode, the ZPHC@Zn||V 2 O 5 full cell exhibits remarkable cycling performance, retaining 75.1% of its capacity after 1000 cycles at 5 A g –1 . This work presents a promising multifunctional dual interfacial layer strategy for ultrastable Zn metal anodes in high-performance AZIBs.