Multifunctional Core-Shell Structured Interface Layer Regulate Zn Deposition Behavior and Anti-Polyiodide Ions...

Zinc-iodine (Zn-I₂) batteries have attracted extensive attention in energy storage domains on account of their rich natural reserves, higher voltage platforms, and non-ion in(de)intercalation mechanism. Yet their practical utilization is restricted by the Zn dendrites growth and side reactions, as well as serious polyiodides dissolution and shuttling. Herein, a core-shell structured InHCF@ZIF-8 (IHZ) was designed and synthesized via electrostatic self-assembly, serving as a multifunctional interface layer for Zn anodes. Driven by the dual coordination mechanism of InHCF and ZIF-8, IHZ exhibits excellent Zn affinity and a high hydrogen evolution overpotential, which not only induces uniform Zn deposition but also realizes the homogeneous distribution of local electric field and Zn²⁺ flux. Furthermore, the strong adsorption of IHZ on the Zn (002) plane directs the horizontal deposition of Zn, thus effectively suppressing dendrite nucleation and growth. Meanwhile, the self-discharge effect is mitigated via electrostatic repulsion toward I₃ ^-. As a result, symmetric cells employing the Zn@IHZ anode deliver an ultralong cycle life of 6490 h at 0.5 mA cm^-2 and 0.5 mAh cm^-2. The Zn@IHZ anode endows the Zn-I₂ battery with a remarkable capacity, excellent rate capability, and an ultralong lifespan over 14800 cycles.