Engineering Core–Shell Interfaces with Hierarchical Mass Transport for Dendrite‑Free and Highly Reversible Zn Anodes

ABSTRACT

Aqueous zinc batteries are plagued by dendrite growth and parasitic reactions, calling for a rational interfacial design. Herein, we construct a core–shell ZIF‐8@SiO ₂ architecture on the Zn anode (ZFSI@Zn) via a self‐nucleation route. The hydrophilic SiO ₂ shell and anion‐affinitive ZIF‐8 core synergistically facilitate Zn ²⁺ desolvation and transport, enhancing the 3D diffusion contribution while effectively suppressing interfacial concentration polarization. Consequently, the ZFSI@Zn anode delivers an extended lifespan of 1800 h at 1 mA cm ⁻² /1 mAh cm ⁻² and maintains remarkable stability even at an ultrahigh current density of 50 mA cm ⁻² . Beyond anode protection, strong SO ₄ ²⁻ adsorption confers a negative surface charge that electrostatically repels I ₃ ⁻ , thereby eliminating the shuttle effect in Zn‐I ₂ batteries. This enables a maximum specific capacity of 202.3 mAh g ⁻¹ at 0.2 A g ⁻¹ and an outstanding capacity retention of 89.8% over 65 000 cycles at 5 A g ⁻¹ , corresponding to an ultralow capacity decay of merely 0.00015% per cycle. The superior performance is further validated under high cathode loadings and in pouch‑cell configurations. Overall, this work establishes core–shell interfacial engineering as a versatile platform for tackling the multiple challenges in zinc‑based energy storage.