Fast Zinc-ion Shuttle Channel with Built-in Ion-anchors Enables Reversible and Sustainable Zinc Metal Anodes

Aqueous zinc metal batteries (AZMBs) have been persistently constrained by dendrites and parasitic reactions arising from competitive reduction reactions between Zn²⁺ and water molecules at the electrode/electrolyte interface. In this study, we introduced an interfacial fast Zn²⁺ shuttle channel (Sph2400-DM) to address these issues. This ion shuttle channel is fabricated using sphalerite (Sph2400) raw ore as the matrix, with its inner walls embedded with zinc-ion anchor (DM) heterostructures. This structure synergistically integrates selective fast transport and interfacial Zn²⁺ flux regulation, enhancing the migration efficiency and homogenized concentration gradient distribution of Zn²⁺ at the electrode/electrolyte interface. Consequently, the system demonstrates highly reversible Zn²⁺ plating/stripping for over 3300 h and achieves a cycling life exceeding 600 h at 50% depth of discharge. Moreover, attributed to repelled water molecules and enhanced Zn²⁺ kinetics, the NH₄V₄O₁₀||Sph2400-DM@Zn full cell (cathode loading of 13.91 mg cm^-2) achieves stable cycling over 680 cycles with negligible capacity decay at 1 A g^-1. Surprisingly, the pouch cell with high cathode loading (8.81 mg cm^-2) and low N/P ratio (2.6) presents 83.8% capacity retention after 200 cycles at 0.8 A g^-1, further demonstrating the effectiveness of this strategy.