Unique ion rectifier intermediate enabled by ultrathin vermiculite sheets for high-performance Zn metal anodes

Metallic Zn represents as a primary choice in fabricating various aqueous Zn-ion batteries (ZIBs), however challenging issues including dendrite growth and parasitic reactions at the anode/electrolyte interface, considerably hamper its practical implementation in large-scale energy storage. Herein, we report a low-cost multifunctional ion rectifier (IRT) as an artificial intermediate to reform Zn anode, which can practically eliminate the above issues. The hydrophobic shell (polyvinylidene difluoride) can suppress Zn interfacial corrosion with an inhibition efficiency of 94.8% by repelling water molecules from the bulk electrolyte. Additionally, negatively-charged ion channels inside the zincophilic core (ultrathin vermiculite sheets) induce de-solvating redistribution effect on Zn²⁺ ions flux, enabling a high ions transference number (0.79) for dendrite-free Zn deposition. This leads to exceptional Zn/Zn²⁺ reversibility in metallic Zn with IRT stabilization. The remarkable Coulombic efficiency (99.8%, 2000 cycles) for asymmetrical batteries, and a long lifespan (1600 h) with ultrahigh cumulative capacity of 2400 mAh cm^-2 for symmetrical batteries, are successfully achieved. More encouragingly, the Zn//NH₄V₄O₁₀ pouch cell retains 94.3% of its original capacity after 150 cycles at 1 A g^-1. We believe that this low-cost and high-efficiency tactic could pave a promising path for anode surface modification.