Inorganic interface engineering for stabilizing Zn metal anode

As lithium costs soar and safety incidents mount, aqueous zinc-ion batteries (AZMBs) promise a cheap, non-flammable alternative—yet zinc anodes still rot from within, sprouting dendrites that short-circuit cells in days while hydrogen bubbles swell the pack. Now, a multi-institute team led by Prof. Qingli Zou (Beijing University of Chemical Technology) and Prof. Hongjin Fan (Nanyang Technological University) has delivered a design manual in Nano-Micro Letters that turns commercial Zn foil into an ultra-stable anode through simple, low-cost inorganic coatings, pushing symmetric cells beyond 6500 h and pouch cells past 200 cycles at 10 mAh cm^-2.

Why Inorganic Interface Engineering Matters

· Dendrite Suppression: Dense Al₂O₃, ZnO or TiO₂ layers homogenize surface charge and provide zincophilic nucleation sites, forcing lateral (002)-textured growth instead of mossy filaments.

· Hydrogen Evolution Blockade: Phosphate, silicate or MXene barriers physically isolate water from the metal, cutting HER to <0.1 % per cycle and eliminating cell swelling.

· High Areal Capacity: Non-consumable, corrosion-resistant coatings tolerate >10 mAh cm^-2 and 50 mA cm^-2—meeting practical targets for grid storage and e-mobility.

Innovative Design & Features

· Material Palette: Metal oxides (TiO₂, ZrO₂, Nb₂O₅), nitrides (TiN, CrN), sulfides/selenides (ZnS, ZnSe), MXenes (Ti₃C₂Cl₂) and acid salts (Zn₃(PO₄)₂, sepiolite) are compared for ionic conductivity, adsorption energy and mechanical strength.

· Structure Engineering: Atomic-layer-deposited 10 nm Al₂O₃, micro-concave ZnO, hollow ZnSnO₃ cubes and 45 nm zinc-phosphate SEI each demonstrate specific pathways to guide Zn²⁺ flux and suppress side reactions.

· Scale-Up Compatibility: All coatings are deposited by spray, dip, ALD or simple chemical bath—compatible with roll-to-roll processing of commercial Zn foil.

Applications & Future Outlook

· Grid-Scale Storage: A 1 Ah Zn||V₂O₅ pouch cell with Zn-phosphate interface retains 80 % capacity after 200 cycles at 10 mAh cm^-2, projecting <$60 kWh^-1 system cost.

· Flexible Devices: 10 nm MXene-coated Zn anodes survive 1 500 bends in Zn-I₂ thread batteries, enabling wearable e-textiles.

· Next Steps: Team is integrating AI-guided lattice-matching models and in-line thickness monitoring to transfer the technology to 100 Ah modules by 2026.

This roadmap converts the zinc anode from a liability into a long-lived, high-energy asset, positioning AZMBs as the front-runner for safe, sustainable and low-cost energy storage.