Hierarchically Structured Artificial SEI with Interlayer Electronic Coupling for High‐Performance Aqueous Zinc Batteries

Why It Matters

By stabilizing the zinc anode and suppressing dendrites, the artificial SEI unlocks longer cycle life and higher power for low‑cost, safe aqueous batteries, accelerating their adoption in grid‑scale storage.

Key Takeaways

• Artificial SEI achieves 20.26 mS cm⁻¹ ionic conductivity.
• Zn²⁺ transference number reaches 0.89, reducing parasitic reactions.
• Zn//Zn cells stable over 4,000 hours of cycling.
• Zn//MnO₂ full cell retains 77% capacity after 700 cycles.
• Interlayer electron coupling repels SO₄²⁻, suppresses dendrite growth.

Pulse Analysis

Aqueous zinc‑ion batteries have attracted attention for large‑scale energy storage because they combine intrinsic safety with inexpensive raw materials. Yet, uncontrolled zinc dendrite growth, electrolyte corrosion, and unstable solid‑electrolyte interphases have limited their practical deployment. Conventional SEI layers formed in situ often lack sufficient ionic conductivity and fail to manage the electric field at the electrode surface, leading to rapid capacity fade and safety concerns. Addressing these shortcomings requires a deliberate interfacial architecture that can both conduct ions efficiently and modulate electronic interactions.

The ZnO@MX‑DE artificial SEI leverages a multi‑step synthesis that starts with ZIF‑8 templating, followed by MXene coating, ZnO conversion, and integration of dickite nanosheets. This creates a petalosphere heterostructure where electrons migrate from Zn/Ti centers toward oxygen‑rich dickite, establishing an interlayer electron coupling effect. The resulting SEI exhibits an ultrahigh ionic conductivity of 20.26 mS cm⁻¹ and a Zn²⁺ transference number of 0.89, meaning that zinc ions dominate charge transport while anions are effectively excluded. Such electronic reconstruction not only accelerates Zn²⁺ adsorption but also repels SO₄²⁻, curbing parasitic side reactions and thermodynamically discouraging dendrite nucleation.

The performance gains translate into tangible commercial advantages. Symmetric Zn//Zn cells demonstrated uninterrupted cycling for more than 4,000 hours, and full cells paired with MnO₂ cathodes maintained 77% of their initial capacity after 700 high‑rate cycles, with endurance up to 40,000 cycles at extreme current densities. These metrics suggest that the engineered SEI can support the high power and long‑duration operation demanded by renewable‑energy integration and grid‑balancing applications. As the industry seeks cost‑effective alternatives to lithium‑based systems, such interfacial engineering strategies could become a cornerstone for next‑generation, safe, and durable aqueous battery technologies.