Biological ion channel inspired interfacial protection layer for high-performance zinc-ion batteries

The inherent safety, high theoretical specific capacity and low raw material cost of aqueous batteries make them potential candidates in large-scale energy storage. However, uncontrolled dendrite growth, parasitic reactions and sluggish mass transfer on the anode-electrolyte interface are the main challenges restricting the application prospect of aqueous zinc-ion batteries. In general, eukaryotic cells utilize specific ion channels to achieve ion migration with the merits of low energy consumption and rapid speed. Herein, migrating the concept of ion channels to aqueous batteries, a crown species encapsulated zeolitic imidazolate framework (ZIF) interfacial layer (denoted as ZIF@Crown) was ex situ decorated onto the Zn anode. Similar to biological ion channels, the ZIF@Crown layer can homogenize the distribution of Zn²⁺ on the anode, accelerate the desolvation of hydrated Zn²⁺ and reduce the energy barrier for Zn²⁺ deposition, which were verified by theoretical calculations and experimental characterizations. Benefiting from these efficacious modulation mechanisms, the Zn@ZIF@Crown symmetrical cell could achieve a long calendar life of over 1900 h and the Zn@ZIF@Crown||Cu also sustained 600 cycles with a high Coulombic efficiency (97%). Furthermore, the full cells containing ZIF@Crown layer exhibit desirable electrochemical performance. This work provides an innovative avenue toward the optimization of aqueous batteries via bionic interfacial engineering.

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