Nucleophilic Interfacial Layer Enables Stable Zn Anodes for Aqueous Zn Batteries.

Abstract

Aqueous Zn batteries are emerging as promising energy storage devices. However, severe dendrite growth and side reactions of Zn anodes restrict their further development. Herein, we develop a nucleophilic interfacial layer (NIL) on Zn to achieve a highly stable Zn anode for rechargeable Zn batteries. The NIL in a composition of zinc acetate acetamide is homogeneous, compact, and Zn²⁺-conductive, rendering dendrite-free Zn deposition, which is observed by in situ optical microscopy. Benefiting from the advantages of NIL, the Zn||Zn symmetric cells show a low overpotential of 0.12 V at a high current density of 40 mA/cm², enhanced Coulombic efficiency up to 99.9%, and extended lifespan over 2600 cycles. The Zn||Ti asymmetric cells exhibit a high areal capacity of 5 mAh/cm². Moreover, the NIL functionalized Zn anode enables stable cycling of both anode-free Zn||Cl₂ cells and zinc-ion capacitors, providing opportunities for the development of high-performance energy storage devices.