Atomic-layer-deposited hydrophobic-zincophilic Pd/g-C₃N₄ coating for ultra-stable aqueous Zn batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have emerged as promising candidates for large-scale energy storage systems in the post-lithium era, owing to their inherent safety and cost-effectiveness. However, their practical implementation faces significant challenges, including chemical corrosion, uncontrolled dendrite formation, and hydrogen evolution reactions (HER). To address these limitations, an innovative “hydrophobic-zincophilic” Pd/g-C₃N₄ composite coating was developed for Zn anodes by atomic-layer-deposition (ALD). The g-C₃N₄ matrix serves as an ion flux regulator, while uniformly dispersed Pd nanoparticles function as zincophilic nucleation sites, enabling homogeneous Zn deposition. In situ optical characterization demonstrates the coating’s dual functionality: the hydrophobic component effectively minimizes water contact, while the zincophilic phase guides ordered Zn plating, jointly suppressing parasitic reactions. The modified Pd/g-C₃N₄@Zn anode achieves exceptional cycling stability (> 2500 h) and maintains a remarkable Coulombic efficiency of 99.56% over 5000 cycles at 2 A/g, representing a significant advancement in AZIB anode engineering. This work provides a generalizable interfacial design strategy for developing high-performance AZIB systems.

Graphical abstract

Keywords

Zn anode / g-C₃N₄ / atomic layer deposition / hydrophobic / zincophilic / In-situ optical observation

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