Facilitated Zn2+ Transport and Preferential Zn (100) Deposition Enabled by Amorphous ZrOx-C Hybrid Thin Film for High-Performance Aqueous Zinc-Ion Batteries.

Abstract

Although aqueous zinc-ion batteries (AZIBs) are emerging as promising candidates for large-scale energy storage due to their intrinsic safety and cost-effectiveness, the practical deployment of metallic zinc (Zn) anodes is still plagued by uncontrolled dendrite growth, corrosion, and competing hydrogen evolution reaction (HER) at the Zn/electrolyte interface. Surface/interface engineering with organic-inorganic hybrid layers has recently proven effective in homogenizing Zn2+ flux and suppressing parasitic reactions. In parallel, ultrathin inorganic oxide coatings such as ZrO2 have been shown to enable dendrite-free cycling in aqueous media.​ In this study, an amorphous zirconium oxide-carbon (a-ZrOx-C) hybrid thin film is engineered on the Zn anode surface via ultraviolet-ozone treatment, yielding an interphase with a dense ZrOx outer layer and an underlying Zr-O-C network. Such a gradient organic-inorganic architecture is designed to facilitate selective Zn2+ ion transport while simultaneously blocking direct contact between Zn and the electrolyte, thereby mitigating corrosion, HER, and tip-enhanced dendritic growth. The optimized a-ZrOx-C coating layer (30 nm in thickness) on the Zn anode delivers a prolonged cell lifespan of over 1200 h at 1 mA cm-2, and the corresponding Zn||NH4V4O10 full cell maintains a high discharge capacity of 222 mAh g-1 after 300 cycles under 0.3 A g-1.