Cr₂O_3-x artificial interfacial layer featuring abundant nucleation sites: Facilitating rapid Zn²⁺ transport and highly reversible Zn anode

Interfacial engineering offers a promising solution to zinc anode instability, yet most studies focus solely on suppressing side reactions with water, overlooking the critical role of fast zinc ion kinetics. This work investigates the Cr₂O_3-x artificial interface layer, demonstrating its dual benefits of electrostatic shielding and enhanced Zn²⁺ transport kinetics. The Cr₂O_3-x layer exhibits excellent mechanical stability and hydrophilicity, with its negatively charged surface effectively repelling anions like SO₄²⁻ and OH⁻ to suppress side reactions. Moreover, the highly active Cr₂O_3-x layer accelerates Zn²⁺ migration, reduces nucleation energy barriers, and promotes uniform zinc deposition by facilitating Zn²⁺ detachment from solvated structures. As a result, the Cr₂O_3-x@Zn anode achieves exceptional cycling stability and remarkable reversibility, with symmetric batteries enduring over 1,800 h at 5 mA cm⁻². When paired with NH₄V₄O₁₀, it also demonstrates long cycle life and superior rate performance. This work sheds new light on the development of stable, high-performance zinc anodes.