V-O-Ru Heterogeneous Interphase Reversible Reconstruction Endowing Zn_0.85V₁₀O₂₄·7.4H₂O/0.65RuO₂ Cathode Robust H⁺/Zn²⁺ Storage.

Abstract

Intercalation-type layered vanadium oxides have been widely explored as cathode materials for aqueous zinc-ion batteries (AZIBs). However, attaining both high power density and superior stability remains a formidable challenge. Herein, layered vanadium oxides are pre-intercalated with Zn²⁺ to form Zn_0.85V₁₀O₂₄·7.4H₂O (ZVO), which is then combined with RuO₂ nanoparticles to construct a ZVO/RuO₂ heterostructure featuring interphase V─O─Ru bonds. ZVO/RuO₂ heterostructure exhibits a dynamic stable coupling at the interphase via V─O─Ru chemical bonds reconstruction during discharging/charging processes. The dynamically reversible reconstruction of interphase V─O─Ru bonds provides a fast electron transfer channel between RuO₂ and ZVO cathode, as demonstrated by ex situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations, making RuO₂ an additional electron acceptor and donor, and accelerating the migration of H⁺/Zn²⁺ in layered ZVO cathode. Therefore, an ultra-high capacity (411 mAh g^-1 at 0.5 A g^-1, 225 mAh g^-1 at 20 A g^-1) and long cycling stability (a retention of 92.2% at 20 A g^-1 over 20000 cycles) performances are achieved. This interphase reversible reconstruction route provides a promising approach to achieving excellent cycling stability in cathode materials.