Water‐Lubricated Intercalation in V2O5·nH2O for High‐Capacity and High‐Rate Aqueous Rechargeable Zinc Batteries

Low-cost, environment-friendly aqueous Zn batteries have great potential for large-scale energy storage, but the intercalation of zinc ions in the cathode materials is challenging and complex. Herein, the critical role of structural H₂ O on Zn²⁺ intercalation into bilayer V₂ O₅ ·nH₂ O is demonstrated. The results suggest that the H₂ O-solvated Zn²⁺ possesses largely reduced effective charge and thus reduced electrostatic interactions with the V₂ O₅ framework, effectively promoting its diffusion. Benefited from the "lubricating" effect, the aqueous Zn battery shows a specific energy of ≈144 Wh kg^-1 at 0.3 A g^-1 . Meanwhile, it can maintain an energy density of 90 Wh kg^-1 at a high power density of 6.4 kW kg^-1 (based on the cathode and 200% Zn anode), making it a promising candidate for high-performance, low-cost, safe, and environment-friendly energy-storage devices.