Architecting a Hydrated Ca0.24V2O5 Cathode with a Facile Desolvation Interface for Superior-Performance Aqueous Zinc Ion Batteries

Vanadium-based materials are promising cathode candidates for low-cost and high-safety aqueous zinc-ion batteries (AZIBs). However, they suffer from inferior rate capability and undesirable capacity fading due to their intrinsic poor conductivity and structural instability. Herein, we synthesize hydrated Ca_0.24V₂O₅·0.75H₂O (CaVOH) nanoribbons with in situ incorporations of the carbon nanotubes via a one-step hydrothermal method, achieving an integrated architecture hybrid cathode (C/CaVOH) design. Benefitting from the robust structure and low desolvation interface, the prefabricated C/CaVOH cathodes deliver a high capacity of 384.2 mA h g^-1 at 0.5 A g^-1 with only 5.6% capacity decay over 300 cycles, enable an ultralong cycling life of 10,000 cycles at 20.0 A g^-1 with 80.2% capacity retention, and exhibit an impressive rate capability (165 mA h g^-1 at 40.0 A g^-1) with a high mass loading of ∼4 mg cm^-2. Moreover, through the theoretical calculations and a series of ex situ characterizations, we demonstrate the Zn²⁺/H⁺ co-intercalation storage mechanism, the key role of the gallery water, and the function of the induced C-O groups in promoting kinetics of the C/CaVOH electrode. This work highlights the strategy of in situ implanted high conductivity materials to engineer vanadium-based or other cathodes for high-performance AZIBs.