Al³⁺ Introduction Hydrated Vanadium Oxide Induced High Performance for Aqueous Zinc‐Ion Batteries

Abstract Aqueous zinc ion batteries are a promising alternative secondary battery technology due to their excellent safety and environmental friendliness. Vanadium‐based compounds as a highly promising class of cathode materials still suffer from structural collapse and slow kinetics. Studies have shown that metal ion pre‐introduction is an effective method to solve these problems and enhance battery performance. Here, the introduction of Al³⁺, Cr³⁺, Cu²⁺ and Fe³⁺ is found to effectively reduce the migration energy barrier of Zn²⁺ with the density functional theory calculations, while Al³⁺ exhibits the best induction effects. Subsequently, Al_0.34V₅O₁₂·2.4H₂O (AlVOH) nanoribbons are synthesized by hydrothermal introduction of Al³⁺, demonstratin excellent electrochemical properties (407.8 mAh g^‐1 at 0.2 A g^‐1 and 176.3 mAh g^‐1 after 2000 cycles at 20 A g^‐1). By further compounding with redox graphene (rGO), AlVOH/rGO exhibits high capacitance and specific capacity (460.4 mAh g^‐1 at 0.2 A g^‐1 and 180.6 mAh g^‐1 after 2000 cycles at 20 A g^‐1). In addition, it is found that the introduction of metal ions adjusts the structural water content of the material. Especially, the introduction of Al³⁺ can increase the interlayer structural water content and make the electrochemical properties of the material more stable.