Organic-inorganic coordination engineering of vanadium oxide cathodes: From interfacial chemistry to practical zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage due to high safety, low cost, and environmental friendliness. Vanadium oxides are attractive cathodes because of their open frameworks, multiple oxidation states, and high theoretical capacities, but they suffer from poor conductivity, structural instability, vanadium dissolution, and by-product accumulation. This review systematically elucidates the mechanistic roles of organic molecular engineering in modulating the vanadium oxide interlayer microenvironment. Unlike previous reviews, which either emphasize specific composite strategies or organic modification methods without offering a systematic framework, our classification organizes existing organic intercalating agents into six categories based on molecular structural features and intercalation driving forces. Ranging from simple organic ammonium cations to complex polymers, this taxonomy enables direct comparison of structure–performance relationships across molecular families. For each category, we discuss synergistic regulation mechanisms, including expanded interlayer spacing to facilitate ion diffusion, enhanced electronic conductivity via charge transfer, electrostatic shielding to stabilize layered structures, and suppressed vanadium dissolution through coordination or protective effects. We further identify key challenges, namely limited cycling stability and unresolved dynamic mechanisms, and suggest solutions including advanced characterization and computational modeling. Future advances are envisioned through the design of novel multifunctional molecules, the development of green and scalable synthesis routes, and a deeper mechanistic understanding of dynamic intercalation processes, all of which are expected to accelerate the practical deployment of AZIBs.