In Situ Polymerized Polyaniline Coating on Na ₅ V ₁₂ O ₃₂ Nanobelts for Enhanced Cycling Stability in Aqueous Zinc‐Ion Batteries

Vanadium‐based compound cathodes have received considerable attention for aqueous zinc‐ion batteries (AZIBs) owing to their high specific capacity, multiple valence states, and versatile structural features. However, the dissolution and severe structural degradation of vanadium‐based cathodes during repeated insertion/extraction of Zn ²⁺ result in rapid capacity decay, hindering their development. To address these challenges, polyaniline (PANI)‐coated Na ₅ V ₁₂ O ₃₂ nanobelt cathodes (NVOP‐3) are developed via hydrothermal synthesis combined with in situ polymerization. The in situ‐grown PANI coating constructs a dual‐functional interface that stabilizes the vanadium oxide framework, prevents its dissolution, and enhances zinc‐ion diffusion kinetics. When applied as a cathode for AZIB, the obtained compound delivered a high reversible capacity of 301.5 mAh g ⁻¹ at 0.1 A g ⁻¹ , along with remarkable cycling stability‐retaining 92.5% of its capacity after 1000 cycles at 2 A g ⁻¹ , surpassing most reported vanadium‐based cathodes. This interfacial engineering strategy offers novel insights for developing robust AZIB cathodes toward practical applications.