In-situ polymerization polyaniline-coating of V10O24·nH2O (VOH) for enhanced zinc-ion battery performance

Abstract

Recognized for their safety and low cost, aqueous zinc-ion batteries (AZIBs) hold significant promise for large-scale energy storage fields. Layered vanadium-based compounds offer attractive AZIBs cathodes with open crystal structures, high theoretical specific capacity, and resource abundance. However, they often suffer from vanadium dissolution and poor cycling stability caused by corrosion from free water molecules. To address these issues, polyaniline-coated V₁₀O₂₄·nH₂O (VOH@PANI) was synthesized via in-situ polymerization strategy. The conductive PANI coating not only enhances the electrical conductivity of composite, but also induces an amorphous structure transformation, thereby improving the rate capability. Furthermore, the polyaniline coating increases the material's hydrophobicity, effectively suppressing vanadium dissolution and enhancing electrochemical stability. Benefiting from this modification, the fabricated VOH@PANI-300 electrode delivers a specific capacity of 424.09 mAh g⁻¹ at 0.2 A g⁻¹ and maintains 314.51 mAh g⁻¹ after 1000 cycles at 5 A g⁻¹, corresponding to a capacity retention of 89.70 %. These results markedly surpass the uncoated VOH electrode (348.12 mAh g⁻¹ at 0.2 A g⁻¹, 39.62 % retention after 1000 cycles at 5 A g⁻¹. This work establishes a viable approach for preparing high-performance vanadium-based cathode materials of AZIBs.