Enhancing ion shuttling through hydrogen bonding effect in ZnV₂O₄ aqueous zinc ion battery cathode

Layered vanadium oxide materials exhibit significant multielectron redox reactions and regulatable transfer channels for Zn²⁺ insertion/extraction in rechargeable aqueous zinc-ion batteries (AZIBs). However, vanadium dissolution poses a severe challenge to achieving stable performance in AZIBs. In this work, we report an in-situ polymerization of polyaniline (PANI) on ZnV₂O₄ (ZVO) materials, resulting in a cross-interlocked nanosheet morphology to inhibit vanadium dissolution. The high conductivity and unique π-conjugated structure of PANI effectively weaken the electrostatic interactions between Zn²⁺ and the V-O layers, thereby enhancing the diffusion of Zn²⁺ at the electrode material interface, suppressing the vanadium dissolution of ZnV₂O₄ and stabilizing its structure framework. Concurrently, density functional theory (DFT) calculations further confirm that PANI can significantly modulate the electronic properties of the ZVO matrix. PANI forms robust hydrogen bonds with ZVO, resulting in an abundance of free Zn ions within the system, which accelerates electron/ion transfer kinetics, thereby enhancing the efficient storage performance of Zn²⁺ and increasing specific capacity. The ZVO@PANI composite electrode exhibits high specific capacity (706.4 mAh g⁻¹ at 0.1 A g⁻¹), remarkable rate capability (350.2 mAh g⁻¹ at 5 A g⁻¹), and robust cycling performance. This study provides a reasonable strategy for designing high-performance cathode materials for aqueous zinc-ion batteries.