Amorphization‐Induced Storage Mechanism Transition in Vanadium Oxide Cathodes for Aqueous Batteries

ABSTRACT

Aqueous zinc‐ion batteries (AZIBs) are promising post‐lithium energy storage devices, yet their advancement depends on developing high‐performance cathode materials. Vanadium oxides are attractive candidates but suffer from limitations such as low conductivity and structural instability. While modulation strategies have been explored, the fundamental impact of the crystallinity on ion storage mechanisms remains unclear. This study elucidates this relationship by synthesizing both crystalline and amorphous vanadium oxides and reveals that the amorphous cathode delivers a superior specific capacity (∼297 mAh g ⁻¹ ), exceptional rate capability, and long‐term cycling stability (92.3% retention after 1200 cycles). Through spectroscopic tracking and theoretical calculations, it is demonstrated that the amorphous structure provides a flexible framework that preferentially facilitates reversible Zn‐ion insertion/extraction. In contrast, the ordered crystalline lattice favors H ⁺ transport and exhibits limited reactivity with Zn ions. Hence, this work establishes a direct link between structural amorphization and enhanced Zn‐ion storage kinetics, providing a highly effective and broadly applicable design strategy for optimizing electrode materials in AZIBs.