Architecting V₂O₅ with a Triune Crystal Water–Amorphous–Crystalline Feature for Robust Zinc-Ion Batteries

Abstract

The notorious collapse of the electrode structure and strong electrostatic interactions in aqueous zinc-ion batteries (AZIBs) limit the achievement of a long cycle life. Herein, by designing an ordered/disordered hybrid structure, we have effectively preserved the integrity of the V₂O₅·1.6H₂O (VOH) electrode. Moreover, our approach facilitates the release of stress concentration contributed to by the amorphous component, alleviating the strong electrostatic interaction merited by crystal water and promoting the diffusion kinetics of Zn²⁺ assisted by the crystalline component. Noteworthy, the crystal water serves as an interlayer pillar significantly enhancing the structural stability of the electrode. As a result, our VOH electrode exhibits high electrochemical performance. It delivered 227.8 mAh g^-1 at a higher current density of 2 A g^-1, and a high cycle life of 1000 cycles with 95% capacity retention was achieved at a current density of 1 A g^-1.