Acid etching V2O5 nanowires cathode for high-performance zinc-ion full batteries

Abstract

Vanadium oxides are extensively utilized as cathode materials in aqueous zinc-ion batteries (AZIBs) due to the rich redox chemistry of vanadium, while their limited cyclability and sluggish diffusion kinetics impede the practical adoption. Herein, the structural engineering strategy via H₂SO₄ etching is proposed to modulate the morphology and electronic structure of V₂O₅ (termed as V₂O₅-H₂SO₄). Specifically, V₂O₅ etched H₂SO₄ features a staggered nanowire architecture and an increased V⁵⁺/V⁴⁺ ratio, contributing to improving structural stability and accelerating ion transport kinetics. The X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy reveal that the increased V⁵⁺ diminished Zn²⁺ diffusion barriers in V₂O₅-H₂SO₄, Modified the bonding architecture and furnish extra ion-diffusion channels and ample active sites, thus helping to elucidate the zinc storage mechanism and achieve the excellent electrochemical performance. V₂O₅-H₂SO₄ cathode exhibits an impressive energy output of 391.7 Wh kg⁻¹ at 152.66 W kg⁻¹. The assembled V₂O₅-H₂SO₄||CuZn₂/In/InZn₃@Zn full battery exhibits significantly augmented specific capacity of 588.4 mAh g⁻¹ at 0.2 A g⁻¹ and long-cycle stability. This research emphasizes the significance of acid etching on the structural engineering of AZIBs vanadium oxides cathode materials, providing a new approach for structural functional materials.