Operando constructing vanadium tetrasulfide-based heterostructures enabled by extrinsic adsorbed oxygen for enhanced zinc ion storage

Abstract

Enhancing the zinc ion storage ability of the existing cathodes is an important research field. Constructing the heterostructure is a promising and effective strategy. Interestingly, for oxygen-free cathodes, a nano-depth heterostructure layer will inevitably form on their surface when exposed to air. However, only the near-surface heterostructure interface cannot change their intrinsic zinc storage ability. Theoretically speaking, via constructing the bulk-type heterostructure with enough interfaces and grain boundaries, the intrinsic zinc storage ability of bulk cathodes can be effectively improved. Here, as a proof of concept, an operando conversion method to construct VS₄/V₂O₃ heterostructures enabled by the extrinsic adsorbed oxygen is proposed. The successful preparation of VS₄/V₂O₃ heterostructures is demonstrated via various characterization studies and analyses including X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, etc. Meanwhile, the obtained VS₄/V₂O₃ heterostructures deliver an enhanced zinc ion storage capacity of 164 mA h g⁻¹, rate performance and cycle stability. This operando construction approach enabled by extrinsic adsorbed oxygen provides a novel strategy to fabricate the functional heterostructure-based cathodes for multivalent ion batteries with high performance.