Aerogel-Derived VO2/V2O5 Heterointerfaces for High-Rate Aqueous Zinc-Ion Batteries

Vanadium oxides are promising cathode materials for aqueous zinc-ion batteries (AZIBs) due to their low cost, high theoretical capacity, and multivalent redox chemistry. However, their intrinsically low electronic conductivity and sluggish reaction kinetics severely limit rate capability and long-term cycling stability. This study proposes an aerogel-driven strategy to construct VO2/V2O5 heterostructured cathodes (denoted as Vs-V2O5) with a hierarchically porous architecture. The aerogel-derived framework provides a large surface area and continuous ion-diffusion pathways, effectively shortening Zn2+ transport distances. Meanwhile, vapor-phase hydrothermal treatment induces the in situ formation of VO2/V2O5 heterostructured regions via partial reduction of the aerogel precursor. These heterostructured regions induce local electronic redistribution, which may contribute to interfacial charge regulation, while the porous and hydrated aerogel framework improves electrolyte accessibility and ion-transport kinetics. Benefiting from the synergistic effects of the aerogel-derived porous structure, hydrated/open framework, and favorable electrode kinetics, the Vs-V2O5 cathode exhibits reduced polarization and enhanced rate capability even at high current densities, delivering a specific capacity of 342 mAh g-1 at 1.0 A g-1 and retaining 87% of its capacity after 7500 cycles at 20 A g-1. This study provides an effective and scalable strategy for designing high-rate vanadium oxide cathodes for AZIBs, offering practical guidance for the development of advanced aqueous energy-storage systems.