Structural and electronic co-regulation of Ag@MXene-VOH heterostructures for durable aqueous zinc-ion batteries

Hydrated vanadium pentoxide (VOH) is regarded as a promising cathode material for aqueous zinc-ion batteries (AZIBs) owing to its open layered framework and multivalent redox chemistry. However, its practical application is limited by sluggish charge-transfer kinetics and structural instability during repeated Zn²⁺/H⁺ insertion and extraction. Herein, an integrated AgNP@MX-VOH composite cathode is constructed by coupling VOH nanorods with Ag nanoparticle-decorated Ti₃C₂Tₓ MXene. The flexible MXene sheets provide continuous electron-transport pathways and bridge neighboring VOH nanostructures, while the dispersed AgNPs act as local conductive contact nodes and regulate the stacking configuration of the MXene assembly. This hierarchical interfacial network helps suppress MXene restacking, maintain accessible porous regions, and improve the structural and electrical stability of the conductive framework. Meanwhile, the formation of the AgNP@MX-VOH heterointerface modifies the local electronic environment of VOH, accompanied by an increased V⁴⁺ contribution and enhanced oxygen-defect-related features.These structural and interfacial effects facilitate charge transfer and reversible ion-storage kinetics while maintaining electrode integrity during cycling. Consequently, the AgNP@MX-VOH cathode delivers a high reversible capacity of 361.2 mAh g⁻¹ at 0.5 A g⁻¹ , a capacity of 268.96 mAh g⁻¹ at 5 A g⁻¹ , and 90.2% capacity retention after 1000 cycles at 5 A g⁻¹ . This work provides an interfacial-engineering strategy for constructing stable MXene/vanadium-oxide heterostructures toward durable aqueous zinc-ion storage.