Mott-Schottky Heterojunction Modulating Iron-Vanadium Oxide for High-Performance Aqueous Zinc Battery Cathodes.

Vanadium-based oxides have garnered significant attention for aqueous zinc batteries (AZBs), whereas sluggish Zn diffusion and structural collapse remain major challenges in achieving high-performance cathodes. Herein, different structures of iron-vanadium oxides were fabricated by modulating the amount of vanadium content. It is found that the porous Mott-Schottky heterojunction composed of FeVO and FeVO mixed phase was used to construct a self-generated FeVO-5 structure, which could lower the diffusion barrier and improve the electron transport derived from the formed built-in electric field at the interface, showing faster reaction kinetics and improved capacity compared with the singe-phase FeVO-1. Surprisingly, the FeVO-5 cathode delivers an impressive capacity of up to 431 mAh g at 0.6 A g, excellent rate capability (252.3 mAh g, 80 A g), and superior long-term cycling performance (95% capacity retention over 12 000 cycles at 40 A g). This work presents a reasonable strategy for engineering heterostructure materials for AZB application.