Unlocking Ultrafast-Kinetics Asymmetric Heterojunction with Multi-Anionic Redox Chemistry Enables High Energy/Power Density and Low-Temperature Zinc-Ion Batteries.

The development of high-performance Zn-ion batteries is hindered by sluggish reaction kinetics and inadequate redox activity in conventional vanadium-based cathodes. Herein, a thermal oxidation phase-engineering strategy is proposed to construct a comprising VSSe core and oxygen-enriched VO and VO interfaces triple-phase heterojunction cathode. This unique architecture leverages a significantly increased specific surface area, which facilitates rapid electrode-electrolyte interactions and boosts pseudocapacitive contributions. This integrated structure, featuring optimized coordination environments and interfaces, promotes synergistic multi-anionic (S/Se/O) and cationic (V) redox activity and facilitates efficient charge transfer across the interfaces, overcoming intrinsic limitations of capacity and structural instability often observed in single-phase materials, especially during prolonged cycling. This optimized cathode achieves a record-high reversible capacity of 432 mAh g at 1 A g, surpassing mild-oxidized and over-oxidized VSSe counterparts. Remarkably, it retains 80% capacity after 14 000 cycles at 30 A g under cryogenic conditions of -10 °C, demonstrating unprecedented low-temperature durability. The structure-function relationship of heterojunction is driven by enhanced p-d orbital hybridization and spin polarization effects at the heterointerfaces, contributing to the improved redox activity and kinetics. This work establishes a design paradigm for engineering multi-phase heterojunction electrodes with tailored surface area and interfacial properties for next-generation energy storage systems.