Na+ Intercalated V2O5 Derived from V-MOF as High-Performance Cathode for Aqueous Zinc-Ion Batteries

Layered vanadium oxides have been considered as highly promising cathode materials for aqueous zinc-ion batteries (ZIBs) due to their unique open crystal structure and high theoretical specific capacity. However, the structural instability and sluggish Zn 2+ diffusion kinetics limit their further application in ZIBs. Here, a novel and stable cathode (porous Na-V 2 O 5 ) for aqueous ZIBs is rationally constructed by using a straightforward MOF-assisted synthetic method. The Na-V 2 O 5 exhibits remarkable capacity of 306 mAh g −1 at 0.1 A g −1 , exceptional rate characteristics (264.3 mAh g −1 at 2.0 A g −1 ), and great cycling capabilities over 1000 cycles with a capacity-retention of 83.4% when examined as a cathode for ZIBs. Higher pseudo-capacitance, quicker charge-transfer/ion-diffusion kinetics, and a robust architecture have been attained in the Na-V 2 O 5 cathode, which are in charge of the superior zinc-ion storage performance. This has been made possible by the pre-intercalated Na + cations and the resulting layer structure. Additionally, the Zn 2+ and H + co-intercalation/extraction-based energy storage method has been validated. This research may help rationally design layer-structured V 2 O 5 cathodes for high energy and power density aqueous energy storage systems.