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

Abstract

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 Zn2+ diffusion kinetics limit their further application in ZIBs. Here, a novel and stable cathode (porous Na-V2O5) for aqueous ZIBs is rationally constructed by using a straightforward MOF-assisted synthetic method. The Na-V2O5 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-V2O5 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 Zn2+ and H+ co-intercalation/extraction-based energy storage method has been validated. This research may help rationally design layer-structured V2O5 cathodes for high energy and power density aqueous energy storage systems.