Ultrafast 3D Hybrid-Ion Transport in Porous V2O5 Cathodes for Superior-Rate Rechargeable Aqueous Zinc Batteries

Layered V2O5 is a star cathode material of rechargeable aqueous zinc-based batteries (RAZBs) owing to the rich redox chemistry of vanadium, which commonly exhibits the 2D ion-diffusion mechanism through Zn2+ (de)intercalation at edge sites but is plagued by the inert basal planes. Here, hierarchically porous V2O5 nanosheets vertically grown on carbon cloth (V2O5/C) are innovatively prepared, where the porous structure with lattice defects successfully unlocks the V2O5 basal plane to provide additional ion-diffusion channels and abundant active sites. Thus, highly efficient and ultrafast 3D Li+/Zn2+ co-insertion/extraction behaviors along both the c-axis and ab plane of V2O5 are realized for the first time in the formulated 15 m LiTFSI + 1 m Zn(CF3SO3)(2) aqueous electrolyte, as elucidated by systematic ex situ analyses, multiple electrochemical measurements, and theoretical computations. As a result, the porous V2O5/C electrode delivers an exceptional high-rate capability (up to 100 A g(-1)) and an ultralong cycling durability (15 000 cycles) in RAZBs. Finally, quasi-solid-state wearable rechargeable zinc batteries employing the porous V2O5/C cathode demonstrate respectable performance even under severe deformations and low temperatures. This work achieves a conceptual breakthrough represented by an upgrading of the traditional 2D ion transportation in layered cathodes to the more facile 3D diffusion for designing high-performance battery electrochemistry.

Automated summary

In this study, hierarchically porous V2O5 nanosheets vertically grown on carbon cloth were prepared, providing additional ion-diffusion channels and abundant active sites. The V2O5/C electrode exhibited exceptional high-rate capability and ultralong cycling durability in rechargeable aqueous zinc-based batteries. Moreover, the quasi-solid-state wearable zinc batteries employing the porous V2O5/C cathode demonstrated respectable performance even under severe deformations and low temperatures.