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

Abstract

AbstractLayered 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.