Ultrafast 3D Hybrid‐Ion Transport in Porous V<sub>2</sub>O<sub>5</sub> Cathodes for Superior‐Rate Rechargeable Aqueous Zinc Batteries
Tianhao Wang, Shengwei Li, Xinger Weng, Lei Gao, Yu Yan, Ning Zhang, Xuanhui Qu, Lifang Jiao, Yongchang Liu
Abstract
Abstract Layered V 2 O 5 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 Zn 2+ (de)intercalation at edge sites but is plagued by the inert basal planes. Here, hierarchically porous V 2 O 5 nanosheets vertically grown on carbon cloth (V 2 O 5 /C) are innovatively prepared, where the porous structure with lattice defects successfully unlocks the V 2 O 5 basal plane to provide additional ion‐diffusion channels and abundant active sites. Thus, highly efficient and ultrafast 3D Li + /Zn 2+ co‐insertion/extraction behaviors along both the c ‐axis and ab plane of V 2 O 5 are realized for the first time in the formulated 15 m LiTFSI + 1 m Zn(CF 3 SO 3 ) 2 aqueous electrolyte, as elucidated by systematic ex situ analyses, multiple electrochemical measurements, and theoretical computations. As a result, the porous V 2 O 5 /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 V 2 O 5 /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.