Constructing MOF-derived V2O5 as advanced cathodes for aqueous zinc ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have become incremental attention due to its low cost, material abundance and environmental friendliness. Unfortunately, the crucial challenge is to develop cathodes with satisfactory superior Zn2+ storage. Here, a hierarchical porous V2O5 nano-bulk (p-V2O5) was synthesized derived from vanadium-based metal-organic framework via carbonization as cathode for AZIBs. The hierarchical mesoporous structure and elevated specific surface area are conducive to promote ion/electron transport. The prepared cathode delivers a high specific capacity of 115 mAh g−1 even at 3 A g−1. We also demonstrate that the Zn2+ storage mechanism is a reversible Zn2+ insertion/extraction in the open-structured Zn3(OH)2V2O7·2H2O and ZnyV2O5·nH2O in the subsequent cycling. The distinguished Zn2+ storage performance makes p-V2O5 a potential cathode for the next generation AZIBs.