Synthesis of Zn2+-Pre-Intercalated V2O5•nH2O/rGO Composite with Boosted Electrochemical Properties for Aqueous Zn-Ion Batteries

Layered vanadium-based materials are considered to be great potential electrode materials for aqueous Zn-ion batteries (AZIBs). The improvement of the electrochemical properties of vanadium-based materials is a hot research topic but still a challenge. Herein, a composite of Zn-ion pre-intercalated V2O5 center dot nH(2)O combined with reduced graphene oxide (ZnVOH/rGO) is synthesized by a facile hydrothermal method and it shows improved Zn-ion storage. ZnVOH/rGO delivers a capacity of 325 mAh.g(-1) at 0.1 A.g(-1), and this value can still reach 210 mAh.g(-1) after 100 cycles. Additionally, it exhibits 196 mAh.g(-1) and keeps 161 mAh.g(-1) after 1200 cycles at 4 A.g(-1). The achieved performances are much higher than that of ZnVOH and VOH. All results reveal that Zn2+ as pillars expands the interlayer distance of VOH and facilitates the fast kinetics, and rGO improves the electron flow. They both stabilize the structure and enhance efficient Zn2+ migration. All findings demonstrate ZnVOH/rGO's potential as a perspective cathode material for AZIBs.

Automated summary

In this study, a composite of Zn-ion pre-intercalated V2O5·nH2O combined with reduced graphene oxide (ZnVOH/rGO) is synthesized to improve the Zn-ion storage of vanadium-based materials. ZnVOH/rGO shows enhanced performances, with high capacity and stability, making it a promising cathode material for aqueous Zn-ion batteries.