High-Performance Aqueous Zinc-Ion Batteries Enabled by Superlattice Intercalation Zn3V2O7-C Cathodes

Aqueous Zn-ion batteries (AZIBs) have received widespread attention for their advantages of environmental friendliness and high-safety, yet the development of high-performance AZIBs faces some critical issues, including exploring high-performance cathode materials with high electrical conductivity, high capacity, and stable crystal structures that may greatly affect the cycling stability and rate performance. Herein, we report a superlattice Zn 3 V 2 O 7 -C, which shows promising properties with high capacity and long-term stability as a conversion-type cathode material of AZIBs. The Zn||Zn 3 V 2 O 7 -C half-cells deliver a capacity of ∼210 mAh/g over 10, 000 charging/discharging cycles. A comprehensive investigation elucidates that the superlattice Zn 3 V 2 O 7 -C can provide more reactive sites, more stable structure, and more enhanced electrical conductivity for Zn 2+ storage, thus benefiting the promotion of Zn 2+ electrochemical and diffusion kinetics. The favorable characteristics of the designed cathode will pave an avenue for the development of promising electrodes for practical AZIBs.