Freestanding H2V3O8/MXene films for high performance quasi-solid-state zinc-ion batteries.

The H 2 V 3 O 8 /MXene film shows excellent electrochemical properties as cathode material for aqueous zinc-ion batteries and solid-state zinc-ion batteries. [Display omitted] • H 2 V 3 O 8 /MXene film has been synthesized by hydrothermal method and coating method. • Combination MXene and H 2 V 3 O 8 synergistically improves electrochemical properties. • The H 2 V 3 O 8 /MXene film shows excellent performance for AZIBs and solid-state ZIBs. In this study, freestanding H 2 V 3 O 8 /MXene (HVO/MX) film were synthesized by high temperature mixing hydrothermal method and coating method. The composite film exhibits good electrical conductivity and flexibility. In addition, HVO/MX film shows excellent electrochemical properties when used as cathode material for aqueous zinc ion batteries (ZIBs) and solid-state ZIBs. The aqueous ZIBs assembled from the HVO/MX film shows satisfactory specific capacity (highest specific capacity can reach 346 mAh/g at 10 A/g) and cycling performance. Surprisingly, the assembled quasi-solid-state batteries can work well at room temperature and low temperature conditions. The battery maintained a high discharge specific capacity of 180 mAh/g after 3000 cycles at 25 °C. The outstanding performance of the HVO/MX film assembled battery is due to its good electrical conductivity, zinc-ion diffusion rate and simple battery structure. This work provides a novel route for the preparation of self-supporting cathode materials for different battery system. [ABSTRACT FROM AUTHOR]