Large-area hydrated vanadium oxide/carbon nanotube composite films for high-performance aqueous zinc-ion batteries

Synchronously reducing/self-assembling strategy on Zn substrate was designed to fabricate large-area cation-doped hydrated V 2 O 5 /multi-walled carbon nanotube (D-HVO/MWCNT) composite films. Interestingly, the Zn 2+ ions are simultaneously doped in hydrated V 2 O 5 during the assembly process, which will be beneficial to the high electrochemical performance of hydrated V 2 O 5 . By further combining 3D conductive MWCNT network, the freestanding D-HVO/MWCNT composite films display high capacity, excellent rate capability, and remarkable long-term cycling performance (up to 10,000 cycles with a high capacity retention of 98.5%). Moreover, owing to the high conductivity and flexibility of the D-HVO/MWCNT composite films, the soft-packaged aqueous zinc-ion batteries (ZIBs) were constructed based on such composite films. The devices exhibit stable electrochemical performance even under different bending states. Therefore, such a strategy provides a promising route to achieve large-area carbon and metal oxides-based composite films with high performance and good flexibility.