CF_X Coating Enables Highly Reversible Zn Metal Anode

Rechargeable aqueous Zn-ion batteries (AZIBs) have garnered significant interest owing to their safety, economic advantages, and environmental protection. However, Zn dendrite growth and undesirable side reactions significantly limit the practical use of ZIBs. Herein, a fluorinated graphite (CFx) and polyvinylidene fluoride (PVDF) composite interface layer was introduced to enhance the cycling stability of the zinc anode. By coating the Zn anode with a hydrophobic CFx-PVDF composite interface layer, the direct contact between the Zn anode and H2O molecules was prevented, thus inhibiting dendrite growth and side reactions concurrently. Thus, the growth of Zn dendrites was effectively suppressed with restricted Zn2+ 2D diffusion and limited side reactions. In addition, the symmetric cells achieved stable cycles and a lifespan exceeding 1400 h at 5 mA cm–2 and 1 mA h cm–2, significantly outperforming the performance of the cells with a bare Zn anode. The capacity retention rate of CFx-PVDF@Zn || NH4V4O10 was 71.8% after 1000 cycles, which showed an excellent cycle ability.