Engineering Ferroelectric Dipole Superstructure via Phase Transformation for Stable Zinc Anodes

The commercialization of aqueous zinc ion batteries (AZIBs) is severely hindered by the thermodynamic instability of the Zn anode interface, which leads to uncontrollable dendrite growth and parasitic side reactions. While ferroelectric polymers like poly(vinylidene fluoride) (PVDF) show promise for regulating ion flux via their built-in electric field, the common α-phase PVDF exhibits random dipole alignment, resulting in a negligible macroscopic polarization effect. This work demonstrates that incorporating zinc sulfide (ZnS) as a multifunctional filler is an effective strategy to actuate a crucial phase transformation from the non-polar α-phase to the highly polar β-phase within the PVDF matrix. The resulting dipole-enhanced hybrid layer (DEHL) features a structure where β-phase nanocrystalline domains are aligned akin to "dipole superstructures," generating a strong and homogeneous built-in electric field. This field functions as an intelligent regulator, steering Zn2+ ions toward uniform nucleation and dense deposition while simultaneously repelling SO4 2- anions, thus synergistically suppressing zinc dendrites and inhibiting byproduct formation. Consequently, the DEHL-protected Zn anode (DEHL@Zn) achieves exceptional cycling stability over 1800 h in a Zn//Zn symmetric cell at 5 mA cm-2. When paired with NVO and I2 cathodes, the full batteries also deliver remarkable longevity, exceeding 2300 and 11 000 cycles with high specific capacities, respectively.