Fabrication of Predominant β-Phase Poly(vinylidene fluoride) Protective Film for Zinc Anodes via Ion-Dipole Interaction for High-Stability Aqueous Zinc-Ion Batteries

Abstract

Rechargeable aqueous zinc-ion batteries (AZIBs) have emerged as a promising option for cost-effective and safe energy storage systems owing to the natural abundance of Zn, the use of aqueous electrolytes, the significant theoretical capacity of Zn metal, and their low negative potential. However, the electrolyte instability, dendrite formation, and risk of short circuits within these batteries hinder the efficient utilization of Zn. To address these, in this study, we fabricated a predominant beta-phase poly(vinylidene fluoride) (PVDF) using both thermal annealing and an ion-dipole interaction mechanism. Thereafter, the obtained PVDF was utilized as a protective layer for the Zn anode of the AZIBs. The predominant beta-phase PVDF-coated Zn (PBP@Zn) anode demonstrated exceptional performance, with a minimal overvoltage of 52 mV during 400 h of operation in symmetrical cell tests. Furthermore, the ZIBs exhibited increased capacity (259 mAh g(-1) at 0.3 A g(-1)) and rate capability (100 mAh g(-1) at 2.0 A g(-1)), while maintaining remarkable cycling stability. The remarkably enhanced cycling stability demonstrated by PBP@Zn underscores the robust reliability of AZIBs, making them highly suitable for real-world applications.