Mediating Triple Ions Migration Behavior via a Fluorinated Separator Interface toward Highly Reversible Aqueous Zn Batteries

Rampant dendrite growth, electrode passivation and severe corrosion originate from the uncontrolled ions migration behavior of Zn2+, SO42-, and H+, which are largely compromising the aqueous zinc ion batteries (AZIBs) performance. Exploring the ultimate strategy to eliminate all the Zn anode issues is challenging but urgent at present. Herein, a fluorinated separator interface (PVDF@GF) is constructed simply by grafting the polyvinylidene difluoride (PVDF) on the GF surface to realize high-performance AZIBs. Experimental and theoretical studies reveal that the strong interaction between CF bonds in the PVDF and Zn2+ ions enables evenly redistributed Zn2+ ions concentration at the electrode interface and accelerates the Zn transportation kinetics, leading to homogeneous and fast Zn deposition. Furthermore, the electronegative separator interface can spontaneously repel the SO42- and anchor H+ ions to alleviate the passivation and corrosion. Accordingly, the Zn|Zn symmetric cell with PVDF@GF harvests a superior cycling stability of 500 h at 10 mAh cm-2, and the Zn|VOX full cell delivers 76.8% capacity retention after 1000 cycles at 2 A g-1. This work offers an all-round solution and provides new insights for the design of advanced separators with ionic sieve function toward stable and reversible Zn metal anode chemistry. PVDF modified glass fiber separator (PVDF@GF) is developed to achieve high-performance aqueous zinc ion batteries (AZIBs) by repelling SO42-, alleviating proton activity and regulating Zn2+ transport and deposition behavior, enabling corrosion-free and dendrite-free Zn anodes, as well as long-term stability in Zn|VOX full batteries.image