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

Abstract

AbstractRampant 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 C─F 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.