Highly reversible plating/stripping in aqueous electrolytes is one of the critical processes determining the performance of Zn-ion batteries, but it is severely impeded by the parasitic side reaction and dendrite growth. Herein, a novel electrolyte engineering strategy is first proposed based on the usage of 100 mM xylitol additive, which inhibits hydrogen evolution reaction and accelerates cations migration by expelling active H2 O molecules and weakening electrostatic interaction through oriented reconstruction of hydrogen bonds. Concomitantly, xylitol molecules are preferentially adsorbed by Zn surface, which provides a shielding buffer layer to retard the sedimentation and suppress the planar diffusion of Zn2+ ions. Zn2+ transference number and cycling lifespan of Zn∥Zn cells have been significantly elevated, overwhelmingly larger than bare ZnSO4 . The cell coupled with a NaV3 O8 cathode still behaves much better than the additive-free device in terms of capacity retention.
Keywords: Cation Migration and Deposition; Hydrogen Bond; Xylitol Additive; Zn Dendrite; Zn-Ion Batteries.
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