Regulating "Tip Effect" and Zn2+-Deposition Kinetics by In Situ Constructing Interphase for Low Voltage Hysteresis and Dendrite-Free Zn Anode.

Abstract

Metal zinc (Zn) is being explored as a possible anode for aqueous zinc ion batteries (AZIBs). However, unrestrained Zn dendrite caused by "tip effect" and chemical corrosion continue to plague the Zn deposition process, limiting the functionality of AZIBs and prohibiting their use at high current densities. This work presents an in situ approach for introducing homogeneous ZnO nanoarrays onto the surface of Zn foil (Zn@ZnO NAs) as a functional protective interphase. On the one hand, well-distributed ZnO NAs protection layer can regulate the "tip effect" and confine the growth of Zn dendrite. On the other hand, the ZnO NAs layer can enhance the desolvation and diffusion process of Zn2+ on the surface of anode, attributing to low voltage hysteresis and exceptional electrochemical performance at high current densities. As a result, the Zn@ZnO NAs exhibits a low voltage hysteresis of 50.8mV with a superb lifespan of 1200h at a current density of 5mA cm-2. Moreover, Zn@ZnO NAs||α-MnO2 full-cell shows a superior cycling performance after 500 cycles at 0.5 A g-1 with a capacity of 216.69 mAh g-1. This work is expected to provide ideas for designing other reversible zinc anode chemical systems, especially under a high current density.