Arrays of Hierarchical Zincophilic Nanorods with Trapping‐and‐Leveling Deposition for Ultrastable Zn Metal Anodes

Abstract

AbstractRechargeable aqueous zinc‐ion batteries (ZIBs) are highly promising for large‐scale sustainable energy storage applications, but there remain serious problems such as Zn dendrites and side reactions that limit the cycling performance. Herein, arrays of core–shell nanorods on Cu foam are developed to stabilize zinc anodes, which have a hierarchical topological structure consisting of N‐doped carbon layers embedded with a zincophilic component of Cu5Zn8 alloy (Cu5Zn8@NC). It is found that the inner Cu5Zn8 alloys have minimized nucleation barriers and act as preferred nucleation sites, and the hierarchical arrays provide the protective layers to further accommodate the high‐capacity plating Zn, leading to a trapping‐and‐leveling process of Zn deposition. The as‐obtained Zn layers play an important role in homogenizing the interfacial ionic fluxes and reducing the local current densities. As a result, the optimized Cu5Zn8@NC host yields a superb Coulombic efficiency of 99.7% over 5000 plating/stripping cycles, and the corresponding symmetric cell delivers an ultralong dendrite‐free cycle life of 7000 h with a low overpotential of 16.5 mV at 1 mA cm−2 and 1 mAh cm−2. The ZIB assembled with the zinc anode and a V2O5 cathode exhibits long‐term charging/discharging cycles as well, up to 89.2% capacity retention after 10 000 cycles.