Construction of a self-supported dendrite-free zinc anode for high-performance zinc–air batteries

Abstract

Zinc-anode-based batteries are widely used in energy storage devices due to their low cost, high-energy density, and environmental friendliness. However, the fatal dendrite growth of the zinc anode during cyclic plating and stripping processes severely affects the service life of the batteries. Herein, a ZIF-8-derived Zn-ZnO@C-550 anode, i.e. ZnO nanoarrays grown in situ on the surface of zinc foil via chemical deposition followed by hydrothermal synthesis and annealing, is designed for zinc–air batteries. With this prepared self-supported anode, the assembled zinc–air battery exhibits excellent discharge performance (995.77 mA h) compared to the same size of zinc foil, and remarkable cycling performance (more than 1200 cycles at a large current density of 10 mA cm⁻²) with dendrite growth being suppressed. The superior anti-dendritic properties of the fabricated Zn-ZnO@C-550 anode can be attributed to the highly ordered array structure of the Zn anode, which allows a homogeneous zinc ion concentration to avoid the growth of metallic zinc clusters, as confirmed by a simulation of the electrode current density distribution. The reversibility of Zn²⁺ plating/stripping in this work provides a promising strategy for preparing a dendrite-free metal anode of these Zn-related batteries.