Microgroove-patterned Zn metal anode enables ultra-stable and low-overpotential Zn deposition for long-cycling aqueous batteries

The application of zinc (Zn) metal in aqueous Zn metal batteries (ZMBs) has been hindered by the susceptibility of Zn anodes to dendritic electrodeposition due to its inhomogeneous surface structures. Herein, we design uniform microgroove patterns on practically accessible Zn foil anodes using a simple and scalable acid etching strategy. The unique surface structure guides homogeneous Zn deposition, accelerates interfacial reaction kinetics, and inhibits electrolyte corrosion. The resulting Zn anodes afford an excellent plating/stripping stability of 2920 h at an ultralow overpotential of 19.5 mV under 1 mA cm−2/1 mAh cm−2 cycling, with both the cycle life and overpotential ranking among the best records reported thus far. Moreover, the synergetic mechanisms for morphology-induced enhancement were rigorously elucidated. The present strategy contributes a reliable performance baseline for future studies, and can be readily combined with other emerging tactics such as surface coating to accelerate further performance upgrades towards practical ZMBs.