Epitaxial growth of the (101) plane: High stability and dendrite-free Zn anode achieved by “one stone, two birds” strategy

Abstract

The performance of zinc ion batteries (ZIBs) is significantly constrained by dendrite growth and side reactions on the Zn anode. While epitaxial growth is an efficient strategy to stabilize the Zn anode by directing crystal alignment, the direct contact between the exposed crystal and electrolyte results in severe parasitic reactions. Here, we present a selective etching strategy on Zn anodes (denoted as ACE-Zn) that preferentially exposes the (101) plane, which features strong epitaxial growth characteristics to facilitate stably dense stacking of Zn atoms. Notably, the (101) plane also promotes the formation of a ZnS solid electrolyte interphase (SEI). This ZnS SEI exhibits high hydrophilicity and an ultrathin structure, contributing to exceptional ion transfer rate and isolating the Zn anode from water-related side reactions. As a result, ACE-Zn symmetric cells achieve an impressive cycle life of 4920 h at 0.5 mAh cm⁻² and 0.5 mA cm⁻², along with a high average Coulombic efficiency (CE) of 99.93 % over 3500 cycles. Furthermore, V-EG//ACE-Zn button-cells demonstrate prolonged cycle life of 7600 cycles at 10 A g⁻¹. We believe this “one stone, two birds” strategy will provide new insights into texturing preferential planes and constructing SEI to stabilize Zn anodes.