Dual-functional zincophilic–hydrophobic interfacial layer enables highly stable Zn metal anodes

Abstract

Aqueous Zn-ion batteries (AZIBs) deliver outstanding potential as next-generation energy storage systems due to the attractive merits of inherent safety and low cost. However, uncurbed dendrite growth and non-negligible water-induced side reactions can be fatal to the stability of Zn anodes and the commercial development of AZIBs. Herein, we construct a bifunctional zincophilic–hydrophobic interfacial layer (STA-ZnO layer) for attaining a stable Zn anode. Exposed hydrophobic alkyl chains can repel H₂O to prevent it reaching the Zn foil surface, effectively alleviating the HER and corrosion side reactions. Meanwhile, the zincophilic ZnO ensures that the STA-ZnO@Zn anode accelerates Zn²⁺ deposition and constrains the growth of Zn dendrites. Benefitting from these advantages, symmetric cells based on the STA-ZnO@Zn anode can deliver long-term cycling stability over 4900 h and 4000 h at 1 mA cm⁻² and 5 mA cm⁻² for 1 mAh cm⁻², respectively. Encouragingly, the STA-ZnO@Zn anode also exhibits a high average CE of 99.81% (2000 cycles). This work develops a feasible strategy to protect Zn anodes for achieving the practical application of AZIBs.