In situ engineering of a glutathione-derived hydrophobic layer for durable and dendrite-free Zn anodes

Aqueous Zn-ion batteries (AZIBs) are gaining increasing attention for large-scale energy storage due to their cost-effectiveness, safety, and high volumetric energy density. However, their practical application is still hindered by challenges such as uncontrolled growth of Zn dendrites and unwanted side reactions. In this study, we introduce an interfacial engineering strategy by applying a glutathione (GSH) functional layer on the surface of the Zn anode (GSH@Zn). The GSH layer not only mitigates corrosion by increasing the hydrophobicity of Zn anodes but also guides uniform Zn deposition. Moreover, the native oxides on Zn anodes are etched by glutathione, resulting in an increased electrochemical active area and reduced interfacial impedance, which improves reaction kinetics. Therefore, the GSH@Zn anode demonstrates stable, long-term plating/stripping cycling, operating dendrite-free for 4500 h at 1 mA cm^-2, significantly outperforming bare Zn anodes, which short-circuit after only 130 h. When paired with a vanadium-based cathode, the full cell shows excellent cycling stability and rate capability, retaining 86 % of its capacity after 2000 cycles and releasing 60 % of its capacity at 4 A g^-1. This work offers an effective strategy to enhance the stability and reversibility of Zn anodes in aqueous electrolytes, laying the groundwork for the development of durable, high-performance Zn-based energy storage systems.