A surface engineering strategy for the stabilization of zinc metal anodes with montmorillonite layers toward long-life rechargeable aqueous zinc ion batteries

Rechargeable aqueous zinc-ion batteries (AZIBs) exhibit appreciable potential in the domain of electrochemical energy storage. However, there are serious challenges for AZIBs, for instance zinc dendrite growth, hydrogen evolution reaction (HER), and corrosion side reactions. Herein, we propose a surface engineering modification strategy for coating the montmorillonite (MMT) layer onto the surface of the Zn anode to tackle these issues, thereby achieving high cycling stability for rechargeable AZIBs. The results reveal that the MMT layer on the surface of the Zn anode is able to provide ordered zincophilic channels for zinc ions migration, facilitating the reaction kinetics of zinc ions. Density functional theory (DFT) calculations and water contact angle (CA) tests prove that MMT@Zn anode exhibits superior adsorption capacity for Zn2+ and better hydrophobicity than the bare Zn anode, thereby achieving excellent cycling stability. Moreover, the MMT@Zn||MMT@Zn symmetric cell holds the stable cycling over 5600 h at 0.5 mA cm−2 and 0.125 mA h cm−2, even exceeding 1800 h long cycling under harsh conditions of 5 mA cm−2 and 1.25 mA h cm−2. The MMT@Zn||V2O5 full cell reaches over 3000 cycles at 2 A g−1 with excellent rate capability. Therefore, this surface engineering modification strategy for enhancing the electrochemical performance of AZIBs represents a promising application.