Interface engineering with zincophilic MXene for regulated deposition of dendrite-free Zn metal anode

Abstract

Dendrite growth and side reactions on zinc anodes have been the main problems hindering the commercialization of aqueous zinc-ion batteries (ZIBs). The construction of an interface protective layer (IPL) has proved to be one of the effective ways to improve the stability of zinc anodes, but it remains a challenge to achieve multi-functionality. Herein, tetramethylammonium-intercalated Ti3C2Tx MXene (MX-TMA) coating with a low zinc nucleation barrier was in-situ constructed on the surface of zinc foil by a facile self-assembly method. It provides the IPL with abundant zincophilic sites and better hydrophilicity, which promotes the transport of Zn2+ for uniform electrodeposition and inhibits interface side reactions. Moreover, the directional deposition of zinc on the beneficial (002) plane guided by MX-TMA is further revealed. As a result, the lifespan of the zinc electrode under 2 mA cm–2 is prolonged by 3600 h. Even under deep discharge (DODZn≈85%), the MX-TMA@Zn anode can still achieve stable cycles for more than 450 h. Furthermore, the full battery assembled with the Mn-based cathode also demonstrated superior performance. This work provides an in-depth mechanism analysis and inspiration for IPL design, thus advancing the development and practical application of ZIBs.