Enabling and Boosting Preferential Epitaxial Zinc Growth via Multi-Interface Regulation for Stable and Dendrite-Free Zinc Metal Batteries

The practical application of aqueous Zn-metal anodes (AZMAs) is mainly impeded by the short cycling life and unsatisfactory reversibility springing from the notorious Zn dendrite growth and detrimental water-induced parasitic reactions at anode-electrolyte interface. To tackle these challenges, a multifunctional interface of Sn-modified Ti3C2Cl2 MXene (denoted as Sn-MXene) with high zincophilic and hydrophobic properties is rationally designed via a 1-step strategy with a novel molten salt etching to achieve dendrite-free Zn deposition. Experimental results and theoretical calculations reveal that the Sn nanoparticles can induce a strongly zincophilic surface with high Zn2+ adsorption, and the Ti3C2Cl2 MXene significantly decreases the surface energy of the Zn (002) plane, guiding the zinc-preferred orientation along the (002) plane in the electroplating growth process. Moreover, the hydrophobic properties of -Cl terminations of the protective interface for the Zn anode can regulate Zn-ion solvation structure to mitigate H2O-decomposition-induced side reactions, and guarantee a steady stream of Zn2+ flux. Encouragingly, benefiting from the Sn-MXene layer, a side reaction-free and dendrite-free Zn anode with an excellent lifespan is achieved, which is further applied as an anode for full battery (Sn-MXene-Zn//alpha-MnO2) with a long-term span over 800 cycles under 1 A g(-1) with a capacity retention of 96%.