Construction of Robust Organic-Inorganic Interface Layer for Dendrite-Free and Durable Zinc Metal Anode

Constructing artificial interface layer is an effective approach to facilitate the utilization rate of zinc metal, but the practical application is still hindered by the inferior mechanical strength, low ionic conductivity, and poor stability. Herein, robust organic-inorganic layer (Nafion/BM@Zn) is coated on zinc metal through ultrasonic spraying method with boehmite and Nafion as the composite precursor. As demonstrated, the high cation selectivity and high hydrophilicity of Nafion, as well as the zincophilic property and layered structure of boehmite, synergistically contribute to the low nucleation barrier, uniform deposition, and fast transport kinetics of Zn2+ ions. As a result, the Nafion/BM@Zn anode exhibits superior reversibility with a high Coulombic efficiency of 99.9% for 9000 cycles in asymmetrical cells and durable cycling stability for 4200 h in symmetrical cells at 5 mA cm-2-1 mAh cm-2. Even in the seawater-based electrolyte, the Nafion/BM@Zn anode still displays reversible deposition behavior for 820 h and high Coulombic efficiency of 99.91% for 2800 cycles at 5 mA cm-2-1 mAh cm-2. Furthermore, the corresponding Nafion/BM@Zn//NH4V4O10 cell presents high capacity of 258.4 mAh g-1 after 1500 cycles at 5 A g-1. This work provides a new design strategy for high-efficiency interfacial layer of zinc metal anode. Robust organic-inorganic hybrid layer of Nafion and boehmite composite is constructed on the surface of zinc metal through ultrasonic spraying method to address the issues of dendrite growth and side reactions. Consequently, high cation selectivity of Nafion, and high zincophilic property of boehmite, contribute to the low nucleation barrier, uniform deposition, and fast transport kinetics of Zn2+ ions.image