Construction of a Composite Sn-DLC Artificial Protective Layer with Hierarchical Interfacial Coupling Based on Gradient Coating Technology Toward Robust Anodes for Zn Metal Batteries

Developing a robust zinc (Zn) anode, free from Zn dendrites and unwanted side reactions, relies on designing a durable and efficient interfacial protection layer. In this study, gradient coating technology is employed to construct a hierarchically structured composite of Sn with diamond-like carbon (DLC/Sn-DLC) as an artificial protective layer. The DLC framework endows DLC/Sn-DLC layer with high stability and adaptability, achieving long-term stability of the anode-electrolyte interface. The gradual-composite Sn, with its Sn & horbar;O & horbar;C interface chemical bonds, facilitates rapid charge transfer and offers ample zincophilic sites at the base, promoting uniform Zn2+ reduction reaction and deposition. Additionally, the DLC/Sn-DLC composite exhibits a "lotus effect" and favorable hydrophobic properties, preventing water-reduced side reactions. Leveraging this structural design and the synergistic cooperation of DLC and Sn, the DLC/Sn-DLC@Zn electrode demonstrates remarkable Zn plating/stripping reversibility, eliminating Zn dendrites and side reactions. Notably, under a high current density of 10 mA cm-2, the DLC/Sn-DLC@Zn anode-based symmetrical cell exhibits stable operation for over 1550 h, with a low nucleation overpotential of 101 mV. The DLC/Sn-DLC@Zn||Mn3O4-CNTs full battery delivers a high capacity of 109.8 mAh cm-2 after 5800 cycles at 2 A g-1, and the pouch cell shows potential for energy storage applications. A composite Sn-DLC artificial protective layer for Zn metal anodes with hierarchical interfacial coupling is constructed based on gradient coating technology. The chemically inert DLC with abundant Sn & horbar;O & horbar;C interface chemical bonds and unique micro-nano structure, which enable the layer with high stability and rapid reaction kinetics, thus achieving highly reversible Zn plating/stripping and eliminated water induced side effects. image