Atomic layer deposition assisted superassembly of ultrathin ZnO layer decorated hierarchical Cu foam for stable lithium metal anode

Abstract Lithium metal (Li) is regarded as the “holy grail” in the anode material of next-generation high-energy-density batteries. However, the Li dendrites and “dead Li” produced during cycling limit its commercialization process. A properly designed three-dimensional (3D) skeleton plays an important role in determining the performance of Li metal anodes (LMA). Herein, we develop a super-assembled surface-modified lipophilic thin ZnO layer by atomic layer deposition (ALD) and multi-level Cu nanofibers (MCN) on a Cu foam (ZnO-MCNCF) as an advanced Li metal anode host. During the Li plating process, lipophilic ZnO layer can induce uniform nucleation of Li. Meanwhile, the unique hierarchical structure provides a larger specific surface area to distribute the surface charge uniformly, adjust the current density, and ensure more uniform Li deposition. Consequently, the as-designed ZnO-MCNCF host enables dendrite-free deposition of Li, high coulombic efficiency, and remarkable cycling stability at various current densities. Compared with CF and MCNCF host, ZnO-MCNCF has significantly improved Li plating/stripping behavior, with high coulombic efficiency (CE) and excellent Li dendrite growth inhibition ability. The Li@ZnO-MCNCF electrode can be operated for 1400 h at a current density of 10 mA cm−2 and large area specific capacity of 10 mAh cm−2 with an ultra-low overpotential (57.1 mV) without significant fluctuations. The LiFePO4-Li (LFP-Li) and LiCoO2-Li (LCO-Li) full cells also exhibit superior cycling and rate performance.