A Physical Approach to Practical Applications of Lithium Metal Anode Using High-Flatness Cu Mesh Inducing Epitaxial Li Plating for All Solid-State Battery

Lithium metal batteries (LMBs) have been highlighted as next-generation energy storage systems due to their high energy density. However, dead Li and dendritic Li, induced by the large volume change of Li and inhomogeneous Li + flux during Li plating/stripping, hinder the practical application of the LMBs. Especially, the copper foil, which serves as a two-dimensional substrate, increases the local current density and forms sharp Li nuclei due to its poor lithiophilicity. Furthermore, spatially varying surface kinetics induce repetitive volume expansion, resulting in the rupture of the solid electrolyte interface and reduced battery cycle stability. Therefore, numerous papers introduced 3D hosts (mesh, foam, gauze, and coil) to induce the dense Li deposition via reducing the local current density. In addition, the mechanically stable and spacious structure of 3D hosts easily accommodates the internal stress fluctuation and homogenizes spatially varying surface kinetics. Although these strategies effectively increase the safety and lifespan of LMBs, they are still impractical due to the large thickness and the long manufacturing time of the 3D-hosted lithium metal anode (LMA). Herein, we report a facile physical approach to the fast fabrication of thin and lightweight 3D LMAs with ultralong cycle stability. The pressed Cu mesh (PCM) using a simple roll-pressing process could be fabricated speed of 0.2 m 2 min − 1 and easy to scale up. In particular, the shape of the Cu wire had been modified from round to flat to enhance the lithiophicity. Therefore, the PCM uniformly coated with molten lithium (PCM-Li) achieved a thickness of 38 μm and a light weight of 11.9 mg cm −2 . In symmetrical cell evaluation under 1mAh cm − 2 @1mA cm − 2 , the PCM-Li showed an ultrastable overpotential of 9.6 mV over 1,000 cycles. Furthermore, the PCM-Li maintained stable voltage behavior for more than 600 h even under 5mAh cm −2 @5mA cm −2 . Interestingly, in the SEM image of the PCM-Li after 1,000 cycles, no mossy or dendritic Li was observed, as Li was epitaxially plated along the flat Cu wires. Finally, we assembled a 1-Ah-scale high-energy LMB (351 Wh kg − 1 ) with the PCM-Li anodes and dry-coated NCM811 cathodes to demonstrate practical application. The LMB using the PCM-Li represented excellent practicality showing capacity retention of 80% during 200 cycles. This facile physical approach is helpful to the commercialization of next-generation lithium-based batteries and broa