Regulating the Polarization of Lithium Metal Anode via Active and Inactive 3D Conductive Mesh Structure

Lithium is spotlighted as the next-generation battery anode owing to its low potential and high theoretical capacity. However, the volume changes and dendrite issues hinder its practical use as an anode material. Several metallic protective layers are used to overcome these problems. However, a comprehensive understanding of the material properties and structure of protective layers within an electric field is required to determine their suitability as protective layers. Herein, the reactivity with the Li of copper and stainless steel (SS) meshes within the electric field is compared, which are active and inactive protective layers, respectively. As inactive materials do not influence the Li-ion chemistry, the protective layer minimizes Li consumption. These characteristics lead to reducing the anodic polarization because of stable solid electrolyte interface (SEI) layer formation and effective utilization of the host space. A Li–Li symmetric cell configuration containing SS mesh as a protective layer exhibits stable cycling performance with a low overpotential (20 mV) for over 800 h at a current density of 1 mA cm⁻². Furthermore, the SS mesh inhibits the galvanic corrosion between the Li metal anode and mesh layer because of its low reactivity with lithium.