Designing Lithophilic Interfaces for Robust Anode-Free Lithium Metal Batteries

Anode-free lithium metal batteries (ALMBs) require lithophilic surfaces to enable uniform and reversible lithium plating and stripping. Herein, a unique method is employed to engineer the surface of copper (Cu), commonly used as a current collector in ALMBs. One side of the Cu foil is etched, which results in a rough texture on the treated side. The etched areas act as lithium cages as the binding energy of lithium to the surface of etched Cu is much higher compared to that of the Cu-foil, helping to prevent the formation of dendrites from residual lithium during repeated charge and discharge cycles. Moreover, the formation of a stable solid-electrolyte interphase (SEI) layer is detected, confirming the creation of a lithophilic Cu-surface. The full cell battery of the etched-Cu current collector shows stable performance for 500 cycles with an average CE of ∼96%, indicating an exceptionally long cycling life, unlike that of conventional copper current collectors.