Ligand-engineered Ag nanoclusters-modified copper current collector for anode-free lithium metal battery

Anode-free lithium metal batteries (AFLMBs) exhibit significant potential for next-generation high-energy-density storage due to their inherently high energy density, low manufacturing cost and safety. However, non-uniform lithium nucleation and growth lead to the formation of lithium dendrites. These dendrites fracture readily during repeated plating/stripping cycles, transforming into electrochemically inert 'dead lithium' while mechanically disrupting the fragile solid electrolyte interface (SEI) layer and causing irreversible consumption of active lithium. Herein, a novel current collector is designed by decorating Cu with Ag nanoclusters bearing sulfur-containing ligands. The ligands, along with TFSI^-decomposition, may contribute to the formation of a sulfur-rich SEI, while Ag nanoclusters provide lithiophilic nucleation sites for reversible lithium cycling. This design enables improved AFLMBs. Based on the design, the LiFePO₄||Cu-Ag NCs-2 anode-free battery demonstrates an average coulombic efficiency of above 99.7% over 100 cycles at 1 C. Also, a 1.2 Ah anode-free pouch cell was constructed with 275 Wh kg^-1.