Synergistic Effects of Porous Dilute Multicomponent Cu-Based Solid Solutions in Li-Metal Batteries: In Situ and Theoretical Studies

Multicomponent alloys are promising current collectors for advanced Li-metal batteries (LMBs) to suppress Li dendrite growth yet suffer from complex interaction mechanisms, limited plasticity, and high costs. Optimizing component concentrations and understanding underlying mechanisms are crucial for the development of multicomponent alloys with enhanced electrochemical performance. Herein, a strategy is proposed for fabricating porous dilute multicomponent solid solutions with varying amounts of Ag, Al, Sn, and Sb in a Cu matrix (p-Cu_100-x(AgAlSnSb)_x, x = 0.4, 0.8, 2.0, 4.0) via vapor phase alloying followed by vapor phase dealloying. The synergistic effects of these dilute components enhance the mechanical properties and conductivity. Moreover, multiple in situ spectroscopies and theoretical calculations multiscalably reveal that porous architectures with abundant active sites in p-Cu_100-x(AgAlSnSb)_x create an adsorption energy gradient (-2.45 to -3.12 eV/Li) and inorganic-rich solid electrolyte interphase, which lowers the nucleation barrier and enables uniform Li deposition. More importantly, the optimized p-Cu_98.0(AgAlSnSb)_2.0 exhibits outstanding cycling stability (900 h) and elevated Coulombic efficiency (>90% for 184 cycles) in half cells and excellent performance in full cells with/without anode, as benchmarked with p-Cu. These findings underscore the potential of porous dilute multicomponent solid solution alloys for high-performance LMBs.