Elucidating the role of lithiophobic Ni in porous CuNi for improving Li plating/stripping behaviors and solid electrolyte interphase formation for Li-metal batteries

Achieving uniform deposition of metallic Li and stabilizing solid electrolyte interphase (SEI) are essential for addressing the formation of dendritic Li and continuous depletion of electrolyte in Li-metal batteries (LMBs). Porous current collectors could ameliorate the problem of Li dendrites, but are unsatisfactory for fully addressing the above two issues. Herein, porous CuNi solid solutions (P-Cu100-xNix, 100-x Ni x , x = 5, 10, 15, and 20) were fabricated using vapor phase alloying followed by vapor phase dealloying, as current collectors for LMBs. The impact of Ni incorporation on Li plating/stripping behaviors and SEI formation was investigated using in-situ spectroscopy techniques, ex-situ characterizations, and density functional theory calculations. As benchmarked with P-Cu, the Ni introduction significantly improves the Li plating/stripping processes, alters the generation of organic components in SEI with additional inorganic components, releases less gases, and thereby enhances the electrochemical performance of P-Cu100-xNix. 100-x Ni x . Our findings provide a new strategy to address the main issues in LMBs using porous solid solution alloys as the current collector.