Strain‐Ligand‐Coupled D‐Band Regulation in LiZnNiCu Quaternary Alloy Interfaces for Reversible Lithium Electrodeposition

ABSTRACT Anode‐free lithium metal batteries (AFLMBs) offer a route to high cell‐level energy density by eliminating excess Li metal, but their reversibility is limited by heterogeneous Li nucleation, sluggish Li‐adatom migration, and unstable solid electrolyte interphase (SEI) formation on Cu current collectors. Here, a strain‐ligand‐coupled, d‐band‐regulated LiZnNiCu quaternary alloy interface is developed on Cu foil for reversible Li electrodeposition. DFT calculations indicate that built‐in tensile strain shifts the d‐band center of surface metal sites toward the Fermi level, whereas local Li‐derived ligand effects redistribute interfacial charge. This coupled regulation strengthens Li anchoring, lowers the Li‐adatom diffusion barrier, and promotes 3D instantaneous nucleation with compact Li deposition. In parallel, positively charged surface sites enhance anion adsorption, facilitating the formation of an inorganic‐rich, mechanically robust SEI that mitigates dendritic growth and inactive Li accumulation. Consequently, LiZnNiCu@Cu sustains Li plating/stripping for over 800 cycles with an average Coulombic efficiency of 99.2% under 1 mA cm −2 /1 mAh cm −2 , and delivers an Aurbach Coulombic efficiency of 99.75%. With Li 3 N‐assisted Li compensation, NCM‐Ni94‐based anode‐free full cells retain 89.9% capacity after 120 cycles and achieve 405.4 Wh kg −1 under lean‐electrolyte conditions. This work identifies strain‐ligand‐coupled d‐band regulation as a viable interface‐design strategy for high‐energy AFLMBs.