Anion‐Interactive Anode Interfaces for Stable Anode‐Free Lithium Metal Batteries

Anode‐free lithium metal batteries (AFLMBs) offer high energy density but face challenges of uncontrolled lithium nucleation, unstable solid‐electrolyte interphase (SEI) formation, and irreversible lithium loss. This study presents a nanofabrication‐guided interfacial engineering strategy using a 3D nanotubular copper (Cu) current collector conformally coated with an ultrathin (∼10 nm) Ti 3 C 2 T x MXene nanosheet. This multifunctional, anion‐interactive interface induces uniform lithium nucleation and enhances PF 6 − adsorption, directing the formation of a conformal, LiF‐rich inorganic SEI throughout the 3D nanoarchitecture. Ex situ X‐ray photoelectron spectroscopy (XPS), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), and transmission electron microscopy (TEM) analyses reveal that preferential LiF nanoparticles form along the MXene layer, improving interfacial homogeneity and SEI robustness. Under lean‐electrolyte conditions, anode‐free full‐cell tests (coin‐cell type, Li‐free MXene‐NT Cu||NCM811) exhibit superior cycling performance, delivering 78.1 mAh g −1 at the 125 cycle with 99.06% Coulombic efficiency, whereas the bare Cu counterpart achieves only 44.9 mAh g −1 and 95.01%, respectively. These results highlight the importance of rational nanomaterial design and nanoscale interfacial modulation in enabling stable, high‐performance AFLMBs.