Decoupling Lithiophilicity and Ion Transport via Dual‐Gradient 3D Current Collectors for Stable Lithium Metal Anodes

ABSTRACT The application of lithium‐metal anodes (LMAs) is hindered by uncontrollable dendrite growth and severe volume fluctuations. Although 3D current collectors can alleviate these issues, top‐surface Li accumulation on lithiophobic frameworks and the trade‐off between lithiophilicity and ion‐transport kinetics in conventional designs remain challenges. We report a dual‐gradient 3D current collector (SCA) fabricated via ion‐beam sputtering that decouples and coordinates these two factors. The Ag‐rich top layer features an ultralow Li + migration barrier to ensure rapid ion transport, while the Sn‐rich bottom layer offers strong lithiophilicity to guide Li nucleation. DFT calculations on both pristine metals and lithiated alloy phases show that this thermodynamic–kinetic decoupling is preserved after alloy formation, confirming the robustness of the guiding function during cycling. Combined with Li + concentration field simulations and morphological analyses, the dual‐gradient architecture enables stable bottom‐up Li deposition with efficient utilization of the 3D framework. Li@SCA symmetric cells achieve an ultralong lifespan of 2620 h, and Li@SCA||LFP full cells retain 72.1% capacity after 680 cycles. The dual‐gradient structure also exhibits excellent low‐temperature performance, delivering 119 mAh g −1 at −60°C and maintaining 77.8% capacity retention after 120 cycles at −20°C.