Dual‐Sided Regulation of Lithium Deposition for High‐Energy‐Density Anode‐Less Lithium Metal Batteries

Anode‐less lithium (Li) metal batteries are the ultimate anode configuration for high‐energy‐density energy storage, yet their practical adoption is hindered by uncontrolled Li dendrite growth. Here, we present a dual‐sided regulation strategy that homogenizes Li deposition through simultaneous bottom‐up and top‐down control. At the current collector, an ultrathin platinum (Pt) layer leverages its lithiophilicity to stabilize nucleation and promote dense bottom growth. At the separator, an amorphous tantalum oxide (a‐TaO x ) ceramic layer exploits thermodynamic Li dewetting to suppress upward dendritic propagation, enforcing top‐down uniformity. This synergistic Pt/a‐TaO x dual‐interface design orchestrates Li deposition across the entire electrode, enabling stable cycling at high cathode areal capacities (4.78 mAh cm– 2 ) with 70% capacity retention after 110 cycles in an anode‐less configuration (N/P ratio = 0) and 80% after 187 cycles with pre‐lithiation (N/P ratio = 0.42). By transcending conventional bottom‐only protection, this work establishes a new framework for stabilizing Li deposition across the full thickness in high‐capacity anode‐less Li metal batteries.