Dynamically Regulated Lithium Nucleation and Growth by Lithiophilic Seed Patterns With Laser-Induced Gradient Edge...

Lithium-metal anodes promise high energy density but suffer from non-uniform plating and dendrite growth. Here, we present a burr-free, gradient-edge lithiophilic seed patterning strategy on Ag-coated Cu current collectors via near-threshold Bessel-beam laser ablation. This study establishes two fundamental design rules for stable lithium electrodeposition. First, the gradient-edge topology significantly relaxes electric-field hotspots, directing uniform Li nucleation and preventing early-stage dendrite formation, as corroborated by finite-element simulations. Second, systematically controlling the areal coverage of lithiophilic micro-patterns modulates the local faradaic current density to precisely regulate Li nuclei density and size. This dynamic control sustains a smooth growth interface, revealing an optimal coverage window (∼45%-60%) that maximizes coulombic efficiency and minimizes interfacial impedance growth over cycling. At an optimized 45% coverage, nucleation overpotential drastically decreases to 30.9 mV (vs. 171.0 mV for bare Cu), maintaining compact Li deposits at 1.0 mAh cm^-2. When paired with LiFePO₄ cathodes in full cells, the patterned anodes exhibit superior rate capability and reduced voltage hysteresis (553 mV at 3 C). These findings highlight gradient-edge lithiophilic patterning and coverage optimization as a scalable route for durable, high-rate lithium-metal batteries.