Refined Pore Structure Design and Surface Modification of 3D Porous Copper Achieving Highly Stable Dendrite‐Free Lithium‐Metal Anode

Abstract 3D porous copper is anticipated to serve as an ideal current collector for lithium‐metal anodes (LMAs) owing to its excellent conductivity, huge surface area, and cost‐effectiveness. However, most pertinent studies center around commercial copper foams, where their notable large pore size (150–400 µm) is identified as a primary inducement for dendrite formation and ultimate battery failure. Hence, ensuring the appropriate pore structure in 3D porous copper for achieving highly reversible lithium deposition/stripping process plays a pivotal role in stabilizing LMAs. Herein, the hydrogen bubble template method is employed to fabricate five distinct types of 3D porous copper. Among them, the one with an average surface pore diameter of 25.18 µm and the lowest probability of macropores distribution within the pore walls demonstrates optimal electrochemical performance. To further improve the inherent lithiophobicity of copper, Cu₂Se/Cu₂O heterostructure nanowires are loaded as kinetic enhanced nucleation sites. Benefiting from the synergistic effect of optimized pore structure and heterostructure nanowires, the Cu₂Se/Cu₂O@3D Cu composite current collector exhibits excellent dendrite‐free characteristics and outstanding electrochemical performance, showcasing an ultra‐long symmetrical‐cell lifespan of 3000 h at 1 mA cm⁻² and stability for 300 h even under 20 mA cm⁻².