High‐Precision 3D Copper Substrate with Tunable Pore Sizes for Zinc Dendrite Suppression

Aqueous zinc‐ion batteries (AZIBs) feature low cost, high safety, and environmental friendliness, yet zinc dendrite growth severely limits their cycling stability and practical application. Herein, a high‐precision honeycomb‐structured copper substrate with tunable pore sizes is reported for Zn dendrite suppression, and this is the first realization of a highly zincophilic pure Cu host fabricated by 3D printing. The constructed Zn@3D Cu anodes via electroplating significantly improve the utilization rate of metallic Zn. Compared with planar 2D Zn and Zn@2D Cu electrodes, the Zn@3D Cu anode with an optimal pore size of 225 µm effectively homogenizes the electric field distribution and guides uniform Zn deposition without dendrite growth, as confirmed by electric field simulations and in situ microscopic observations of Zn electroplating. Consequently, the half‐cell with 3D Cu exhibits a superior Coulombic efficiency of 99.77% after 1000 cycles, while the Zn symmetric cell with highly ordered Zn@3D Cu anode demonstrates an ultra‐long cycling life of 3200 h at 1 mA cm −2 (0.5 mAh cm −2 ). Over 480 h of stable cycling is further achieved with Zn@3D Cu at a high depth of discharge of 50%. Moreover, full cells constructed by the 3D‐printed Zn@Cu anode and conventional vanadium oxide cathode exhibit remarkable electrochemical performances.