3D-printing of patterned Zn anodes toward dendrite-free zinc ion batteries

3D Zn anodes, boasting a high specific surface area to reduce the local current density, have emerged as promising electrodes for dendrite-free Zn-ion batteries (ZIBs). Despite their potential, the impact of diverse topological structures of Zn anodes on Zn deposition behavior within these electrodes remains poorly understood. To elucidate this relationship, this study employed direct ink writing technology to 3D print Zn anodes with four distinct topological configurations. The 3D array Zn anode featured with an angle between two connected printing strips of 180° (3DP-180) stood out for the fewest electrode joint points among these four anodes, migrating the tip effect and facilitating uniform electric field/ion distribution, which in turn promoted even Zn deposition and effectively suppressed Zn dendrites. The 3DP-180 array anode demonstrated a notably low nucleation overpotential of 27.2 mV, indicating a superior capacity for Zn nucleation and uniform Zn deposition. Moreover, symmetrical cell assembled with 3DP-180 array anode achieved 800 hours of continuous cycling without degradation at a current density of 1 mA cm⁻² and a capacity of 0.5 mAh cm⁻². These results highlight the improved cycle lifespan afforded by the superior structural design of Zn anodes, offering valuable insights to inform the development of next-generation durable and safe ZIBs.