Bicontinuous Zinc Monoliths with a Protective Coating for Practical Zinc-Powder Anodes

Zinc powder (ZnP) emerges as a competitive anode material for aqueous zinc-ion batteries (AZIBs) due to its scalable processability, and precise areal capacity control. However, ZnP anodes suffer from critical electrical failure due to exacerbated electrolyte corrosion, unstable point-contact networks, and strain-induced isolation. Herein, a bicontinuous monolithic ZnP anode with a protective coating is developed to ensure stable and robust electron transport. The continuous metallurgical bonding replaces fragile point contacts to ensure unbroken electron conduction highways, while the continuous pore channels accommodate volumetric strain and homogenize Zn²⁺ flux. A metallic bismuth layer is coated on the monolithic ZnP anode surface to suppress parasitic reactions and induce Zn (002) deposition. As a result, the symmetric cells sustain 4680 h at 1 mA cm^-2/1 mAh cm^-2 and 700 h at 10 mA cm^-2/5 mAh cm^-2. When paired with a high-loading NaV₃O₈.1.5H₂O cathode, the full cell delivers 4.2 mAh cm^-2 initial capacity with 2.5 mAh cm^-2 capacity retention after 1200 cycles. This work addresses the electrochemical failure issues of ZnP anodes and provides new insights into the practical implementation of AZIBs.