Synergistic Ion‐ and Electron‐Conductive Ca–Al‐Layered Double Hydroxide/Graphitized Carbon Black Hybrid Layer for Ultra‐Stable Zinc Metal Anodes

Achieving reversible zinc anodes is crucial for aqueous zinc‐ion batteries (AZIBs), but dendrite growth and side reactions severely limit their cycling life. Constructing a stable protective coating is an effective strategy to improve anode stability. Herein, a composite of graphitized carbon black and calcium–aluminum layered double hydroxide (denoted as GCB/LDH) is fabricated as an ex‐situ‐formed protective layer over the Zn anode. This GCB/LDH coating exhibits a hierarchical porous structure, in which the ion‐conductive LDH framework homogenizes Zn 2+ flux and suppresses dendrite growth, while the conductive GCB network uniformizes the electric field and mitigates water‐induced side reactions. Combined experimental and theoretical analyses reveal that the GCB/LDH layer promotes dense zinc nucleation and guides uniform Zn deposition by modulating ion transport and interfacial interactions. The symmetric cell with GCB/LDH@Zn achieves stable plating/stripping over 2700 h at 1 mA cm −2 . The MnO 2 /CNT// GCB/LDH@Zn full battery retains 88.24% capacity after 6200 cycles at 1 A g −1 . This work offers a promising interfacial engineering strategy for highly stable Zn anodes in AZIBs.