Enhanced Zn (101)‐Textured Dense Deposition Enabled by a Functional Separator for Ultrastable Zinc Metal Anodes

ABSTRACT In aqueous zinc‐ion batteries, zinc deposition on the Zn (002) crystallographic plane is constrained by sluggish kinetics and limited active sites. To address this limitation, we construct a cyano‐functionalized carbon nitride layer (CN─C 3 N 4 @GF) on a glass fiber (GF) separator via chemical vapor deposition. This functional layer combines sufficient mechanical robustness to suppress dendrite penetration with regulated nanoporous channels that promote rapid Zn 2+ transport. The surface‐enriched cyano groups (─C≡N), serving as strong electron‐donating coordination sites, form high‐binding‐energy coordination interactions with Zn 2+ , thereby modulating the solvation structure and lowering the desolvation energy. More importantly, interfacial CN─C 3 N 4 preferentially adsorbs onto the Zn(002) plane, thereby regulating the crystallographic growth behavior and guiding Zn deposition along the kinetically favorable Zn (101) plane. This preferentially regulated growth suppresses dendrite formation and produces a dense, highly textured zinc deposition layer. As a result, Zn||Zn symmetric cells using the CN─C 3 N 4 @GF separator operate stably for 2380 h at 0.5 mA cm −2 /0.5 mAh cm −2 and for 1000 h at 5 mA cm −2 . Moreover, Zn||MnO 2 full cells retain a high specific capacity of 154.9 mAh g −1 after 3000 cycles at 5 A g −1 , demonstrating excellent high‐rate cycling stability. This work presents an interfacial engineering strategy for highly reversible zinc metal anodes.