Robust crystallographic orientation and side reactions suppression with a scalable three-dimensional interface layer built by nitrogen-oxygen co-doped and hierarchical porous hollow carbon nanofibers for highly stable Zn anodes

Inhibiting dendrite formation, hydrogen evolution, and anode corrosion is essential for durable aqueous Zn-ion batteries (AZIBs). Herein, we fabricated multifunctional hollow carbon nanofibers (HCNFs), which are employed as a shielding layer for the Zn anode (Zn@HCNF). The synergistic effect of N, O co-doping, which introduces zincophilic sites, and the unique 3D hierarchical porous architecture of the HCNFs coating, which provides hollow channels for low-tortuosity diffusion, results in facilitated ion transport, reduced interfacial impedance, and thus, remarkably improved reaction kinetics. Concurrently, the coating provides a uniform deposition space for Zn²⁺, inducing its crystallographic orientation toward the (002) crystal plane (with the texture coefficient increasing from 0.95 to 2.23 after 50 h of cycling). Its prominent hydrophobicity (with the electrode contact angle increasing from 76° to 135°) further suppresses hydrogen evolution and corrosion by blocking direct exposure of metallic zinc to reactive water molecules. Consequently, the Zn@HCNF symmetric cells exhibit a prolonged cycling lifespan of over 1500 h under an areal capacity of 2.5 mAh cm⁻², and over 1200 h at an ultrahigh current density of 20 mA cm⁻², outperforming most existing analogous 3D porous coated zinc anodes. The HCNF coating effectively tackles the key anode challenges, offering a promising strategy for advanced AZIBs.