Hierarchical array hosts with concave spatial confinement and zincophilic seed mediated growth for dendrite-free Zn metal anode

Uneven distribution problems with Zn electrodeposition have emerged as a major obstacle to the development of Zn-ion batteries. A hierarchical array is proposed in this work to synthesize a three-dimensional Zn anode host, composed of Bi-loaded N-doped carbon triangular plates containing carbon nanotubes (Bi/NC-CNTs@CC), and uniform Zn electrodeposition has been achieved through a synergistic regulation strategy of concave spatial confinement and a “microchannel-filling” zincophilic seed mediated growth. The architecture of evenly arranged arrays contributes to homogenizing the surface electric field and reducing the interfacial polarization due to a geometrical confinement effect. The rationally distributed zincophilic Bi particles can further favor the preferential Zn nucleation, verified by both theoretical calculations and electrochemical measurements. The delicately constructed Bi/NC-CNTs@CC host exhibits a high Coulombic efficiency of 99.9 % over 1700 cycles in an asymmetric cell and elongates the Zn plating/stripping lifespan to 8000 h after pre-plating 6 mAh cm⁻² of Zn (Bi/NC-CNTs@CC-Zn) in a symmetric cell. Moreover, a full battery assembled by the Bi/NC-CNTs@CC-Zn anode and a MnO₂ cathode demonstrates a high specific capacity of 293.3 mAh g⁻¹ at 0.2 A g⁻¹ and a stable capacity retention of 87.1 % over 1000 cycles.