A Bottom‐Up Zincophilic Gradient Design Enabling Long‐Cycle‐Life Zn Metal Anodes Under High Currents and Capacities

Abstract

ABSTRACT Metal anodes are crucial for achieving high‐energy‐density electrochemical energy storage. However, their practical performance under high current densities and high areal capacities is hampered by sluggish ion‐transport kinetics. This leads to concentration polarization, which promotes surface‐localized deposition and results in dendritic “top‐growth”, ultimately causing cell failure. In this work, we design a bottom‐up zincophilic gradient nanofiber mat as a host structure that reverses the deposition pathway. By thermodynamically driving metal ion nucleation preferentially at the host base, this strategy enables uniform bottom‐up deposition. As a result, the Zn anode achieves an average Coulombic efficiency of 98.9% for 1972 cycles at a high current density of 20 mA cm −2 . Symmetric cells with this host exhibit exceptional stability, operating for 1095 h at an ultrahigh current density of 50 mA cm −2 and 1328 h under a high areal capacity of 10 mAh cm −2 , substantially outperforming existing approaches. This work establishes gradient engineering as an effective and widely applicable strategy for enabling long‐life metal anodes.