Constructing an ion-oriented channel on a zinc electrode through surface engineering

The inherent shortcomings of a zinc anode in aqueous zinc-ion batteries (ZIBs) such as zinc dendrites and side reactions severely limit their practical application. Herein, to address these issues, an ion-oriented transport channel constructed by graphdiyne (GDY) nanowalls is designed and grown in situ on the surface of a zinc electrode. The vertically stacked GDY nanowalls with a unique hierarchical porous structure and mechanical properties form a nanomesh-like interface on the zinc electrode, acting as an ion-oriented channel, which can efficiently confine the segmented growth of zinc metal in microscopic regions of hundreds of nanometers. In those microscopic regions, the uniform domain current density is effortlessly maintained compared with a large surface area, thereby inhibiting zinc dendrites effectively. Besides, due to the presence of the ion-oriented channel, the modified zinc anode demonstrates long-term stable zinc plating/stripping performance for more than 600 h at 1 mAh cm⁻² in an aqueous electrolyte. In addition, full-cells coupled with MnO₂ show high specific capacity and power density, as well as excellent cycling stability with a capacity retention of 82% after 5000 cycles at 1 A g⁻¹. This work provides a feasible and accessible surface engineering approach to modify the electrode interface for confined and dendrite-free zinc deposition in aqueous ZIBs.