Highly crystalline hydrogen-bonded organic framework towards stable Zn metal anodes

Aqueous zinc-ion batteries (AZIBs) have aroused wide research enthusiasm due to their inherent safety, cost-effectiveness and sustainability advantages. However, the parasitic side reactions and rampant dendrite growth of Zn anodes seriously limit their application. In this work, a highly crystalline hydrogen-bonded organic framework (HOF-DAT) is prepared and evaluated as a protective coating for Zn anodes for the first time. The hydrogen-bonded networks as well as abundant polar groups prevent free water from contacting the Zn anode and assist Zn²⁺ de-solvation, thus significantly suppresses side reactions. Meanwhile, the ordered and stable porous structure could provide numerous channels, which ensure uniform and rapid transport/deposition for Zn²⁺, thus guiding Zn²⁺ flux and blocking interfacial corrosion. Benefiting from these advantages, the symmetric cell of HOF-DAT@Zn achieves stable plating/stripping of more than 780 h with lower polarization voltage. In addition, the HOF-DAT@Zn//NHVO full cell also delivers a higher initial discharge capacity of 355.5 mAh g^-1 at 1 A g^-1 and good reversible capacity of 248 mAh g^-1 after 200 cycles. This work offers insights for the design of HOF-based protective coating for AZIBs.