Hydrogen‐Bond‐Rich Supramolecular Multiblock Copolymers Facilitate Rapid Zn 2+ Migration in Quasi‐Solid‐State Zinc‐Ion Batteries

Abstract Quasi‐solid electrolytes (QSEs) have emerged as a highly promising solution to address key challenges in zinc‐ion batteries (ZIBs). However, QSEs often rely on a significant amount of water (H 2 O) to facilitate rapid Zn 2+ migration, which can lead to undesirable side reactions at the Zn anode. Here, polyurethane supramolecular multiblock copolymers (PU‐EG+DMPA‐Zn) are synthesized from the perspective of polymer block structure design. Interactions between zinc salts and carboxyl groups in the chain extender enhance zinc salt solubility while disrupting the intrinsic hydrogen bond network within the polymer matrix. This modification extends the hydrogen bonds between the polymer and H 2 O, regulates the solvation structure of hydrated Zn 2+ , and suppresses side reactions at the anode interface. Additionally, the in situ forms gradient solid electrolyte interphase (SEI) during cycling provides a robust protective barrier that significantly enhances the reversibility of zinc anodes. The abundant hydrogen bond network endows the PU‐EG+DMPA‐Zn QSE with anti‐freezing properties, allowing the symmetric battery to maintain a stable plating/stripping process for 3000 h at −20 °C. The assembled Zn‐MnO 2 battery demonstrates a capacity retention rate of 93.8% after 2000 cycles at 2 A g −1 . Overall, this work provides a unique design strategy for developing high‐performance quasi‐solid electrolytes.