Crystal Transformation Strategy in Hydrogen‐Bonded Organic Framework Solid‐State Electrolyte for Stable Zinc‐Ion Batteries

Abstract Solid‐state zinc ion batteries (ZIBs) hold great potential for sustainable and high‐safety reserves. However, the advancement of solid‐state ZIBs is constrained by the shortage of reasonable solid‐state electrolytes (SSE) with abundant hopping sites, effective hydrogen evolution reaction (HER) inhibition, and favorable interfacial compatibility. Herein, the hydrogen‐bonded organic framework (HOF) CAM‐Ag with Zn 2+ hopping sites is developed as SSE for ZIBs. Taking advantage of the short‐distance Zn 2+ conduction pathways by crystal transformation through incorporating the Ag−N coordinate bonds, CAM‐Ag SSE achieves a significant ionic conductivity of 1.14 × 10 −4 S cm −1 at room temperature and superior Zn 2+ transference number of 0.72. An abundant hydrogen bonds network effectively inhibits the initiation of HER and the subsequent generation of by‐products. Moreover, the rapid Zn 2+ conduction kinetics facilitated the inhibition of dendrite growth, promoting the uniform Zn 2+ distribution. CAM‐Ag SSE displays an extensive electrochemical stability range of 0–2.66 V and remarkable electrochemical compatibility, enabling stable Zn 2+ plating/stripping for ≈1000 h at 1 mA cm −2 . Consequently, CAM‐Ag SSE‐based solid‐state ZIBs achieve a specific capacity of 315 mAh g −1 with only 1.5% decrease in capacitance after 24 h. The proposed HOF‐based SSE displays a potential pathway for advancing stable and high‐performance solid‐state ZIBs.