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

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 Zn2+ hopping sites is developed as SSE for ZIBs. Taking advantage of the short-distance Zn2+ conduction pathways by crystal transformation through incorporating the Ag-N coordinate bonds, CAM-Ag SSE achieves a significant ionic conductivity of 1.14 x 10-4 S cm-1 at room temperature and superior Zn2+ 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 Zn2+ conduction kinetics facilitated the inhibition of dendrite growth, promoting the uniform Zn2+ distribution. CAM-Ag SSE displays an extensive electrochemical stability range of 0-2.66 V and remarkable electrochemical compatibility, enabling stable Zn2+ plating/stripping for approximate to 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.