Hydrogen‐Bonded Organic Frameworks (HOFs) Composite Polymer Electrolyte Enables the Stable Long‐Term Cycling of Lithium Metal Batteries with High‐Voltage Cathode

S cm⁻¹ at 30 °C), a favorable lithium-ion transference number (0.71), and an extended electrochemical stability window (5.4 V). Additionally, lithium metal batteries utilizing this electrolyte achieved outstanding performance, with LFP| HCPG@SPE| Li cells retaining 98% capacity after 1000 cycles at 5 C, and NCM811| HCPG@SPE| Li cells demonstrating stable cycling for 700 cycles at 1 C. The results suggest that the HOF-based composite electrolyte holds significant promise for next-generation high-performance solid-state lithium batteries.