Single‐Crystalline Hydrogen‐Bonded Organic Frameworks as Solid Electrolytes for Lithium Metal Batteries

Solid‐state lithium metal batteries represent a pivotal advancement in energy storage technology, prized for their superior safety and high‐energy density. The combination of high ionic conductivity, high‐voltage stability, and lithium dendrite suppression has prompted the investigation of new solid‐state electrolyte (SSE) systems. In this work, a SSE is reported based on a 4,4′‐diamino‐2,2′‐stilbenedisulfonic acid constructed hydrogen‐bonded organic framework (DS‐HOF). The DS‐HOF single crystal, leveraging its abundant hydrogen‐bonding sites and polar groups, demonstrates an ionic conductivity of 1.65 mS cm −1 , a lithium transference number of 0.42, and a wide electrochemical stability window of 5.5 V. The assembled lithium symmetric battery achieved stable cycling for over 1,300 h and uniform deposition, mainly due to the uniform transport of Li + through aligned Li + transport channels in DS‐HOF and the buffering of structural changes during lithium deposition by flexible hydrogen‐bonding networks. Furthermore, full cells assembled with LiFePO 4 cathodes retain 88% of their capacity after 200 cycles at 0.5 C, coupled with a high Coulombic efficiency of 99.92%. The electrolyte also demonstrates compatibility with a high‐voltage NCM811 cathode, supporting stable cycling for 50 cycles without short‐circuiting. These findings collectively underscore the significant potential of HOF‐based materials as an emerging platform for next‐generation SSEs.