Dihydrophenazine Derived Pd ₆ L ₁₂ Cage: Self‐Assembly, Polyradical Cations, and Lithium Battery Cathode Application

Abstract In this study, we present the self‐assembly of a dihydrophenazine‐based Pd 6 L 12 ‐type coordination cage 1 showing excellent redox activity and demonstrate the use as the cathode for lithium batteries. The structure of cage 1 was confirmed by single‐crystal X‐ray diffraction analysis. The excellent reversible redox performance of 1 and its electrochromic properties induced by radical species were systematically characterized using in situ UV–vis–NIR and EPR spectroelectrochemistry. Notably, a highly stable radical cationic species 1 12•+ , containing 12 radical cations, was successfully obtained through the chemical oxidation of 1 , and its single‐crystal structure was resolved. The excellent redox properties of 1 enable its application as a cathode material for lithium batteries. The 1 |Li cell exhibited good cycling stability, nearly 100% coulombic efficiency, and an initial discharge capacity of 84 mAh g⁻¹ within a voltage range of 2.5–4.0 V. Furthermore, in situ 2D EPR experiments on lithium batteries visually revealed the excellent cycling stability of the 1 ‐based cathode material and its reversible two‐step electron transfer process. This study provides important insights into the design, synthesis, and properties of functionalized redox‐active coordination cages, offering a reference for their application in energy storage and functional materials research.