Active Oxygenated Group‐Rich Polymer Electrolyte Synchronizing Bilateral Interfacial Stabilization and Accelerated Kinetics for High‐Performance Solid‐State Li–O ₂ Batteries

ABSTRACT The vision of commercializing high‐energy‐density solid‐state lithium–oxygen batteries (SSLOBs) is hindered by poor interfacial compatibility and sluggish cathodic reaction kinetics resulting from the solid–solid contact on both sides of the solid‐state electrolyte. Herein, an innovative polymerized glycidyl methacrylate (PGM) electrolyte with abundant active oxygenated groups (AOGs), that is, C═O and C─O─C, is demonstrated to synchronize bilateral interfacial compatibility and accelerated cathodic reaction kinetics for high‐performance SSLOBs. Notably, the PGM modulates the Li + solvation structure by expelling partial solvent molecules, inducing the formation of a dense oxide‐rich solid electrolyte interphase on the Li metal anode, which suppresses dendrite growth. Theoretical calculations further elucidate that the AOGs stabilize the lithium‐oxygen intermediates (e.g., LiO 2 , Li 2 O 2 ) and lower the energy barrier for Li 2 O 2 decomposition, thereby accelerating oxygen reaction kinetics. Consequently, the PGM‐based LOBs (PGM‐LOBs) exhibit a high capacity of 13 076 mAh g −1 at 200 mA g −1 , a low overpotential of 0.56 V, and a long life of 150 cycles (1500 h). In ambient air, PGM‐LOBs maintain stable cycling for 400 h and deliver a discharge capacity of 19 044 mAh g −1 at 200 mA g −1 . This study demonstrates a feasible AOG‐rich polymer electrolyte design strategy to simultaneously improve interfacial compatibility and oxygen redox kinetics for advanced SSLOBs.