Interface‐Targeting Carrier‐Catalytic Integrated Design Contributing to Lithium Dihalide‐Rich SEI toward High Interface Stability for Long‐Life Solid‐State Lithium‐Metal Batteries

Abstract The generation of solid electrolyte interphase (SEI) largely determines the comprehensive performance of all‐solid‐state batteries. Herein, a novel “carrier‐catalytic” integrated design is strategically exploited to in situ construct a stable LiF‐LiBr rich SEI by improving the electron transfer kinetics to accelerate the bond‐breaking dynamics. Specifically, the high electron transport capacity of Br‐TPOM skeleton increases the polarity of C−Br, thus promoting the generation of LiBr. Then, the enhancement of electron transfer kinetics further promotes the fracture of C−F from TFSI − to form LiF. Finally, the stable and homogeneous artificial‐SEI with enriched lithium dihalide is constructed through the in situ co‐growth mechanism of LiF and LiBr, which facilitatse the Li‐ion transport kinetics and regulates the lithium deposition behavior. Impressively, the PEO‐Br‐TPOM paired with LiFePO 4 delivers ultra‐long cycling stability over 1000 cycles with 81 % capacity retention at 1 C while the pouch cells possess 88 % superior capacity retention after 550 cycles with initial discharge capacity of 145 mAh g −1 at 0.2 C in the absence of external pressure. Even under stringent conditions, the practical pouch cells possess the practical capacity with stable electric quantities plateau in 30 cycles demonstrates its application potential in energy storage field.