Pre‐Fluorination Interface Engineering of Silicon‐Based Anode for Durable Lithium‐Ion Batteries
Xueyi Nie, Guanglu Wei, Chenwu Zhang, Fengjun Ji, Tiansheng Bai, Weihao Xia, Jingchuan Gao, Yu Wang, Wei Zhai, Jingyu Lu, Deping Li, Lijie Ci
Abstract
Abstract Silicon (Si) anodes are considered promising candidates for next‐generation lithium‐ion batteries (LIBs) due to their high theoretical capacity (≈10 times that of graphite). However, the substantial volume expansion during cycling (>300%) results in the degradation of the solid electrolyte interphase (SEI) and pulverization of Si anodes. Herein, an AlF 3 coating layer is introduced onto commercial Si‐C composites (Si‐C@AF‐x) as an artificial SEI layer, which effectively modulates the interfacial environment with higher kinetics and stability. The Si‐C@AF‐1 anode achieves excellent cycling stability (capacity of 916.0 mA h g −1 after 100 cycles at 0.5 C and retention of 91.6%) and rate capability (549.7 mA h g −1 at 3.0 C). Even under extreme temperatures, the AlF 3 coating layer can still support the fast and stable operation of the Si‐C@AF‐1 electrode, and the Si‐C@AF‐1||NCM811 full cell delivers 85.2% capacity retention after 100 cycles at 0.5 C. This work proves the effectiveness of designing a robust artificial SEI for enhancing the interfacial kinetics and stability, which also fits well with the commercial‐scale production of electrode materials, thereby highlighting its strong commercialization potential for high‐durability LIBs.