A LiF-Pie-Structured Interphase for Silicon Anodes

• A novel hierarchical solid electrolyte interface (SEI) structure is developed, featuring a lithium fluoride (LiF)-rich inner layer and a silane-based cross-linked matrix. • A comprehensive suite of advanced characterization techniques provides multi-scale insights into the structural and chemical composition of the LiF-Pie SEI. • The proposed SEI design significantly enhances cycling stability, achieving a capacity retention of LiCoO2||Si increase from 49.6% to 88.9% after 300 cycles at a current density of 100 mA g−1. • The LiF-Pie SEI offers a desirable interfacial design principle with enhanced electrochemical and mechanical stability, crucial for sustaining Si anode functionality and advancing practical applications.