Constructing a Robust Solid–Electrolyte Interphase Layer via Chemical Prelithiation for High-Performance SiOx Anode

Being considered as a promising anode material for next-generation lithium-ion batteries, silicon oxide (SiO x ) suffers from low initial coulombic efficiency and unstable solid–electrolyte interphase (SEI), which hinder its commercial use. To address these issues, herein, an optimized chemical prelithiation method is developed using a molecularly engineered lithium–biphenyl-type complex, which facilitates improved prelithiation efficiency. More importantly, owing to the reaction between the prelithiation agent and sodium carboxymethyl cellulose binder, a stable artificial SEI layer with hard inorganic particles embedded in soft organic matrix can be preformed on the surface of the SiO x anode after prelithiation. The preformed SEI layer remains stable during long-term cycling, contributing to significant improvement of capacity retention (87.4%) over pristine SiO x (68.6%) after 100 cycles at 0.2 C. Through demonstrating a hitherto unknown interfacial constructing strategy for SiO x , this study provides a fresh perspective on realizing high-capacity Si-based anodes.