In Situ Artificial Hybrid SEI Layer Enabled High‐Performance Prelithiated SiOx Anode for Lithium‐Ion Batteries

Abstract Considered the promising anode material for next‐generation high‐energy lithium‐ion batteries, SiO x has been slow to commercialize due to its low initial Coulombic efficiency (ICE) and unstable solid electrolyte interface (SEI) layer, which leads to reduced full‐cell energy density, short cycling lives, and poor rate performance. Herein, a novel strategy is proposed to in situ construct an artificial hybrid SEI layer consisting of LiF and Li 3 Sb on a prelithiated SiO x anode via spontaneous chemical reaction with SbF 3 . In addition to the increasing ICE (94.5%), the preformed artificial SEI layer with long‐term cycle stability and enhanced Li + transport capability enables a remarkable improvement in capacity retention and rate capability for modified SiO x . Furthermore, the full cell using Li(Ni 0.8 Co 0.1 Mn 0.1 )O 2 and a pre‐treated anode exhibits high ICE (86.0%) and capacity retention (86.6%) after 100 cycles at 0.5 C. This study provides a fresh insight into how to obtain stable interface on a prelithiated SiO x anode for high energy and long lifespan lithium‐ion batteries.