Vertically Fluorinated Graphene Encapsulated SiOx Anode for Enhanced Li+ Transport and Interfacial Stability in High‐Energy‐Density Lithium Batteries

Abstract Achieving high energy density has always been the goal of lithium‐ion batteries (LIBs). SiO x has emerged as a compelling candidate for use as a negative electrode material due to its remarkable capacity. However, the huge volume expansion and the unstable electrode interface during (de)lithiation, hinder its further development. Herein, we report a facile strategy for the synthesis of surface fluorinated SiO x (SiO x @vG−F), and investigate their influences on battery performance. Systematic experiments investigations indicate that the reaction between Li + and fluorine groups promotes the in situ formation of stable LiF‐rich solid electrolyte interface (SEI) on the surface of SiO x @vG−F anode, which effectively suppresses the pulverization of microsized SiO x particles during the charge and discharge cycle. As a result, the SiO x @vG−F enabled a higher capacity retention of 86.4 % over 200 cycles at 1.0 C in the SiO x @vG−F||LiNi 0.8 Co 0.1 Mn 0.1 O 2 full cell. This approach will provide insights for the advancement of alternative electrode materials in diverse energy conversion and storage systems.