Synthesis of SiO_x/C Composite Nanosheets As High-Rate and Stable Anode Materials for Lithium-Ion Batteries

Nonstoichiometric silica suboxides (SiO_x) have been regularly investigated as hopeful anode materials for the substitutions of silicon. However, the inherently poor conductivity of SiO_x limits its promotion in industry. Herein, for the propose of enhanced conductivity and stability of SiO_x-based materials, a kind of multicomponent nanosheet (rGO@SiO_x@C) is designed and fabricated successfully. This progressive design consists of inner nanosheet substrate from reduced graphene oxide (rGO), an intermediate layer of SiO_x, and a nitrogen-doped nanoporous carbon (NNC) shell from the pyrolysis of poly­(vinylpyrrolidone). More importantly, the controllable pore structure is introduced into this two-dimensional nanostructure, accommodating volumetric change of SiO_x during the charging/discharging process. Benefiting from unique structural advantages, the as-prepared rGO@SiO_x@C nanosheets exhibit excellent electrochemical properties, such as high rate performance and stable long lifetime. We anticipate that this approach to enhance the conductivity and stability of SiO_x-based anode materials has potential applications for future sustainable development in lithium-ion batteries.