A sandwich-like Si/SiC/nanographite sheet as a high performance anode for lithium-ion batteries

Abstract

Silicon/carbon (Si/C) nanocomposite anodes have attracted great interest for their use in lithium-ion batteries (LIBs). However, Si nanoparticles are difficult to stabilize on a carbon surface. Herein, we solve this stabilization problem by designing a Si/silicon carbide/nanographite sheet (Si/SiC/NanoG) nanocomposite. The Si/SiC/NanoG nanocomposite is synthesized by the magnesium thermal reduction of a mixture of silica (SiO₂) nanoparticles and NanoG at low temperature, which results in a sandwich-like structure in which the middle SiC layer serves as a linker to stabilize the Si nanoparticles on the surface of NanoGs. Electrochemical characterization shows that the Si/SiC/NanoG nanocomposite anode exhibits outstanding electrochemical performance (an initial reversible capacity of 1135.4 mA h g⁻¹ and 80.4% capacity retention after 100 cycles at 100 mA g⁻¹). This high capacity retention is due to the strong connection between Si and NanoG through the interfacial SiC layer, which buffers the volume changes during the Li–Si alloying–dealloying process. This research will contribute to the design of advanced Si/C anode materials of LIBs.