Preparation and electrochemical properties of NaF-Si-C-RGO hybrids

NaF and Si nanoparticles and graphite oxide (GO) flakes were dispersed in a thermosetting phenolic resin (PR) in an aqueous solution, followed by drying and carbonization at 700℃ to produce NaF-Si-C-RGO hybrids. The structure of the hybrids was characterized by SEM, TEM, TGA, XRD and Raman spectroscopy. The electrochemical properties of the hybrids as anode materials of lithium ion battery were investigated and showed better electrochemical performance, larger reversible capacity and higher capacity retention when compared with both NaF-Si-RGO and Si-C-RGO hybrids. The amorphous carbon coating on the Si nanoparticles, derived from the PR, restricts the formation of a solid-electrolyte interface film. The Na⁺ in NaF is inserted between the GO layers, which not only alleviates the re-stacking of graphene sheets, but also improves the dispersion of Si nanoparticles in RGO layers, leading to a high utilization of active materials. F-also inhibits the decomposition of the electrolyte and the generation of HF, which is favorable for the cycle stability of the electrode.