Synthesis of SiO_x Powder Using DC Arc Plasma

摘要

SiO_x was prepared by DC arc plasma and applied to the anode material of lithium ion batteries. A pellet of a mixture of Si and SiO_2 was used as the raw material. The ratios of the silicon and silicon dioxide (SiO_2) mixtures were varied by controlling the Si-SiO_2 molar ratio (Si-SiO_2 = 1～4). Hydrogen gas was used as the reduction atmosphere in the chamber. The prepared SiO_x was collected on the chamber wall. The obtained SiO_x was characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). XRD and TEM showed that the phase composition of the prepared particles was composed of amorphous SiO_x and crystalline Si. The prepared SiO_x showed wire and spherical morphology. XPS indicated the bonding state and 'x' value of the prepared SiO_x, which was close to one. The result of prepared SiO_x is discussed from thermodynamic equilibrium calculations. The electrochemical behavior of the silicon monoxide anode was investigated.