High purity silicon whiskers extraction from silica by novel simple technology

Abstract Si dendrites and whiskers were obtained by interaction of gaseous AlF with SiO2 during transport chemical reaction, using Al, AlF3 and SiO2 as starting materials. The dependence of the reaction yield on such technological parameters as temperature, transport gas flow-rate, reactor chamber pressure and molar ratio of the initial compounds was determined. The thermodynamic simulation of processes in reaction chamber was performed by the HSC Chemistry program using HSC-Reaction and HSC-Gibbs modules. Reaction products were characterized by X-ray powder diffraction and scanning electron microscopy. Obtained Si crystallizes as dendrites and whiskers with diameters varying in 100 nm – 24 µm range. The obtained data shows perspectives for adaptation of the proposed technology for production of Si anode material; moreover, the mechanism of proposed synthesis method can be improved for one-stage production of Si/C composite by using CO2 in process as C source as well as development of a novel CO2 utilization technology.