A controllable and byproduct-free synthesis method of carbon-coated silicon nanoparticles by induction thermal plasma for lithium ion battery

Carbon coated silicon nanoparticle is regarded as a promising anode material for the next generation of lithium ion batteries, while the development of a cost-effective and environmental-friendly preparation method is still difficult and hinders the practical implementation. In this research, a controllable and byproduct-free synthesis method is proposed for the preparation of silicon nanoparticles with amorphous hydrogenated carbon coating. The current apparatus is operated based on the application of induction thermal plasma. Plasma properties are tunable by adjusting the ratio of tangential and radial gas flow rates (T/R), which compose the plasma sheath gas. Obtained results reveal the plasma shape is shrunk with higher T/R values, which will lead to a steeper temperature gradient and lower temperature distributions in reaction chamber. Consequently, the compositions and properties of synthesized particles can be modified with T/R values. The formation of SiC, which was an intractable issue before, can be vanished at higher tangential gas flow rates in current research and the capacity of silicon anode for batteries will be improved in predict. This research is significant for a deep understanding of plasma synthesis processing and design of batteries with excellent performance.