Plasma-enhanced synthesis of nitrogen-doped silicon carbide nanopowders in a fluidized-bed reactor for lithium-ion battery anodes

Ultrafine silicon carbide (SiC) powders have garnered increasing attention mainly due to their vast potential for diverse applications. In this study, a plasma-enhanced fluidized bed reactor to crack hexamethyldisilane (HMDS) was effectively developed, thereby producing SiC/NC composites with diameters ranging from 10 to 20 nm. This method enabled large-scale and sustainable production of SiC/NC composites. Concurrently, nitrogen doping was finally achieved by introducing ammonia during the plasma process, which increased material defects and thus enhanced electrical conductivity. Moreover, the abundant hydrogen atoms in ammonia modulated the product properties, as evidenced by reduced particle size, enhanced crystallinity as well as decreased free-carbon content. The synthesized composites were applied as anodes in lithium-ion batteries, and their feasibility was confirmed through extensive testing. Notably, SiC-150 exhibited a discharge capacity of 413mAh g⁻¹ after 200 cycles at 0.1 A g⁻¹ and maintained a high specific capacity of 780mAh g⁻¹ even after 800 cycles at 0.5 A g⁻¹.