Silicon nanoparticles synthesized using double tube reactor and inductive coupled plasma

Abstract

Silicon (Si) nanoparticles were synthesized using a double tube reactor and inductive coupled plasma (ICP), and their microstructures with various process conditions were investigated in terms of plasma density and residence time of reactive gas in the plasma zone. Homogeneous amorphous or single crystalline Si nanoparticles were synthesized depending on applied power to ICP coil. The SiH4 flow rate mainly determined the particle size. Average particle sizes of the synthesized Si nanoparticles were 14–34 nm, and the maximum production rate was as high as 1000 mg h−1. The purity of synthesized Si nanoparticles was higher than 99.99%. When Si nanoparticles were applied as an active material in the anode of a Li-ion battery (LIB), the high first reversible capacities of 2540 (initial coulombic efficiency (ICE) = 61.4%) and 1358 mAh g−1 (ICE = 62.5%) for crystalline and amorphous Si nanoparticles were attained, respectively. However, capacity fadings were detected in both nanoparticles, and capacity retentions at 100th cycle were only 17.1% and 34.8% for crystalline and amorphous Si nanoparticles.