1. Effect of hydrogen on the microstructure and electrochemical properties of Si nanoparticles synthesized by microwave plasma
- Author
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Jeong-Boon Koo, Joon-Soo Kim, Bo-Yun Jang, and Jeong-Eun Lee
- Subjects
Materials science ,Nanostructure ,Hydrogen ,Silicon ,Analytical chemistry ,chemistry.chemical_element ,Nanoparticle ,Atmospheric-pressure plasma ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,0104 chemical sciences ,Amorphous solid ,chemistry.chemical_compound ,chemistry ,Silicon tetrachloride ,General Materials Science ,0210 nano-technology - Abstract
We synthesized silicon (Si) nanoparticles using an atmospheric microwave plasma process, and investigated the effects of hydrogen (H2) injection on their microstructure during the synthesis. Two nozzles were applied to inject H2 (swirling and rectilinear H2). Our microstructural analysis indicated that the amount and method of H2 injection were critical for completion of the reaction from silicon tetrachloride (SiCl4) to Si, as well as to obtain highly crystalline Si nanoparticles. The swirling H2 was especially critical due to its formation of vortex flow, which allowed relatively long residence time of the H-ions in plasma. The Si nanoparticles synthesized by the atmospheric plasma process had core-shell structures that consisted of crystalline Si cores with amorphous SiOx shells of 5–15 nm thickness. We also investigated the feasibility of the synthesized Si nanoparticles as anode materials in a lithium-ion battery (LIB). For the core-shell structured Si nanoparticles, we obtained the first reversible capacity of 1204 mAhg−1, and a capacity retention of 82.2% at the 50th cycle. more...
- Published
- 2016
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