Commonly used batch reactors for nanomaterial synthesis can be difficult to scale since rapid particle nucleation and growth require efficient mixing to produce monodisperse particle size distributions (PSD). Monodisperse particles can be synthesized through efficiently mixing the reactants in the liquid phase using a jet-mixing reactor. Using common synthesis precursors and concentrations, the jet-mixing reactor produces silver nanoparticles with a diameter of 5 ± 2 nm, as characterized by TEM, and a monomodal surface plasmon resonance (SPR) in the UV-vis spectrum. In comparison, a batch synthesis using the same concentrations of reactants produces nanoparticles with a diameter of 9 ± 4 nm and a bimodal SPR, indicating that jet-mixing produces a more monodisperse particle size distribution than batch synthesis. For the jet-mixing synthesis, the concentration of the capping agent can be reduced to a value of 0.05 mM while retaining a narrow full-width of half-maximum (FWHM) of the SPR spectrum. Interestingly, decreasing the capping agent quantity from the standard concentration of 0.2 mM to 0.05 mM decreases the FWHM of the SPR, corresponding to a more monodisperse PSD at lower capping agent concentration. This result is attributed to the increased stabilization at lower ion concentrations in the solution. For lowmore »
Controlled growth of silicon particles via plasma pulsing and their application as battery material
Abstract The use of silicon nanoparticles for lithium-ion batteries requires a precise control over both their average size and their size distribution. Particles larger than the generally accepted critical size of 150 nm fail during lithiation because of excessive swelling, while very small particles (<10 nm) inevitably lead to a poor first cycle coulombic efficiency because of their excessive specific surface area. Both mechanisms induce irreversible capacity losses and are detrimental to the anode functionality. In this manuscript we describe a novel approach for enhanced growth of nanoparticles to ∼20 nm using low-temperature flow-through plasma reactors via pulsing. Pulsing of the RF power leads to a significant increase in the average particle size, all while maintaining the particles well below the critical size for stable operation in a lithium-ion battery anode. A zero-dimensional aerosol plasma model is developed to provide insights into the dynamics of particle agglomeration and growth in the pulsed plasma reactor. The accelerated growth correlates with the shape of the particle size distribution in the afterglow, which is in turn controlled by parameters such as metastable density, gas and electron temperature. The accelerated agglomeration in each afterglow phase is followed by rapid sintering of the agglomerates into more »
- Award ID(s):
- 1940952
- Publication Date:
- NSF-PAR ID:
- 10322698
- Journal Name:
- Journal of Physics D: Applied Physics
- Volume:
- 55
- Issue:
- 9
- ISSN:
- 0022-3727
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Publisher's Version of Record
- https://doi.org/10.1088/1361-6463/ac3867
