Spark erosion: a high production rate method for producing Bi_0.5Sb_1.5Te₃nanoparticles with enhanced thermoelectric performance

Abstract

We report a new 'spark erosion' technique for producing high-quality thermoelectric nanoparticles at a remarkably high rate and with enhanced thermoelectric properties. The technique was utilized to synthesize p-type Bi(0.5)Sb(1.5)Te(3) nanoparticles with a production rate as high as 135 g h(-1), using a relatively small laboratory apparatus and low energy consumption. The compacted nanocomposite samples made from these nanoparticles exhibit a well-defined, 20-50 nm size nanograin microstructure, and show an enhanced figure of merit, ZT, of 1.36 at 360 K. Such a technique is essential for providing inexpensive, oxidation-free nanoparticles which are required for the fabrication of high performance thermoelectric devices for power generation from waste heat, and for refrigeration.

Silicide Nanopowders as Low-Cost and High-Performance Thermoelectric Materials

“…40 The spark erosion process was originally invented by Berkowitz and Walter to produce micron-sized and amorphous powders of metals. 41 By tuning the process conditions, Nguyen et al have demonstrated the application of the spark erosion process in producing large quantity (>100 g scale) of metal and semiconductor nanoparticles.…”

“…41 By tuning the process conditions, Nguyen et al have demonstrated the application of the spark erosion process in producing large quantity (>100 g scale) of metal and semiconductor nanoparticles. 40 The basic idea and apparatus of the spark erosion process is shown in Fig. 6, which is a sketch of the spark erosion system.…”

“…Using this method, Nguyen et al 40 reported the synthesis of thermoelectric Bi 0.5 Sb 1.5 Te 3 nanoparticles with a production rate as high as 135 g/h using the relatively small laboratory apparatus and low energy consumption. The compacted nanocomposite samples made from these nanoparticles exhibit a well-defined, 20 to 50-nm size nanograin microstructure and show an enhanced figure of merit, ZT, of 1.36 at 360 K. This technique is very promising for producing inexpensive and oxidation-free nanoparticles for fabricating high-performance thermoelectric materials.…”

“…In addition, since the entire process was carried out in dielectric liquids (liquid Ar or N, Ref. 40), oxidation-free nanoparticles of Mg 2 (SiSn) can be readily synthesized using this approach. Therefore, this method could be a very promising route for producing a large quantity of high-quality thermoelectric silicide nanopowders.…”

Microstructure Analysis and Thermoelectric Properties of Melt-Spun Bi-Sb-Te Compounds

“…However, these technologies are still far from commercialization in terms of mass production. The continuous attempts to reduce grain size of the TE materials have been tried via high-energy ball milling [15,16], spark erosion [17], melt spinning (MS) [8,[18][19][20], and bottom-up chemical synthesis processes [21][22][23].…”