Refrigeration, air conditioning, and other cooling requirements in buildings, industry, and transportation sectors account for about 10 quads of U.S. primary energy consumption. Therefore, advanced technologies for space cooling in buildings and vehicles - as well as for refrigeration in residential, commercial, and industrial applications - that are more energy efficient, avoid net direct greenhouse gas emissions, reduce lifecycle costs, and can impact large markets are needed. Although current technologies are reaching their efficiency limits, thermoelectric (TE) materials can be used for cooling applications and have potential for significant improvements. Compared to traditional bulk phase TE materials, literature results suggest that nanometer-scale materials allow additional opportunities to improve the efficiency of TE materials. Aerogels are one type of nano-material that offers opportunities to increase the efficiency of TE materials by controlling particle size, particle composition and by reducing the thermal conductivity. Bismuth telluride (Bi 2Te 3) is the most studied TE material and our objective was to produce bismuth telluride aerogels with controlled microstructures and thermal conductivities to increase the TE figure of merit. Aspen Aerogels developed a novel synthesis method to prepare Bi 2Te 3 aerogels using the principles of colloidal chemistry and sol-gel chemistry. The reaction conditions were investigated and optimized so that gels could be obtained at low reaction temperatures. The gels were aged and dried using supercritical CO 2. The aerogels were characterized by BET, XRD, and SEM. The best aerogels were hot pressed and Seebeck coefficients were determined. The synthetic approach developed and the properties of the aerogels will be presented and compared with Bi 2Te 3 aerogels and materials prepared by other methods.
|Original language||English (US)|
|Title of host publication||Aerogels and Aerogel-Inspired Materials|
|Number of pages||6|
|State||Published - 2011|
|Event||2010 MRS Fall Meeting - Boston, MA, United States|
Duration: Nov 29 2010 → Dec 3 2010
|Name||Materials Research Society Symposium Proceedings|
|Other||2010 MRS Fall Meeting|
|Period||11/29/10 → 12/3/10|
Bibliographical noteFunding Information:
This work was supported by funding from Department of Energy, UAS, with Grant No. DE-SC0000948 (Aspen, Marlow) and the Center for Revolutionary Materials for Solid State Energy Conversion, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DESC0001054 (Wayne State).