Journal of Materials Research

Articles

Bismuth telluride-based thermoelectric materials: Coatings as protection against thermal cycling effects

Witold Brostowa1 c1, Tea Datashvilia1, Haley E. Hagg Loblanda1, Travis Hilbiga1, Lisa Sua1, Carolina Vinadoa1 and John Whitea2

a1 Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science and Engineering and Department of Physics, University of North Texas, Denton, Texas 76207

a2 Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science and Engineering and Department of Physics, University of North Texas, Denton, Texas 76207; and Marlow Industries, Inc., Dallas, Texas 75238-1645

Abstract

Thermoelectric (TE) devices, both TE generators (TEGs) and TE coolers (TECs), have short service lives as TE materials undergo degradation from sublimation, oxidation and reactions in corrosive environments at high temperatures. We have investigated four high-temperature polymers (HTPs) as candidates for TE element coatings and/or TE device fillers to minimize or prevent this degradation. Two of these HTPs have shown good thermal stability in the 400–500 °C temperature range. The coatings were initially applied to bismuth telluride (Bi2Te3)-based TE materials that are used for commercial power generation devices specified for operation up to 250 °C. The HTPs protect the Bi2Te3 from both weight loss and weight gain up to 500 °C. This is clearly outside the optimum TE operation range of Bi2Te3 materials, but demonstrates the ability of the HTP coatings to protect the Bi2Te3 materials at least up to 250 °C. The properties that HTP materials demonstrated during the examination of suitability of their use for TE element coatings and/or TE device fillers using Bi2Te3are expected to hold good for higher operating temperature TE materials also.

(Received June 17 2012)

(Accepted September 04 2012)

Key Words:

  • high-temperature polymeric coatings;
  • thermoelectric generators;
  • Bi2Te3 ;
  • sealants;
  • ceramic coatings

Correspondence:

c1 Address all correspondence to this author. e-mail: wbrostow@yahoo.com

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