International Round-Robin Testing of Bulk Thermoelectrics

Wang, Hsin ; Porter, Wallace D ; Bottner, Harold ; Konig, Jan ; Chen, Lidong ; Bai, Shengqiang ; Tritt, Terry M. ; Mayolett, Alex ; Smith, Charlene ; Harris, Fred ; Sharp, Jeff ; Lo, Jason ; Keinke, Holger ; Kiss, Laszlo I.

Oak Ridge National Laboratory

关键词: Specific Heat;    Probability;    Thermoelectric;    Testing;    Round-Robin;   

DOI  :  10.2172/1049790
RP-ID  :  ORNL/TM-2011/393
RP-ID  :  DE-AC05-00OR22725
RP-ID  :  1049790

美国|英语

来源: UNT Digital Library

【 摘 要 】

Two international round-robin studies were conducted on transport properties measurements of bulk thermoelectric materials. The study discovered current measurement problems. In order to get ZT of a material four separate transport measurements must be taken. The round-robin study showed that among the four properties Seebeck coefficient is the one can be measured consistently. Electrical resistivity has +4-9% scatter. Thermal diffusivity has similar +5-10% scatter. The reliability of the above three properties can be improved by standardizing test procedures and enforcing system calibrations. The worst problem was found in specific heat measurements using DSC. The probability of making measurement error is great due to the fact three separate runs must be taken to determine Cp and the baseline shift is always an issue for commercial DSC. It is suggest the Dulong Petit limit be always used as a guide line for Cp. Procedures have been developed to eliminate operator and system errors. The IEA-AMT annex is developing standard procedures for transport properties testing.