High-temperature thermoelectric properties of Na/sub x/CoO/sub 2-/spl delta// single crystals

Proceedings ICT2001. 20 International Conference on Thermoelectrics (Cat. No.01TH8589) Pub Date : 2001-06-08 DOI:10.1109/ICT.2001.979851

K. Fujita, T. Mochida, K. Nakamura

{"title":"High-temperature thermoelectric properties of Na/sub x/CoO/sub 2-/spl delta// single crystals","authors":"K. Fujita, T. Mochida, K. Nakamura","doi":"10.1109/ICT.2001.979851","DOIUrl":null,"url":null,"abstract":"The thermoelectric properties of Na/sub x/CoO/sub 2-/spl delta// single crystal have been evaluated at high temperatures (300<T< 800 K) for the first time. The Na/sub x/CoO/sub 2-/spl delta// single crystals are prepared by a flux technique, and the flaky single crystals are very thin on the c-axis. The in-plane electrical resistivity (/spl rho/), the thermoelectric power (S) and the in-plane thermal conductivity (/spl kappa/) are measured in the range of 300 K to 800 K. The estimated power factor (PF=S/sup 2//spl middot//spl rho//sup -1/) and the figure-of-merit (Z=S/sup 2//spl middot//spl rho//sup -1//spl kappa//sup -1/) are about 2.4 mWm/sup -1/ K/sup -2/ and 0.12 mK/sup -1/ at 300 K, respectively. These factors increase with temperature, and reach the value of PF=7.7 mWm/sup -1/ K/sup -2/ and Z=1.5 mK/sup -1/ at 800 K, and the dimensionless value of ZT exceeds the criterion of 1. The PF and Z exceed the values of typical \"high temperature thermoelectric materials\". These results suggest that Na/sub x/CoO/sub 2-/spl delta// could be a very promising material for use in the high-temperature thermoelectric power generation devices.","PeriodicalId":203601,"journal":{"name":"Proceedings ICT2001. 20 International Conference on Thermoelectrics (Cat. No.01TH8589)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2001-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings ICT2001. 20 International Conference on Thermoelectrics (Cat. No.01TH8589)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/ICT.2001.979851","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}