中国物理B ›› 2018, Vol. 27 ›› Issue (5): 57201-057201.doi: 10.1088/1674-1056/27/5/057201

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Thermoelectric properties of lower concentration K-doped Ca3Co4O9 ceramics

Ya-Nan Li(李亚男), Ping Wu(吴平), Shi-Ping Zhang(张师平), Sen Chen(陈森), Dan Yan(闫丹), Jin-GuangYang(杨金光), Li Wang(王立), Xiu-Lan Huai(淮秀兰)   

  1. 1 Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China;
    2 School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China;
    3 Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2018-02-05 修回日期:2018-03-09 出版日期:2018-05-05 发布日期:2018-05-05
  • 通讯作者: Ping Wu E-mail:pingwu@sas.ustb.edu.cn
  • 基金资助:
    Project supported by the National Key R&D Program of China (Grant No.2016YFB0601101) and the National Natural Science Foundation of China (Grant No.51476173).

Thermoelectric properties of lower concentration K-doped Ca3Co4O9 ceramics

Ya-Nan Li(李亚男)1, Ping Wu(吴平)1, Shi-Ping Zhang(张师平)1, Sen Chen(陈森)1, Dan Yan(闫丹)1, Jin-GuangYang(杨金光)1, Li Wang(王立)2, Xiu-Lan Huai(淮秀兰)3   

  1. 1 Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China;
    2 School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China;
    3 Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2018-02-05 Revised:2018-03-09 Online:2018-05-05 Published:2018-05-05
  • Contact: Ping Wu E-mail:pingwu@sas.ustb.edu.cn
  • Supported by:
    Project supported by the National Key R&D Program of China (Grant No.2016YFB0601101) and the National Natural Science Foundation of China (Grant No.51476173).

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摘要： The tuning of electron and phonon by ion doping is an effective method of improving the performances of thermoelectric materials. A series of lower concentration K-doped Ca3-xKxCo4O9 (x=0, 0.05, 0.10, 0.15) polycrystalline ceramic samples are prepared by combining citrate acid sol-gel method with cold-pressing sintering method. The single-phase compositions and plate-like grain morphologies of all samples are confirmed by x-ray diffraction and field emission scanning electron microscope. The effects of lower concentration K doping on the thermoelectric properties of the material are evaluated systematically at high temperatures (300-1026 K). Low concentration K doping causes electrical conductivity to increase up to 23% with little effect on the Seebeck coefficient. Simultaneously, the thermal conductivity of K-doped sample is lower than that of the undoped sample, and the total thermal conductivity reaches a minimum value of approximately 1.30 W·m-1·K-1, which may be suppressed mainly by the phonon thermal conduction confinement. The dimensionless figure-of-merit ZT of Ca2.95K0.05Co4O9 is close to 0.22 at 1026 K, representing an improvement of about 36% compared with that of Ca3Co4O9, suggesting that lower concentration K-doped Ca3Co4O9 series materials are promising thermoelectric oxides for high-temperature applications.

关键词: Ca3Co4O9, thermoelectric properties, ceramics

Abstract: The tuning of electron and phonon by ion doping is an effective method of improving the performances of thermoelectric materials. A series of lower concentration K-doped Ca3-xKxCo4O9 (x=0, 0.05, 0.10, 0.15) polycrystalline ceramic samples are prepared by combining citrate acid sol-gel method with cold-pressing sintering method. The single-phase compositions and plate-like grain morphologies of all samples are confirmed by x-ray diffraction and field emission scanning electron microscope. The effects of lower concentration K doping on the thermoelectric properties of the material are evaluated systematically at high temperatures (300-1026 K). Low concentration K doping causes electrical conductivity to increase up to 23% with little effect on the Seebeck coefficient. Simultaneously, the thermal conductivity of K-doped sample is lower than that of the undoped sample, and the total thermal conductivity reaches a minimum value of approximately 1.30 W·m-1·K-1, which may be suppressed mainly by the phonon thermal conduction confinement. The dimensionless figure-of-merit ZT of Ca2.95K0.05Co4O9 is close to 0.22 at 1026 K, representing an improvement of about 36% compared with that of Ca3Co4O9, suggesting that lower concentration K-doped Ca3Co4O9 series materials are promising thermoelectric oxides for high-temperature applications.

Key words: Ca3Co4O9, thermoelectric properties, ceramics

中图分类号:  (Thermoelectric and thermomagnetic effects)

  • 72.15.Jf
84.60.Rb (Thermoelectric, electrogasdynamic and other direct energy conversion) 81.05.Je (Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides))