Effect of Y doping at Co site on thermoelectric properties of Ca3Co4O9

作者：Fan, Youyu; Qing, Xiaoling^*; Zeng, Dechang^*

来源：Functional Materials Letters, 2020, 13(3): 2051009.

DOI：10.1142/S1793604720510091

• Sol-gel
• thermoelectric material
• doping
• thermoelectric property

In this work, our effort was to improve the thermoelectric properties of Ca3Co4O9 thermoelectric material. Ca3Co4-xYxO9 polycrystalline thermoelectric ceramics have been fabricated by sol-gel method plus spontaneous combustion and cold isostatic pressing process. The structure, surface topography and thermoelectric properties of Ca3Co4-xYxO9 polycrystalline thermoelectric were investigated by X-ray diffraction (XRD), SEM and ZEM3, respectively. The results showed that Y doping affected the microstructure and thermoelectric performance remarkable. With the increasing of Y doping, the electrical conductivity had a maximum value, and thermal conductivity has a minimum value. Seebeck coefficient gradually increased with Y doping content increasing always. The figure of merit was 0.07 at 673K for the Ca3Co3.7Y0.3O9 sample. The results showed that the thermoelectric performance of Ca3Co4O9 could be improved 39% with the substitution of Y than the un-doped.

• 单位
  中国科学院; 中国科学院广州能源研究所