Thermoelectric Performance Optimization of n-Type La3−xSmxTe4/Ni Composites via Sm Doping

Energies

Hongliang Dong¹  Ruiheng Liu²  Qingfeng Song³  Jian Li³  Shengqiang Bai³  Qihao Zhang³  Lidong Chen³  Xun Shi³ 

[1] Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China;Institute of Advanced Materials Science and Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China;State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China;

关键词: thermoelectric;    lanthanum telluride;    carrier concentration optimization;    composite;   

DOI  :  10.3390/en15072353

来源: DOAJ

【 摘 要 】

La₃Te₄-based rare-earth telluride is a kind of n-type high-temperature thermoelectric (TE) material with an operational temperature of up to 1273 K, which is a promising candidate for thermoelectric generators. In this work, the Sm substitution in La_3−xSm_xTe₄/Ni composites is reported. The electrical transport property of La_3−xSm_xTe₄ is modified by reducing carrier concentration due to the substitution of Sm²⁺ for La³⁺. The electric thermal conductivity decreases by 90% due to carrier concentration reduction, which mainly contributes to a reduction in total thermal conductivity. Lattice thermal conductivity also decreases by point-defect scattering by Sm doping. Meanwhile, based on our previous study, compositing nickel improves the thermal stability of the La_{3 − x}Sm_xTe₄ matrix. Finally, combined with carrier concentration optimization and the decreased thermal conductivity, a maximum zT of 1.1 at 1273 K and an average zT_ave value of 0.8 over 600 K–1273 K were achieved in La_2.315Sm_0.685Te₄/10 vol.% Ni composite, which is among the highest TE performance reported in La₃Te₄ compounds.

【 授权许可】

Unknown