Enhanced Thermoelectric Performance in the Ba0.3Co4Sb12/InSb Nanocomposite Originating from the Minimum Possible Lattice Thermal Conductivity
Enhanced Thermoelectric Performance in the Ba0.3Co4Sb12/InSb Nanocomposite Originating from the Minimum Possible Lattice Thermal Conductivity
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DOI：
10.1021/acsami.0c17254
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发表时间：
2020-10-28
影响因子：
9.5
通讯作者：
Mallik, Ramesh Chandra
中科院分区：
文献类型：
--
作者：
Ghosh, Sanyukta;Shankar, Gyan;Mallik, Ramesh Chandra
通过纳米第二相均匀分散在填充Co4Sb12的基质中，降低晶格热导率，可以提高Skutterudite材料的热电效率。本文采用球磨和放电等离子烧结的方法制备了Ba0.3Co4Sb12/InSb纳米复合材料。在4.2~773K温度范围内研究了材料的热电输运特性，发现由于InSb纳米颗粒的团聚，在Ba0.3Co4Sb12颗粒中弥散分布着约20 nm的InSb纳米颗粒，其中较大的颗粒约为10µm。由于Co_4Sb_(12)中的+2氧化态，导致基质的电阻率偏低。InSb的加入提高了Ba0.3Co4Sb12的塞贝克系数S和电阻率，这归功于界面低能电子的能量过滤作用。由于复合材料的功率因数很高，与母材相比不能得到提高。价值。最小的晶格热导率(773K时为0.45W/m.K)是由于纳米InSb颗粒在空穴中引起的声子散射增强和空位中的Ba原子的相互作用共同作用的结果。结果表明，(InSb)0.15+Ba0.3Co4Sb12复合材料具有较好的热电性能，在773K时zT达到最大值1.4，且具有较高的硬度、较高的杨氏模量和较低的脆性。
The thermoelectric efficiency of skutterudite materials can be improved by lowering the lattice thermal conductivity via the uniform dispersion of a nanosized second phase in the matrix of filled Co4Sb12. In this work, nanocomposites of Ba0.3Co4Sb12 and InSb were synthesized using ball-milling and spark plasma sintering. The thermoelectric transport properties were studied from 4.2 to 773 K. The InSb nanoparticles of similar to 20 nm were found to be dispersed in the Ba0.3Co4Sb12 grains with a few larger grains of about 10 mu m due to the agglomeration of the InSb nanoparticles. The +2 oxidation state of Ba in Co4Sb12 resulted in a low electrical resistivity,., value of the matrix. The enhancement of the Seebeck coefficient, S, and the electrical resistivity values of Ba0.3Co4Sb12 with the addition of InSb can be credited to the energy-filtering effect of electrons with low energy at the interfaces. The power factor of the composites could not be enhanced compared to the matrix because of the very high. value. A minimum possible lattice thermal conductivity (0.45 W/m.K at 773 K) was achieved due to the combined effect of rattling of Ba atoms in the voids and enhanced phonon scattering at the interfaces induced by nanosized InSb particles. As a result, the (InSb) 0.15 + Ba0.3Co4Sb12 composite exhibited improved thermoelectric properties with the highest zT of 1.4 at 773 K and improved mechanical properties with a higher hardness, higher Young's modulus, and lower brittleness.