Filled skutterudite-base thermoelectrical composite material and its prepn

Abstract

The present invention relates to filled skuterudite-base thermoelectrical composite material and its preparation process, and belongs to the field of thermoelectrical material preparing technology. The thermoelectrical composite material has the composition of IyA4B12/zIOx, where I is one of Yb, Eu, Ce, La, Nd, Ca and Sr; A is Sb or its mixture with one of Ge, Sn, Te and Se; B is Co or its mixture with Fe or Ni; y is the amount of I element, y+z=m, and m is greater than the filling limit of filling atom. The thermoelectrical composite material is prepared through first smelting process to produce block material, the subsequent mechanical crushing and grinding to obtain powder, and the final fast sintering with pulse DC current to form compact block. The material has lowered lattice heat conductivity, maintained electric transmission performance and raised thermoelectrical conversion performance.

Description

technical field [0001] The invention relates to a filled skutterudite-based thermoelectric composite material and a preparation method thereof, belonging to the field of thermoelectric materials. Background technique [0002] Thermoelectric conversion technology is a technology that directly converts thermal energy and electrical energy. It has the characteristics of no moving parts, no noise, high reliability, and long life. It has broad application prospects in aerospace, information and communication fields. The application of thermoelectric conversion technology mainly depends on the dimensionless performance index ZT value of thermoelectric materials (ZT=α 2 σT / κ, where α is the Seebeck coefficient; σ is the electrical conductivity; κ is the thermal conductivity, and T is the absolute temperature), the higher the ZT value, the better the material performance. [0003] Filled skutterudite compound is one of the materials with the best thermoelectric conversion performan...

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Problems solved by technology

However, the lattice thermal conductivity of this type of material is still high. In order to further reduce the lattice thermal conductivity of filled skutterudite compounds, a second phase can be added to the matrix to form a composite material, and phonon scattering defects are introduced to reduce the crystal lattice thermal conductivity. Lattice thermal conductivity

S.Katsuyama et al. (J.Appl.Phys.88.3484) added FeSb by ball milling 2 Particle preparation of CoSb 3 Matrix composite materials, this method is complicated, FeSb 2 Easy to agglomerate and unstable at high temperature, easy to decompose impurity Fe, and Fe is easy to react with the matrix to change the composition of the matrix

Shi Xun et al. (Acta Phys. 53.1409) prepared CoSb by solid phase reaction method 3 / C 60 composite materials, and on the CoSb 3 and Ba y co 4 Sb 12 C 60 , BN and other inert nanoparticles to prepare CoSb 3 The method of matrix composite material has applied for an invention patent (application number 200410025544.X), but the crystallinity of the material prepared by the above method is poor, and the process is relatively complicated, the material preparation cycle is long, and the particle size and distribution of the second phase added outside are difficult to control. Agglomeration is easy to occur, and it is difficult to obtain a composite thermoelectric material with a uniform distribution of the second phase

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