Preparation method of nanocrystalline Cu-S-based block thermoelectric material

Abstract

The invention discloses a preparation method of a nanocrystalline Cu-S-based block thermoelectric material, and belongs to the technical field of thermoelectric materials. A mechanical alloying reaction is combined with an indoor temperature high-pressure sintering technology, elementary substance Cu powder, S powder and doping element A powder are taken as raw materials, A is Se or Te, and according to the chemical general formula Cu2-xS1-yAy, preparation is conducted, wherein x is greater than or equal to 0 and less than or equal to 0.2, and y is greater than or equal to 0 and less than or equal to 0.5; through the mechanical alloying reaction, high-sintering-activity nanoscale pre-synthesized powder is obtained, and then in combination with the indoor temperature high-pressure sinteringtechnology, the nanocrystalline Cu-S-based block thermoelectric material with uniform components, fine crystal particles and a compact structure is prepared. The prepared nanocrystalline Cu-S-based block thermoelectric material is of a nanocrystalline structure, the crystal particle size is 10-80 nanometers, the structure is compact, the relative density is greater than 97%, composition components are uniform in distribution, and the power factor is 1.1*10<-4>-7.5*10<-4>Wm<-1>K<-2> under the 623K condition. According to the preparation method, S element volatilization can be effectively inhibited, the crystal particle size can be effectively controlled, effective solid dissolution of the doping element in a base material can be effectively promoted, and adjustment and control over the thermoelectric performance in a larger component range are facilitated.

Description

technical field [0001] The invention belongs to the technical field of thermoelectric materials, and relates to mechanical alloying reaction and normal temperature and high pressure sintering technology, in particular to a method for preparing nanocrystalline Cu-S-based block thermoelectric materials. Background technique [0002] The world's increasing demand for energy, the depletion of fossil energy, and the serious environmental pollution caused by the use of fossil energy have aroused widespread concern around the world. Guaranteeing reliable and cheap energy supply, realizing efficient energy use, low-carbon environmental protection has become the top priority of energy policies of various governments. Thermoelectric materials are functional materials that can directly convert heat and electricity into each other. Thermoelectric conversion devices have the characteristics of small size, high reliability, and no pollution. They have broad application prospects in the f...

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Problems solved by technology

[0005] So far, the preparation of Cu-S-based nano-precursor powder by mechanical alloying reaction, combined with room temperature and high-pressure sintering technology to prepare high-density nanocrystalline Cu-S-based bulk thermoelectric materials has not been reported.

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