Preparation method of bismuth sulfide polycrystal thermoelectric material

Abstract

The invention discloses a method for optimizing the performance of a bismuth sulfide polycrystal thermoelectric material, and belongs to the technical field of energy materials. The method comprises the steps that bismuth sulfide powder synthesized through a mechanical alloying method or a solid phase method is adopted as precursor powder; a hydrothermal method is adopted, ethylene glycol is adopted as a solvent, hydrazine hydrate is adopted as a reducing agent, mixed bases of NaOH and KOH are adopted as a pH modifier, a hydrothermal reaction is performed under the temperature of 100-200 DEG C for 1-6 h, and bismuth sulfide / bismuth core-shell structure powder with the controllable surface bismuth layer thickness is obtained. The core-shell structure powder of different bismuth layer thicknesses is placed into a graphite mold, and a spark plasma sintering technology is adopted for performing sintering for 0-30 min under the temperature of 300-500 DEG C to prepare a bismuth sulfide polycrystal block. Equipment needed by the method is simple, and the method is easy to implement, low in cost and capable of greatly improving the electrical transmission performance of the bismuth sulfide polycrystal.

Description

technical field [0001] The invention relates to a preparation method of a bismuth sulfide polycrystalline thermoelectric material, belonging to the technical field of energy materials. Background technique [0002] With the continuous development of social economy, environmental and energy issues are paid more and more attention by human beings. Thermoelectric materials can directly realize the mutual conversion of heat energy and electric energy. Thermoelectric devices are non-polluting, light in structure, small in size and long in life, and are increasingly concerned by people. Thermoelectric modules with thermoelectric devices as core components have broad application prospects in semiconductor refrigeration and thermoelectric batteries. The thermoelectric performance is characterized by the dimensionless thermoelectric figure of merit ZT, ZT=TS 2 σ / κ, S is Seebeck coefficient, σ is electrical conductivity, κ is thermal conductivity, T is absolute temperature; S 2 σ i...

AI Technical Summary

Problems solved by technology

Bi 2 S 3 As a thermoelectric material, the synthesis process is simple, the raw material is abundant, cheap, and low-toxicity has broad application prospects, but its ZT value still has a lot of room for improvement.

And Bi 2 S 3 The main problem of the low ZT value of the material is the low electrical conductivity

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