Preparation method for p-type Bi0.5Sb1.5Te3-based nano-porous thermoelectric composite material

Abstract

The invention provides a preparation method for a p-type Bi0.5Sb1.5Te3-based nano-porous thermoelectric composite material. The method includes the steps that 3-5-micrometer Sn welding paste is spread on a p-type thermoelectric material Bi0.5Sb1.5Te3, the p-type thermoelectric material Bi0.5Sb1.5Te3 is placed on a heating table, a liquid phase wetting reaction is conducted in the Ar gas protection atmosphere at the temperature being 260 DEG C, and a uniform mixing layer of the Sn welding paste and a resultant SnTe-SbSn is formed, wherein tin oxidation is avoided due to the fact that the reaction is conducted in the Ar gas atmosphere, and the thickness and the micro-structure of the resultant SnTe-SbSn generated due to the reaction of the mixing layer can be controlled through reaction time and reaction temperature; ultrasonic concussion and acid pickling are conducted on a reaction pair composed of the reacted thermoelectric material Bi0.5Sb1.5Te3 and Sn welding paste, and then the p-type Bi0.5Sb1.5Te3 / porous SnTe-SbSn thermoelectric composite material with uniformly-distributed pores is obtained. The preparation method has the advantages that a SnTe-SbSn layer with uniform 200-500-micrometer nano-pores is acquired through the preparation method, the thickness of a reaction layer is increased to 40 micrometers, the reaction speed is 4.05 micrometers per minute, cost is low, and components can be accurately controlled.

Description

technical field [0001] The invention relates to the preparation of thermoelectric composite materials, using a p-type Bi in situ liquid phase wetting reaction plus acidification treatment 0.5 Sb 1.5 Te 3 Preparation method of nanoporous thermoelectric composite material. Background technique [0002] Thermoelectric materials refer to semiconductor functional materials that realize the mutual conversion between thermal energy and electrical energy through the transport and interaction of carriers and phonons in solid materials. Compared with other traditional energy technologies, thermoelectric power generation technology has the advantages of simple structure, no noise, no pollution, no transmission parts and long service life, so thermoelectric materials have been used in the automotive industry, metallurgical industry, information technology, aerospace and instrumentation Instruments and other fields have been widely used. For example, the use of thermoelectric technolo...

AI Technical Summary

Problems solved by technology

However, despite the wide application potential of thermoelectric materials and devices, due to the low conversion efficiency and high cost of traditional thermoelectric materials, their dimensionless thermoelectric figure of merit ZT has been hovering around 1. The conversion efficiency is less than 10%, which is far lower than that of traditional physical and chemical power sources, so the bottleneck of thermoelectric materials is an important factor restricting the further commercialization of thermoelectric devices

[0004] For many years, scientists have been committed to the design of new thermoelectric materials and the development of advanced preparation processes. According to the calculation formula of ZT, to improve the material's dimensionless thermoelectric figure of merit ZT needs to reduce the material's thermal conductivity and increase the Seebeck coefficient and electrical conductivity. However, in conventional In bulk thermoelectric materials, these two aspects cannot be achieved at the same time, and they are mutually restrictive

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