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CN-122003090-A - Low-temperature P-type thermoelectric material and preparation method and application thereof

CN122003090ACN 122003090 ACN122003090 ACN 122003090ACN-122003090-A

Abstract

The invention relates to the field of thermoelectric semiconductor materials, and provides a low-temperature P-type thermoelectric material and a preparation method and application thereof, in order to solve the obvious problem of the P-type thermoelectric material in a low-temperature environment, wherein the chemical formula of the P-type thermoelectric material is Bi x Sb 2‑ x Te 3 M y , x=0.5-0.7, y=0.001-0.003, M is one or more of Cu, pb and Mn, the thermoelectric performance of the material in a low-temperature area is improved through component optimization and doping design and preparation process optimization, the thermoelectric performance of the material in a real low-temperature area is improved by 18 percent basically, and the thermoelectric performance of the material in the real low-temperature area is improved to 0.95@225K from 0.75 which is generally purchased in market, and the P-type thermoelectric material can be applied to the deep refrigeration field.

Inventors

  • TANG ZEFENG
  • WU YONGQING
  • LIU FENG
  • LI MING
  • CUI BORAN

Assignees

  • 浙江先导热电科技股份有限公司

Dates

Publication Date
20260508
Application Date
20251223

Claims (10)

  1. 1. The low-temperature P-type thermoelectric material is characterized in that the chemical formula of the low-temperature P-type thermoelectric material is Bi x Sb 2- x Te 3 M y , wherein x=0.5-0.7, y=0.001-0.003, and M is one or more of Cu, pb and Mn.
  2. 2. The method for preparing a low temperature P-type thermoelectric material according to claim 1, wherein the method comprises the steps of: (1) Bi, sb, te, M weighing raw materials according to a stoichiometric ratio Bi x Sb 2-x Te 3 M y , placing the raw materials into a quartz tube, vacuum sealing the tube, placing the tube into a swinging furnace for swinging smelting after sealing the tube, and finally taking out the quartz tube and cooling the quartz tube in air; (2) Filling the cast ingot obtained in the step (1) into an extrusion die, and extruding at high temperature and high pressure along the direction of an outlet of the die to obtain a P-type extrusion material; (3) And (3) annealing the P-type extruded material obtained in the step (2) under vacuum heating to obtain the low-temperature P-type thermoelectric material.
  3. 3. The method of manufacturing a low temperature P-type thermoelectric material according to claim 2, wherein Bi, sb, te, M in the step (1) is sequentially placed in a quartz tube in order of melting point or boiling point from low to high.
  4. 4. The method for preparing a low-temperature P-type thermoelectric material according to claim 2, wherein the pressure in the tube is made to be less than 2 Pa after tube sealing in the step (1), and the tube is put into a swinging furnace for swinging smelting 1-2 h.
  5. 5. The method of manufacturing a low temperature P-type thermoelectric material according to claim 2 or 4, wherein the temperature of the rocking furnace in step (1) is 800 to 1000 ℃.
  6. 6. The method for preparing a low temperature P-type thermoelectric material according to claim 2, wherein the extrusion temperature in the step (2) is 300 to 500 ℃ and the pressure is 100 to 300MPa.
  7. 7. The method for preparing a low temperature P-type thermoelectric material according to claim 2, wherein the extrusion ratio of the die in step (2) is 9-27:1, and the extrusion speed is 1-12mm/min.
  8. 8. The method for producing a low-temperature P-type thermoelectric material according to claim 2 or 7, wherein when M is selected from Pb, mn, the extrusion speed is preferably 1 to 6mm/min.
  9. 9. The method of manufacturing a low temperature P-type thermoelectric material according to claim 2, wherein the annealing temperature in step (3) is 300 to 400 ℃ and the time is 5 to 15 h.
  10. 10. Use of the low temperature P-type thermoelectric material of claim 1 for deep refrigeration.

Description

Low-temperature P-type thermoelectric material and preparation method and application thereof Technical Field The invention relates to the field of thermoelectric semiconductor materials, in particular to a P-type thermoelectric material for deep refrigeration and a preparation method thereof. Background Thermoelectric refrigeration technology is based on Seebeck effect and Peltier effect, realizes electric and thermal conversion, and is widely applied to the fields of electronic cooling, medical equipment, aerospace and the like, and a detection chip is often required to operate in a low-temperature environment. The (Bi, sb) 2Te3 -based thermoelectric material is a P-type thermoelectric material commonly used in commercialization at present, the preparation process is relatively mature, the production efficiency is high, powerful support is provided for the wide application of the (Bi, sb) 2Te3 -based thermoelectric material in the low-temperature refrigeration field, so far, research on the (Bi, sb) 2Te3 -based thermoelectric material is mainly focused on optimizing the thermoelectric performance in the room temperature region and above, the thermoelectric material with the excellent performance in the room temperature region is difficult to meet the application requirement of a multi-stage thermoelectric device below room temperature, the thermoelectric performance of the thermoelectric material at the low temperature is required to be improved, the material is required to have smaller band gap and lower carrier concentration at the low temperature, the peak temperature corresponding to the thermoelectric performance is required to be shifted to the low temperature, however, the conventional P-type bismuth telluride-based thermoelectric material has obvious problems in the low-temperature environment (such as 200K-250K), the refrigeration quality of the prepared multi-layer product refrigeration device is insufficient, the thermoelectric quantity is limited, the thermoelectric performance is poor in the deep refrigeration field, and the deep development problem of the deep refrigeration field is limited. This is mainly due to the large forbidden bandwidth of the (Bi, sb) 2Te3 material, low carrier excitation efficiency at low temperatures, and reduced thermoelectric performance. Meanwhile, if the forbidden bandwidth is reduced once, bipolar diffusion is introduced, the thermal conductivity is obviously increased, and the material performance is further reduced. Around the development of thermoelectric materials in low temperature areas, researchers have conducted a great deal of attempts, CN102496676B discloses a niobium doped bismuth-antimony series low temperature thermoelectric material and a preparation method thereof, wherein the composition formula of the material is Bi 85Sb15-xNbx, x is any numerical value between 0 and 15, the preparation method is to prepare Bi, sb and Nb powder according to chemical proportion by adopting a mechanical alloying and ultrahigh pressure process, the material has excellent thermoelectric performance near 200K, the material has the characteristics of high mechanical strength, good thermoelectric potential and conductivity, higher quality at low temperature and the like, and the material has stable performance, simple and convenient manufacturing process, low cost and easy popularization and application. However, it is seen from the drawings that the ZT value is 0.35 or less, the ZT value is still relatively low, and in Bi, sb binary phase diagrams, although Bi, sb are represented as continuous solid solutions, it is difficult to obtain a sample having a uniform composition due to a large gap between liquidus and solid phase lines and a low inter-diffusion coefficient between Bi, sb elements. Therefore, development of a high-performance low-temperature P-type bismuth telluride-based thermoelectric material is urgently needed. Disclosure of Invention In order to solve the obvious problem of the P-type thermoelectric material in a low-temperature environment, the invention provides the low-temperature P-type thermoelectric material, and the preparation method and the application thereof, and the thermoelectric performance of the material in a low-temperature area is improved through component optimization, doping design and preparation process optimization. In order to achieve the purpose, the low-temperature P-type thermoelectric material adopts the following technical scheme that the chemical formula of the low-temperature P-type thermoelectric material is Bi xSb2-xTe3My, wherein x=0.5-0.7, y=0.001-0.003, and M is one or more of Cu, pb and Mn. The improvement of thermoelectric performance of the material at low temperature requires that the material has smaller band gap and lower carrier concentration, and meanwhile, the influence of bipolar diffusion is reduced, the peak temperature corresponding to the thermoelectric performance is shifted to low temperature, bi xSb