Method for rapidly preparing Bi2Te3-based thermoelectric material with high orientation and high power factor

A technology of high power factor and thermoelectric materials, which is applied in the field of rapidly preparing p-type or n-type Bi2Te3-based thermoelectric materials with high orientation and high power factor, which can solve the problems of increasing the internal resistance of thermoelectric devices, affecting the performance of thermoelectric devices, and decreasing the electrical conductivity. , to achieve the effect of high power factor, shortened preparation time, and shortened hot forging time

Inactive Publication Date: 2020-11-03
WUHAN UNIV OF TECH
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

However, while the materials prepared by nanostructure have low thermal conductivity, the electrical conductivity is also greatly reduced, result...

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  • Method for rapidly preparing Bi2Te3-based thermoelectric material with high orientation and high power factor
  • Method for rapidly preparing Bi2Te3-based thermoelectric material with high orientation and high power factor
  • Method for rapidly preparing Bi2Te3-based thermoelectric material with high orientation and high power factor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] A rapid preparation of p-type Bi with high orientation and high power factor 2 Te 3 The method for base thermoelectric material, concrete steps are as follows:

[0033] (1) Using high-purity elemental Bi, Sb, and Te as initial raw materials, according to Bi 0.4 Sb 1.6 Te 3 The stoichiometric ratio of each element in the formula weighs the high-purity element, mixes it and presses it into tablets, vacuum seals it in a glass tube, and performs thermal explosion synthesis (thermal explosion temperature 550°C, time 60s) to obtain p-type Bi 2 Te 3 bulk thermoelectric material;

[0034] (2) p-type Bi obtained in step (1) 2 Te 3 The base thermoelectric material block is manually ground to obtain a powder with a smaller particle size for 10 minutes, and the powder between 200 and 400 meshes is sieved for use;

[0035] (3) Fill the powder between 200 and 400 mesh obtained in step (2) into a graphite mold with a diameter of 12.7mm, the spark plasma sintering pressure is 4...

Embodiment 2

[0046] The difference between this example and Example 1 lies in that: step (4) the hot forging pressure is 30 MPa, the heat preservation is 8 minutes, and the extrusion ratio is 1:4.

[0047] The comparison of thermoelectric properties between the SPS sample and the hot forged sample in Example 2 is given below. Table 4 shows the conductivity data of the samples at different temperatures, Table 5 shows the Seebeck data at different temperatures of the samples, and Table 6 shows the power factor data of the samples at different temperatures. It can be seen from Table 4-6 that a larger extrusion ratio and a larger hot forging pressure can make the hot forging effect more obvious, the material orientation is stronger, and a higher electrical conductivity and power factor can be obtained.

[0048] Table 4 - Conductivity (10 4 S / m)

[0049] Example 2 300K 325K 350K 375K 400K SPS sample 12.33 10.84 9.5 8.4 7.45 Hot forged sample 14.27 12.76 11.17 ...

Embodiment 3

[0055] The difference between this example and Example 1 is that in step (4), the hot forging temperature is 450°C, the hot forging pressure is 30MPa, the heat preservation is 8min, and the extrusion ratio is 1:4; The outer ring part of the sample obtained by hot forging was cut off to obtain a cylindrical sample with a diameter of 12.7mm. The second hot forging was carried out. Specifically, the extrusion ratio was 1:4, the sintering temperature was 450°C, and the heating rate was 100°C / min. , the hot forging pressure was 30MPa, and the heat preservation time was 8min, and the hot forging samples with stronger orientation were obtained.

[0056] The following is a comparison of the thermoelectric properties of the SPS sample in Example 3 and the sample after hot forging 2 times. Table 7 shows the conductivity data of the sample at different temperatures, Table 8 shows the Seebeck data at different temperatures of the sample, and Table 9 shows the power of the sample at differe...

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Abstract

The invention discloses a method for rapidly preparing a p-type or n-type Bi2Te3-based thermoelectric material with high orientation and high power factor, and belongs to the technical field of energymaterials. The method is divided into three parts of compound preparation, forming and hot forging, and comprises the following steps that at first, high-purity Bi, Sb, Te, Se and S are weighed according to a stoichiometric ratio, and the p-type or n-type Bi2Te3-based thermoelectric material is extremely rapidly prepared through a self-propagating synthesis or thermal explosion synthesis manner;then the p-type or n-type Bi2Te3-based thermoelectric material is ground and screened, and the material with a proper particle size is selected for spark plasma sintering to obtain a compact block material; and the compact block material is subjected to hot forging through a spark plasma sintering technology to obtain the p-type or n-type Bi2Te3-based thermoelectric material with high orientationand high power factor. According to the method, the time required for raw material preparation and the time required for conducting grinding to reach the required particle size can be greatly shortened through the thermal explosion and self-propagating combustion synthesis technology, hot forging is conducted in combination with the spark plasma sintering technology, the grain growth can be effectively controlled, the time is short, and the material has high orientation and high power factor.

Description

technical field [0001] The invention belongs to the technical field of energy materials and provides a method for rapidly preparing p-type or n-type Bi with high orientation and high power factor 2 Te 3 approach to thermoelectric materials. [0002] technical background [0003] As a new type of clean renewable energy material, thermoelectric materials can realize the direct conversion of heat energy and electric energy. They have excellent characteristics such as no pollution, no loss, and high reliability. They are expected to greatly improve energy utilization and alleviate environmental pollution. Among them, bismuth telluride-based compounds are commercially used thermoelectric materials with the best performance near room temperature. The bismuth telluride-based compound is a trigonal crystal system, which belongs to the space group R-3m, and is formed by stacking hexagonal layered structures. Bi 2 Te 3 The compound along the crystallographic c-axis direction is -T...

Claims

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Application Information

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IPC IPC(8): C22C12/00B22F3/105B22F3/17B22F9/04C22C1/04
CPCB22F3/17B22F9/04C22C1/04C22C12/00
Inventor 唐新峰张政楷苏贤礼曹宇
Owner WUHAN UNIV OF TECH
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