A high-performance thermoelectric thick film and a method for rapidly preparing the high-performance thermoelectric thick film

Abstract

The present application relates to a kind of high-performance thermoelectric thick film preparation method for fast preparation, the preparation of thermoelectric thick film is realized by the way of powder metallurgy, with thermoelectric powder as raw material, under the assistance of pre-pressing mould, first by the method of pre-pressing forming realizes the effective control of the uniformity and thickness of thermoelectric thick film, then high pressure cold pressing and annealing obtains high-density thermoelectric thick film, finally the prepared thermoelectric thick film not only surface is smooth, but also has high thermoelectric performance.The method described in the present application can realize the preparation of thermoelectric thick film with thickness below 200 μm, and has very good compatibility, and can be used for the preparation of various low, medium and high temperature thermoelectric material thick film.The process of the method of the present application is simple, the cost of materials and equipment is low, the large-scale industrialization of high-performance thermoelectric thick film can be realized, further build various high-performance micro thermoelectric generator or refrigeration device, including high-density or flexible thermoelectric device, so as to lay the foundation for the rapid development of high-performance micro thick film thermoelectric device.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of thermoelectric materials, and particularly relates to a high-performance thermoelectric thick film and a method for rapidly preparing the high-performance thermoelectric thick film. BACKGROUND

[0002] The thermoelectric conversion technology based on thermoelectric materials can realize temperature difference power generation through the Seebeck effect or rapid refrigeration through the Peltier effect, is a new energy technology capable of realizing direct mutual conversion between thermal energy and electrical energy, and has many advantages such as no moving parts, no noise, no pollution, portability, miniaturization, long-term stability and the like, and has a wide range of applications in waste heat energy collection and precise temperature control. At present, the commercialized thermoelectric power generation or refrigeration devices are all constructed by using bulk thermoelectric materials, that is, the thickness of the thermoelectric arm is generally greater than 500 μm, which limits the further miniaturization of the thermoelectric device. The bulk refrigeration device also has the shortcomings of low refrigeration power density and slow response speed. Although the thermoelectric device constructed by the thermoelectric thin film with a thickness of less than 10 μm can make up for the shortcomings of the bulk device, it is difficult to produce a larger refrigeration temperature difference. The thermoelectric refrigeration device constructed by the thermoelectric thick film with a thickness of 10-500 μm has the comprehensive performance of fast response speed and large refrigeration temperature difference, and the thick film thermoelectric device has the advantages of easy flexibility, miniaturization and high density. In recent years, the continuous miniaturization of electronic devices and the development of wearable devices have put forward urgent demands for precise temperature control, rapid refrigeration and flexible micro self-power supply of micro devices, and therefore it is of great significance to develop a method for rapidly preparing high-performance thermoelectric thick films to develop thick film thermoelectric devices.

[0003] At present, the thermoelectric thick film is mainly prepared by the methods of cutting and thinning or thermoelectric paste printing. The method of cutting and thinning is difficult to cut the thermoelectric bulk to a thickness of less than 200 μm, and repeated mechanical processing will cause secondary damage to the material. The method of thermoelectric paste printing first configures the thermoelectric powder, adhesive, organic solvent and dispersant into a thermoelectric paste with suitable viscosity, then prints the thermoelectric paste into a film, then dries the solvent, and finally sintering removes the organic components to obtain the thermoelectric thick film. This method has the following shortcomings: 1. The process is relatively complex; 2. Toxic organic substances are usually used to prepare the paste; 3. The surface of the prepared thermoelectric thick film is rough; 4. After sintering to remove the organic components, holes and cracks are left in the thick film, resulting in poor compactness and low thermoelectric performance of the thermoelectric thick film. The power factor of the Bi2Te3-based thermoelectric thick film prepared by this method is usually less than 20 μW·cm -1 ·K -2 Therefore, it is urgent to develop a new and more simple and environmentally friendly method to rapidly prepare high-performance thermoelectric thick films. SUMMARY

[0004] In order to solve the above problems existing in the prior art, the application provides a high-performance thermoelectric thick film and a method for rapidly preparing the high-performance thermoelectric thick film. The method is a powder metallurgy method, and high-performance thermoelectric thick films are directly prepared by tabletting and sintering under the assistance of a pre-pressing mold, so that the high-performance thermoelectric thick films can be rapidly prepared on a large scale and industrialized, and the method has the advantages of simple process and low material and equipment cost.

[0005] The technical scheme adopted by the application is as follows:

[0006] The application provides a method for rapidly preparing high-performance thermoelectric thick films by adopting a powder metallurgy method.

[0007] The method for preparing high-performance thermoelectric thick films by adopting the powder metallurgy method comprises the following steps:

[0008] (1) Pre-pressing forming: thermoelectric powders are laid flat in a pre-pressing mold, and then a proper pressure is applied to obtain a tablet-shaped thermoelectric thick film;

[0009] (2) The tablet-shaped thermoelectric thick film obtained in step (1) is subjected to high-pressure cold-pressing pressing, and the pressure is maintained for a certain time, so that a densified thermoelectric thick film is obtained;

[0010] (3) The densified thermoelectric thick film obtained in step (2) is subjected to annealing sintering, so that the high-performance thermoelectric thick film is obtained.

[0011] In step (1), the particle size of the thermoelectric powders is less than the thickness of the tablet-shaped thermoelectric thick film.

[0012] In step (1), the thermoelectric powders are Bi2Te3-based thermoelectric powders.

[0013] The Bi2Te3-based thermoelectric powders are Bi2Te3 or Bi 0.5 Sb 1.5 Te3.

[0014] In step (1), when the pressing is performed, the applied pressure is 100-400 MPa.

[0015] In step (1), the pre-pressing mold is made of a hard material.

[0016] In step (2), the pressure for the cold-pressing pressing is 400-1200 MPa, and the pressure maintaining time is 1-10 min.

[0017] In step (3), the sintering is performed in an argon atmosphere at one atmosphere.

[0018] The annealing sintering temperature is 300-500 DEG C, and the annealing time is 0.5-2 h.

[0019] The high-performance thermoelectric thick film prepared by the method.

[0020] The present application has the following advantages:

[0021] The method for rapidly preparing high-performance thermoelectric thick film provided by the present application uses a powder metallurgy method, takes a thermoelectric powder as a raw material, and realizes effective control of the uniformity and thickness of the thermoelectric thick film through pre-pressing forming with the assistance of a pre-pressing mold, then high-pressure cold pressing and annealing to obtain a high-density thermoelectric thick film, and finally obtaining a thermoelectric thick film which is not only flat but also has high thermoelectric performance. Experimental data show that the power factor of the n-Bi2Te3 thick film prepared by the method of the present application can reach 26 μW·cm-1·K-2 at room temperature. -1 ·K -2 , the power factor of the p-Bi 0.5 Sb 1.5 Te3 thick film can reach 29 μW·cm-1·K-2 at room temperature. -1 ·K -2 The method of the present application can realize the preparation of a thermoelectric thick film with a thickness of 200 μm or less, and has very good compatibility and can be used for the preparation of various low, medium and high temperature thermoelectric material thick films. The method of the present application has the advantages of simple process and low material and equipment cost, can realize large-scale industrialized rapid preparation of high-performance thermoelectric thick film, and can construct various high-performance micro thermoelectric power generation or refrigeration devices by patterning the thermoelectric thick film into a micro thermoelectric arm through laser cutting or micro mechanical cutting, including high-density or flexible thermoelectric devices. Therefore, the method of the present application will lay a solid foundation for the rapid development of high-performance micro thermoelectric devices. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 The preparation process flow chart of the n-type Bi2Te3 thermoelectric thick film described in embodiment 1 of the present application;

[0024] Figure 2A The trend chart of the electrical conductivity, Seebeck coefficient and power factor of the 150 μm thick n-type Bi2Te3 thermoelectric thick film described in embodiment 1 with the change of the annealing temperature;

[0025] Figure 2BTrends of electrical conductivity, Seebeck coefficient and power factor of the 150 μm thick n-type Bi2Te3 thermoelectric thick film described in Example 1 as a function of annealing time;

[0026] Figure 2C Trends of electrical conductivity, Seebeck coefficient and power factor of the 150 μm thick n-type Bi2Te3 thermoelectric thick film described in Example 1 as a function of cold-pressing pressure;

[0027] Figure 3A Trends of electrical conductivity, Seebeck coefficient and power factor of the 150 μm thick p-type Bi 0.5 Sb 1.5 Te3 thermoelectric thick film described in Example 2 as a function of annealing temperature;

[0028] Figure 3B Trends of electrical conductivity, Seebeck coefficient and power factor of the 150 μm thick p-type Bi 0.5 Sb 1.5 Te3 thermoelectric thick film described in Example 2 as a function of annealing time;

[0029] Figure 3C Trends of electrical conductivity, Seebeck coefficient and power factor of the 150 μm thick p-type Bi 0.5 Sb 1.5 Te3 thermoelectric thick film described in Example 2 as a function of cold-pressing pressure;

[0030] Figure 4 Scanning electron micrograph of the cross-sectional morphology of the 29 μm thick Bi2Te3 thermoelectric thick film described in Example 3;

[0031] Figure 5 Scanning electron micrograph of the cross-sectional morphology of the 52 μm thick Bi2Te3 thermoelectric thick film described in Example 4;

[0032] Figure 6 Scanning electron micrograph of the cross-sectional morphology of the 106 μm thick Bi2Te3 thermoelectric thick film described in Example 5;

[0033] Figure 7 Scanning electron micrograph of the cross-sectional morphology of the 175 μm thick Bi2Te3 thermoelectric thick film described in Example 6. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in a detailed manner. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work should fall into the protection scope of the present application.

[0035] Embodiment 1

[0036] The embodiment provides a method for rapidly preparing a high-performance thermoelectric thick film, which is an n-type Bi2Te3 thermoelectric thick film with a thickness of 150 μm.

[0037] A preparation process flow of the n-type Bi2Te3 thermoelectric thick film is shown in Figure 1 and specifically comprises the following steps:

[0038] (1) a 250 μm deep groove is made on a 400 μm thick alumina flat plate as a pre-pressing mold for thermoelectric powder, and the pre-pressing mold is cleaned with ethanol;

[0039] Bi2Te3 thermoelectric powder with a particle size less than 70 μm is screened by a screen, 656 mg of the thermoelectric powder is weighed and placed in the groove of the pre-pressing mold, and the thermoelectric powder is just spread and leveled in the 250 μm deep groove; a 20 mm diameter press head is used to apply a pressure of 150 MPa on the leveled thermoelectric powder, and a 20 mm diameter thermoelectric film wafer is pressed out;

[0040] (2) the thermoelectric film wafer in step (1) is transferred to a high-hardness chromium steel high-pressure tabletting mold which can just place a 20 mm diameter wafer, a tabletting machine is used to apply a pressure of 400-1200 MPa and keep the pressure for 1 min, so as to realize densification of the thermoelectric thick film, and a densified thermoelectric thick film is obtained;

[0041] (3) the densified thermoelectric thick film in step (2) is transferred to a quartz tube furnace, vacuum is first extracted, then Ar gas is introduced, the Ar gas flow is 200 sccm, the Ar gas pressure is 1 atm, annealing sintering is performed, the annealing sintering temperature is 300-500 ℃, the annealing time is 0.5-2 h, and finally the n-type Bi2Te3 thermoelectric thick film with high thermoelectric performance and a thickness of 150 μm is prepared.

[0042] By fixing the cold-pressing pressure to be 800 MPa and the annealing time to be 1 h, the change trends of the electrical conductivity, the Seebeck coefficient and the power factor of the Bi2Te3 thick film with the annealing temperature in the range of 300-500 ℃ are studied, as shown in Figure 2A , and the power factor of the thermoelectric thick film prepared at an annealing temperature of 450 ℃ is the largest.

[0043] By fixing the cold-pressing pressure to be 800 MPa and the annealing temperature to be 450 ℃, the change trends of the electrical conductivity, the Seebeck coefficient and the power factor of the Bi2Te3 thick film with the annealing time in the range of 0.5-2 h are studied, as shown in Figure 2B , and the power factor of the thermoelectric thick film prepared at an annealing time of 1 h is the largest.

[0044] The change trend of the electrical conductivity, Seebeck coefficient and power factor of the Bi2Te3 thick film with the cold-pressing pressure in the range of 400-1200 MPa was studied by fixing the annealing temperature at 450℃ and the annealing time at 1h, as shown in Figure 2C The annealing sintering can greatly improve the thermoelectric performance of the Bi2Te3 thick film, and in the range of 400-1200 MPa, the greater the cold-pressing pressure, the higher the thermoelectric performance, but the influence is small.

[0045] The data show that the power factor of the 150μm-thick n-type Bi2Te3 thermoelectric thick film at room temperature can reach 26μW·cm -1 ·K -2 .

[0046] Embodiment 2

[0047] The embodiment provides a method for quickly preparing a high-performance thermoelectric thick film, and the thermoelectric thick film is a 150μm-thick p-type Bi 0.5 Sb 1.5 Te3 thermoelectric thick film.

[0048] The preparation method of the p-type Bi 0.5 Sb 1.5 Te3 specifically comprises the following steps:

[0049] (1) A 250μm-deep groove is made on a 400μm-thick alumina flat plate as a pre-pressing mold for thermoelectric powder, and the pre-pressing mold is cleaned with ethanol;

[0050] Bi 0.5 Sb 1.5 Te3 thermoelectric powder with a particle size of less than 70μm is screened out, 544mg of the thermoelectric powder is weighed and placed in the groove of the pre-pressing mold, and the thermoelectric powder is just spread and flattened in the 250μm-deep groove; a 20mm-diameter pressing head is used to apply a pressure of 150MPa to the spread thermoelectric powder to press a 20mm-diameter thermoelectric film wafer;

[0051] (2) The thermoelectric film wafer in step (1) is transferred to a high-hardness chromium steel-made high-pressure tabletting mold which can just place a 20mm-diameter wafer, and a tabletting machine is used to apply a pressure of 400-1200MPa and keep the pressure for 1min to realize the densification of the thermoelectric thick film, and a densified thermoelectric thick film is obtained;

[0052] (3) The thermoelectric thick film densified in step (2) is transferred into a quartz tube furnace, vacuumized, and then Ar gas is introduced at a flow rate of 200 sccm and a pressure of 1 atm, and then annealing sintering is performed at a temperature of 300-500°C for 0.5-2h, to obtain a 150μm-thick p-type Bi 0.5 Sb 1.5 Te3thermoelectric thick film.

[0053] By fixing the cold-pressing pressure at 800MPa and the annealing time at 1h, the trends of the electrical conductivity, Seebeck coefficient and power factor of the Bi 0.5 Sb 1.5 Te3thick film with different annealing temperatures are studied, as shown in Figure 3A Fig. 2, and it is found that the power factor of the p-type Bi 0.5 Sb 1.5 Te3thermoelectric thick film is the largest when the annealing temperature is 450°C.

[0054] By fixing the annealing temperature at 450°C and the annealing time at 1.5h, the trends of the electrical conductivity, Seebeck coefficient and power factor of the Bi 0.5 Sb 1.5 Te3thick film with different annealing times are studied, as shown in Figure 3B Fig. 3, and it is found that the power factor of the thermoelectric thick film is the largest when the annealing time is 1.5h.

[0055] By fixing the annealing temperature at 450°C and the annealing time at 1.5h, the trends of the electrical conductivity, Seebeck coefficient and power factor of the Bi 0.5 Sb 1.5 Te3thick film with different cold-pressing pressures are studied, as shown in Figure 3C Fig. 4, and it is found that the annealing sintering can greatly improve the thermoelectric performance of the Bi 0.5 Sb 1.5 Te3thick film, and the thermoelectric performance is generally higher when the cold-pressing pressure is higher within the range of 400-1200MPa, but the influence is small.

[0056] The data show that the power factor of the 150μm-thick p-type Bi 0.5 Sb 1.5 Te3thermoelectric thick film is up to 29μW·cm -1 ·K -2 .

[0057] Example 3

[0058] The embodiment provides a method for rapidly preparing a high-performance thermoelectric thick film, and the thermoelectric thick film is an n-type Bi2Te3 thermoelectric thick film with a thickness of 29 microns.

[0059] The method for preparing the n-type Bi2Te3 thermoelectric thick film comprises the following steps:

[0060] (1) a 40-micron-deep groove is made on a 400-micron-thick alumina flat plate as a pre-pressing mold for thermoelectric powder, and the pre-pressing mold is cleaned with ethanol;

[0061] Bi2Te3 thermoelectric powder with a particle size less than 10 microns is screened by a screen, 127 mg of the thermoelectric powder is weighed and placed in the groove of the pre-pressing mold, and the thermoelectric powder is just spread and flattened in the 40-micron-deep groove; a 20-mm-diameter pressing head is used to apply a pressure of 400 MPa on the flattened thermoelectric powder, and a 20-mm-diameter thermoelectric film wafer is pressed out;

[0062] (2) the thermoelectric film wafer in step (1) is transferred to a high-hardness chromium steel high-pressure tabletting mold which can just accommodate the 20-mm-diameter wafer, and a tabletting machine is used to apply a pressure of 800 MPa and keep the pressure for 10 minutes, so that the thermoelectric thick film is densified, and a densified thermoelectric thick film is obtained;

[0063] (3) the densified thermoelectric thick film in step (2) is transferred to a quartz tube furnace, vacuum is first drawn, and then Ar gas is introduced, the Ar gas flow is 200 sccm, the Ar gas pressure is 1 atm, annealing sintering is performed, the annealing sintering temperature is 450 DEG C, the annealing time is 1 h, and finally the n-type Bi2Te3 thermoelectric thick film with a thickness of 29 microns and high thermoelectric performance is prepared.

[0064] As Figure 4 FIG. 5 shows a scanning electron microscope image of a cross-sectional morphology of the 29-micron-thick Bi2Te3 thermoelectric thick film prepared by the method of the embodiment, and it can be seen from the figure that the thickness of the Bi2Te3 thermoelectric thick film is uniform, and the structure is dense. The power factor of the 29-micron-thick Bi2Te3 thermoelectric thick film is measured to be 25.78 muW·cm -1 ·K -2 .

[0065] Embodiment 4

[0066] The embodiment provides a method for rapidly preparing a high-performance thermoelectric thick film, and the thermoelectric thick film is an n-type Bi2Te3 thermoelectric thick film with a thickness of 52 microns.

[0067] The method for preparing the n-type Bi2Te3 thermoelectric thick film comprises the following steps:

[0068] (1) A 70-μm-deep groove was made on a 400-μm-thick alumina flat plate as a pre-pressing mold for the thermoelectric powder, and the pre-pressing mold was cleaned with ethanol;

[0069] Bi2Te3 thermoelectric powder with a particle size less than 30 μm was screened by a screen, 228 mg of the thermoelectric powder was weighed and placed in the groove of the pre-pressing mold, and the thermoelectric powder was just spread and leveled in the 70-μm-deep groove; a 20-mm-diameter pressure head was used to apply a pressure of 400 MPa on the spread thermoelectric powder, and a 20-mm-diameter thermoelectric film wafer was pressed;

[0070] (2) The thermoelectric film wafer described in step (1) was transferred to a high-pressure tabletting mold made of high-hardness chromium steel which can just accommodate a 20-mm-diameter wafer, and a tabletting machine was used to apply a pressure of 800 MPa and keep the pressure for 10 min to realize densification of the thermoelectric thick film, and a densified thermoelectric thick film was obtained.

[0071] (3) The densified thermoelectric thick film of step (2) was transferred to a quartz tube furnace, vacuumized, and then Ar gas was introduced at a flow rate of 200 sccm and a pressure of 1 atm, and annealing sintering was performed at a temperature of 450℃ for 1 h, and finally a 52-μm-thick n-type Bi2Te3 thermoelectric thick film with high thermoelectric performance was obtained.

[0072] As shown in FIG. 1, the method of the present embodiment comprises the following steps: Figure 5 FIG. 2 shows a scanning electron microscope image of the cross-sectional morphology of the 52-μm-thick Bi2Te3 thermoelectric thick film prepared by the method of the present embodiment, and it can be seen from the figure that the thickness of the Bi2Te3 thermoelectric thick film is uniform and the structure is dense. The power factor of the 52-μm-thick Bi2Te3 thermoelectric thick film was measured to be 26.15 μW·cm -1 ·K -2 .

[0073] Example 5

[0074] The present embodiment provides a method for rapidly preparing a high-performance thermoelectric thick film, which is a 106-μm-thick n-type Bi2Te3 thermoelectric thick film.

[0075] The preparation method of the n-type Bi2Te3 thermoelectric thick film comprises the following steps:

[0076] (1) A 150-μm-deep groove was made on a 400-μm-thick alumina flat plate as a pre-pressing mold for the thermoelectric powder, and the pre-pressing mold was cleaned with ethanol;

[0077] Bi2Te3 thermoelectric powder with particle size less than 70 μm is screened by a screen, 464 mg of the thermoelectric powder is weighed and placed in a groove of a pre-pressing mold, and the thermoelectric powder is just filled and leveled in the groove with a depth of 150 μm; a pressure head with a diameter of 20 mm is used to apply a pressure of 100 MPa on the leveled thermoelectric powder, and a thermoelectric film wafer with a diameter of 20 mm is pressed out;

[0078] (2) The thermoelectric film wafer of step (1) is transferred to a high-pressure tablet mold made of high-hardness chromium steel which can just place a wafer with a diameter of 20 mm, and a tablet press is used to apply a pressure of 800 MPa and keep the pressure for 1 min to realize densification of the thermoelectric thick film, and a densified thermoelectric thick film is obtained;

[0079] (3) The densified thermoelectric thick film of step (2) is transferred to a quartz tube furnace, vacuum is first extracted, and then Ar gas is introduced, the flow rate of the Ar gas is 200 sccm, the Ar gas pressure is 1 atm, and heating, annealing and sintering are performed, the annealing and sintering temperature is 450 ℃, and the annealing time is 1 h, and finally the n-type Bi2Te3 thermoelectric thick film with a thickness of 106 μm and high thermoelectric performance is obtained.

[0080] As shown in Figure 6 FIG. 6 is a scanning electron microscope image of a cross-sectional morphology of the 106 μm-thick Bi2Te3 thermoelectric thick film prepared by the method of the present embodiment, and it can be seen from the figure that the thickness of the Bi2Te3 thermoelectric thick film is uniform and the structure is dense. The power factor of the 106 μm-thick Bi2Te3 thermoelectric thick film is measured to be 26.23 μW·cm -1 ·K -2 .

[0081] Example 6

[0082] The present embodiment provides a method for rapidly preparing a high-performance thermoelectric thick film, and the thermoelectric thick film is an n-type Bi2Te3 thermoelectric thick film with a thickness of 175 μm.

[0083] The preparation method of the n-type Bi2Te3 thermoelectric thick film comprises the following steps:

[0084] (1) A 250 μm-deep groove is made on a 400 μm-thick alumina flat plate as a pre-pressing mold for thermoelectric powder, and the pre-pressing mold is cleaned with ethanol;

[0085] Bi2Te3 thermoelectric powder with particle size less than 70 μm is screened by a screen, 765 mg of the thermoelectric powder is weighed and placed in the groove of the pre-pressing mold, and the thermoelectric powder is just filled and leveled in the groove with a depth of 250 μm; a pressure head with a diameter of 20 mm is used to apply a pressure of 150 MPa on the leveled thermoelectric powder, and a thermoelectric film wafer with a diameter of 20 mm is pressed out;

[0086] (2) The hot-electric film wafer of step (1) is transferred to a high-pressure tabletting die made of high-hardness chromium steel which can just place a 20mm diameter wafer, and a tabletting machine is used to apply a pressure of 800MPa for 1min to realize the densification of the hot-electric thick film, and a densified hot-electric thick film is obtained.

[0087] (3) The densified hot-electric thick film of step (2) is transferred to a quartz tube furnace, vacuum is first extracted, then Ar gas is introduced, the Ar gas flow rate is 200sccm, the Ar gas pressure is 1atm, and heating annealing sintering is performed, the annealing sintering temperature is 450℃, and the annealing time is 1h, and finally the 175μm thick n-type Bi2Te3 hot-electric thick film with high thermoelectric performance is obtained.

[0088] As shown in Figure 7 Figure 2 shows the scanning electron microscope image of the cross-sectional morphology of the 175μm thick Bi2Te3 hot-electric thick film prepared by the method of the present embodiment, and it can be seen from the figure that the thickness of the Bi2Te3 hot-electric thick film is uniform and the structure is dense. The power factor of the 175μm thick Bi2Te3 hot-electric thick film is measured to be 26.09μW·cm -1 ·K -2 .

[0089] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for rapidly fabricating a thermoelectric thick film, characterized by, The application discloses a method for rapidly preparing a thermoelectric thick film by powder metallurgy. The method comprises the following steps: (1) pre-pressing: flattening the thermoelectric powder in a pre-pressing mold, and then pressing the thermoelectric powder to obtain a sheet-shaped thermoelectric thick film under a pressure of 100-400 MPa; (2) cold-pressing the sheet-shaped thermoelectric thick film obtained in step (1) under high pressure, and keeping the pressure for 1-10 min to obtain a densified thermoelectric thick film; (3) annealing and sintering the densified thermoelectric thick film obtained in step (2) to obtain the thermoelectric thick film, wherein the thickness of the thermoelectric thick film is less than 200 μm; In step (1), the particle size of the thermoelectric powder is less than the thickness of the sheet-shaped thermoelectric thick film; The thermoelectric powder is a Bi2Te3-based thermoelectric powder; The Bi2Te3-based thermoelectric powder is Bi2Te3or Bi 0.5 Sb 1.5 Te3.

2. The method of claim 1, wherein In step (1), the pre-pressing mold is made of a hard material.

3. The method of claim 1, wherein the thick film is prepared by a screen printing method. In step (2), the pressure for cold-pressing is 400-1200 MPa.

4. The method of claim 1, wherein the thick film is prepared in less than 5 minutes. In step (3), the sintering is carried out in an argon atmosphere under one atmosphere. The annealing and sintering temperature is 300-500 ℃, and the annealing time is 0.5-2 h.

5. The thermoelectric thick film prepared by the method according to any one of claims 1-4.

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