High-entropy thermoelectric interface material, ge te-based thermoelectric composite material containing the interface layer and preparation method and application thereof

Abstract

The application provides a high-entropy thermoelectric interface material, a GeTe-based thermoelectric composite material containing the interface layer, and a preparation method and application thereof. The chemical general formula of the high-entropy thermoelectric interface material is FeaMobVcNbdWe, wherein a=40-70; b=10-40; c=5-40; d=5-10; e=5-30, and a, b, c, d and e respectively represent the atomic percentage of each element. The thermoelectric interface material can be well adapted to a GeTe-based thermoelectric conversion material. The GeTe-based thermoelectric composite material containing the interface layer can still maintain excellent performance after serving at a high temperature of 500 DEG C for 168 hours while obtaining ultrahigh initial shear strength and extremely low contact resistivity, and has excellent interface bonding strength, extremely low contact resistance, excellent high-temperature stability and good thermal expansion matching, thereby effectively solving the problems of weak bonding force of a traditional barrier layer and easy failure at high temperature.

Description

Technical Field

[0001] This invention relates to thermoelectric device technology, and more particularly to a high-entropy thermoelectric interface material, a GeTe-based thermoelectric composite material containing the interface layer, and its preparation method and application. Background Technology

[0002] Due to the excessive consumption of fossil fuels and the resulting environmental pollution, the global demand for renewable resources and energy conversion efficiency is constantly growing. Thermoelectric materials are functional materials that utilize the Seebeck and Peltier effects to achieve the interconversion of thermal and electrical energy. Among them, (Ge... 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 Thermoelectric materials possess excellent thermoelectric properties and are among the most promising medium- and high-temperature thermoelectric materials in recent years. However, the assembly and reliability of thermoelectric devices are the biggest challenges to their practical application, with the contact interface between the thermoelectric material and the electrode being particularly critical.

[0003] Currently, thermoelectric devices are typically assembled using brazing or soldering. Most thermoelectric materials exhibit poor weldability due to their semiconductor properties; therefore, a metallization layer is required between the thermoelectric material and the electrode to achieve a reliable bond. Numerous single-metal barrier layers have been studied, but their interfacial reactions limit the improvement of bond strength, resulting in weak interfacial bonding. In relatively high-temperature operating environments, poor interfacial bonding strength can further lead to mechanical failure of the device.

[0004] To address the aforementioned issues, the industry has attempted to develop multi-element alloy interface materials, but existing solutions have not yet fully considered interface reaction regulation, thermal expansion matching, and long-term service stability, and still cannot fully meet the packaging requirements of high-performance thermoelectric devices. Summary of the Invention

[0005] The purpose of this invention is to address the problems of weak interfacial bonding and high-temperature failure of existing GeTe-based thermoelectric devices with single-metal or simple alloy interfacial layers, which fail to meet the requirements for long-term reliable operation. This invention proposes a high-entropy thermoelectric interface material that is well-compatible with GeTe-based thermoelectric conversion materials. The GeTe-based thermoelectric composite material containing this interface layer achieves ultra-high initial shear strength and extremely low contact resistivity, while maintaining excellent performance after 168 hours of service at 500°C. It combines excellent interfacial bonding strength, extremely low contact resistance, superior high-temperature stability, and good thermal expansion matching, effectively solving the problems of weak bonding and high-temperature failure of traditional barrier layers.

[0006] It should be noted that, in this invention, unless otherwise specified, the specific meaning of "comprising" in relation to composition and description includes both open-ended meanings such as "comprising," "including," etc., and closed-ended meanings such as "composed of," "consisting of," etc., and similar meanings.

[0007] To achieve the above objectives, the technical solution adopted by this invention is: a high-entropy thermoelectric interface material with the general chemical formula: Fe a Mo b V c Nb d W e Where a = 40–70; b = 10–40; c = 5–40; d = 5–10; e = 5–30, and a, b, c, d, and e represent the atomic percentages of each element.

[0008] Furthermore, the general chemical formula of the high-entropy thermoelectric interface material is: Fe a Mo b V c Nb d W e a = 60–70; b = 10–20; c = 5–10; d = 5–10; e = 5–10, where a, b, c, d, and e represent the atomic percentages of each element. A typical ratio is Fe. 60 Mo 15 V 10 Nb5W 10 .

[0009] Another objective of this invention discloses a method for preparing a high-entropy thermoelectric interface material, comprising the following steps: mixing the raw materials according to a specified ratio, and ball milling under inert gas protection to obtain alloy powder, which is the high-entropy thermoelectric interface material. That is, the high-entropy thermoelectric interface material of this invention is prepared by mechanical alloying.

[0010] Furthermore, the ball milling time is 10-15 hours.

[0011] Another objective of this invention is to disclose the application of a high-entropy thermoelectric interface material in the fabrication of thermoelectric devices.

[0012] Another object of the present invention discloses a GeTe-based thermoelectric composite material containing a thermoelectric interface material, comprising a thermoelectric conversion material (TEcM) and the high-entropy thermoelectric interface material (TEiM) composited to at least a portion of the surface of the thermoelectric conversion material.

[0013] Furthermore, the thermoelectric conversion material is composite with a thermoelectric interface material on one or both sides, and the single-leg thermoelectric device is preferably a double-sided composite structure.

[0014] Furthermore, the thermoelectric conversion material is a p-type thermoelectric conversion material.

[0015] Furthermore, the thermoelectric conversion material comprises the following general chemical formula (Ge x Sb y Bi z Te w ) 0.96 (CdTe) 0.04 Where x = 0.5~1; y = 0.01~0.1; z = 0.01~0.1; w = 0.5~1, and x, y, z, and w represent the atomic percentage of each element.

[0016] Furthermore, the thermoelectric conversion material comprises the following general chemical formula (Ge x Sb y Bi z Te w ) 0.96 (CdTe) 0.04 Where x = 0.8~1; y = 0.01~0.03; z = 0.05~0.07; w = 0.8~1, and x, y, z, and w represent the atomic percentage of each element.

[0017] Furthermore, the typical formulation of the thermoelectric conversion material is P-type (Ge). 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 .

[0018] Furthermore, the thickness of the thermoelectric conversion material is 4–6 mm.

[0019] Furthermore, the thickness of the thermoelectric interface material layer is 0.2–0.4 mm.

[0020] Furthermore, the interface of the GeTe-based thermoelectric composite material containing the thermoelectric interface material not only possesses excellent comprehensive properties after synthesis, with a shear strength >10MPa and a contact resistivity greater than 1.8657μΩ·cm, but also exhibits excellent overall performance. 2 Furthermore, after 7 days of service at 500℃, it still exhibits high shear strength (>20 MPa) and contact resistivity (>4.7439 μΩ·cm). 2 .

[0021] Furthermore, the interface of the GeTe-based thermoelectric composite material containing the thermoelectric interface material not only possesses excellent comprehensive properties after synthesis, with a shear strength of 25–32.33 MPa and a contact resistivity of 1.8657–3 μΩ·cm, but also exhibits excellent overall performance. 2Furthermore, after 7 days of service at 500℃, it still maintains a high shear strength of 20–31.67 MPa and a contact resistivity of 4.7439–7 μΩ·cm. 2 .

[0022] Furthermore, the preparation method of the thermoelectric conversion material includes: mixing the raw materials according to the formula, ball milling under inert gas protection to obtain alloy powder, which is the thermoelectric interface material.

[0023] Furthermore, the preparation method of the thermoelectric conversion material includes: mixing the raw materials according to the specified ratio and sealing them in a vacuum quartz tube; gradually heating the sealed tube from room temperature to 1223–1423 K to obtain a uniform melt; and then rapidly quenching it in cold water. The quenched ingot is annealed at 873–973 K for 3 days to ensure compositional uniformity. Finally, the ingot is ground into a fine powder.

[0024] Another objective of this invention discloses a method for preparing a GeTe-based thermoelectric composite material containing a thermoelectric interface material, comprising: placing the thermoelectric interface material onto at least a portion of the surface of a thermoelectric conversion material, and subjecting it to sintering treatment to obtain the GeTe-based thermoelectric composite material containing the thermoelectric interface material.

[0025] Furthermore, the sintering process is spark plasma sintering.

[0026] Furthermore, the temperature of the discharge plasma sintering is 400–600°C, preferably 500°C.

[0027] Furthermore, the discharge plasma sintering time is 10–15 min.

[0028] Furthermore, the axial pressure of the discharge plasma sintering is 40-100 MPa, preferably 65 MPa.

[0029] Furthermore, the heating rate to the discharge plasma sintering temperature is 50–100 °C / min.

[0030] Furthermore, the raw materials used to prepare thermoelectric conversion materials and thermoelectric interface materials are all elemental raw materials.

[0031] Furthermore, the particle size of each elemental raw material is 200-400 mesh, and the purity is greater than 98%.

[0032] Furthermore, the specific raw materials of each element are as follows:

[0033] Fe powder, 300 mesh, 99.9% purity.

[0034] Mo powder, 250 mesh, 99% purity.

[0035] V-powder, 250 mesh, 99% purity.

[0036] Nitrogen powder, 250 mesh, 99% purity.

[0037] W powder, 200 mesh, 98% purity.

[0038] Ge particles, φ3mm, purity 99.95%.

[0039] Sb particles, φ3mm, purity 99.95%.

[0040] Te particles, φ3mm, purity 99.995%.

[0041] Bi particles, φ3mm, purity 99.995%.

[0042] Cd particles, φ2mm, purity 99.999%.

[0043] Furthermore, when preparing thermoelectric conversion materials and thermoelectric interface materials, the inert gas includes, but is not limited to, at least one of nitrogen (N2), helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe).

[0044] Another objective of this invention is to disclose the application of a GeTe-based thermoelectric composite material containing a thermoelectric interface material in the field of thermoelectric devices.

[0045] Furthermore, the thermoelectric device is a single-leg thermoelectric device.

[0046] The high-entropy thermoelectric interface material, the GeTe-based thermoelectric composite material containing the interface layer, the preparation method and application of the present invention have the following advantages compared with the prior art:

[0047] 1) The high-entropy thermoelectric interface material (Fe) provided by this invention a Mo b V c Nb d W e ) and P-type (Ge x Sb y Bi z Te w ) 0.96 (CdTe) 0.04 When thermoelectric conversion materials (TEcMs) are composited, they possess excellent interfacial properties even in their synthesized state. For example, Fe... 60 Mo 15 V 10 Nb5W 10 / (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04The thermoelectric composite material exhibits a shear strength as high as 32.33 MPa, while maintaining an extremely low contact resistivity of 1.8657 μΩ·cm. 2 It significantly outperforms industry standards (shear strength > 10 MPa, contact resistivity < 10 μΩ·cm). 2 ).

[0048] 2) The GeTe-based thermoelectric composite material containing thermoelectric interface material of the present invention has excellent thermal stability and anti-aging ability, which can meet the requirements for long-term reliable operation of medium and high temperature thermoelectric devices. For example, Fe 60 Mo 15 V 10 Nb5W 10 / (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 After 168 hours (7 days) of service at 500 ℃, the thermoelectric composite material still maintains high interfacial bonding strength (31.67 MPa) and low contact resistivity (4.7439 μΩ·cm). 2 The decrease in shear strength is minimal.

[0049] 3) The thermoelectric conversion material and the high-entropy thermoelectric interface material selected in the GeTe-based thermoelectric composite material containing thermoelectric interface material of this invention have similar coefficients of thermal expansion, which effectively reduces the interface thermal stress under high temperature conditions, avoids crack initiation and propagation, and thus ensures the mechanical integrity of the interface and long-term service reliability.

[0050] 4) This invention uses spark plasma sintering (SPS) technology, which can achieve rapid densification of interface materials and thermoelectric materials under conditions of 400-600 ℃, 10-15 min, and 40-100 MPa. The process has a short cycle and strong controllability, which is conducive to large-scale production and practical application.

[0051] 5) This invention effectively solves the problems of weak bonding strength and easy failure at high temperatures in traditional single-metal barrier layers, enabling thermoelectric devices to still meet the requirements of shear strength > 20 MPa and contact resistivity < 10 μΩ·cm in high-temperature service environments. 2 This meets industry requirements and provides a reliable interface solution for the engineering application of GeTe-based thermoelectric devices.

[0052] In summary, the GeTe-based thermoelectric composite material containing thermoelectric interface material of the present invention has good application prospects and large-scale promotion potential in the field of thermoelectric devices. Attached Figure Description

[0053] Figure 1 For Fe 60 Mo15 V 10 Nb5W 10 SEM image of / TEcM thermoelectric composite material;

[0054] Figure 2 773K annealed for 7 days, Fe 60 Mo 15 V 10 Nb5W 10 SEM image of / TEcM thermoelectric composite material;

[0055] Figure 3 For Fe 60 Mo 15 V 10 Nb5W 10 Shear strength diagram of / TEcM thermoelectric composite material;

[0056] Figure 4 For Fe 60 Mo 15 V 10 Nb5W 10 Shear strength diagram of / TEcM thermoelectric composite material after annealing at 500℃ for 7 days;

[0057] Figure 5 For Fe 60 Mo 15 V 10 Nb5W 10 / TEcM thermoelectric composite material contact resistance diagram;

[0058] Figure 6 For Fe 60 Mo 15 V 10 Nb5W 10 Contact resistance diagram of / TEcM thermoelectric composite material after annealing at 500℃ for 7 days. Detailed Implementation

[0059] The present invention will be further described below with reference to embodiments. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0060] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0061] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0062] In this specification, the numerical range indicated by "above" or "below" refers to the numerical range that includes the stated number.

[0063] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0064] In this specification, the terms "optional" or "optional" are used to indicate the use or omission of certain substances, components, procedures, application conditions, etc.

[0065] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be 15-25℃.

[0066] Unless otherwise specified, all reagents or instruments used in this instruction manual are commercially available products.

[0067] Example 1

[0068] This embodiment discloses a GeTe-based thermoelectric composite material Fe containing a thermoelectric interface material. 60 Mo 15 V 10 Nb5W 10 / (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 This includes thermoelectric conversion materials (TEcM) and high-entropy thermoelectric interface materials (TEiM) composited to at least a portion of the surface of thermoelectric conversion materials. The chemical formula of TEcM is as follows: (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 The chemical formula of TEiM is as follows: Fe 60 Mo 15 V 10 Nb5W 10 .

[0069] The preparation method of the GeTe-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows:

[0070] Preparation of TEcM: The elemental raw materials were weighed according to the designed proportions and sealed in a vacuum quartz tube. The sealed tube was gradually heated from room temperature to 1223 K to obtain a homogeneous melt, followed by rapid quenching in cold water. The quenched ingot was annealed at 873 K for 3 days to ensure compositional homogeneity. Finally, the ingot was ground into a fine powder.

[0071] Preparation of TEiM: Weigh each elemental raw material according to the design ratio, and obtain alloy powder by high-energy ball milling (tungsten carbide balls with a diameter of 5 mm) for 10-11 hours under argon protection using mechanical alloying method.

[0072] GeTe-based thermoelectric composites containing thermoelectric interface materials Fe 60 Mo 15 V 10 Nb5W 10 / (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 Preparation: First, sample loading was performed, specifically by placing TEcM powder in a graphite mold, specifically between the upper and lower TEiM powders, forming a sandwich-like structure. Then, spark plasma sintering was performed. The TEiM powder and TEcM powder formed a TEiM / TEcM contact interface through spark plasma sintering at 500℃ for 15 min and 65 MPa axial pressure. The heating rate during sintering was 100℃*min. -1 The thicknesses of the TEcM block and the TEiM layer are designed to be 4 mm and 0.3 mm, respectively.

[0073] Table 1 Fe in Comparative Example 1 60 Mo 15 V 10 Ta5W 10 / TecM's performance indicators

[0074]

[0075] Example 2

[0076] This embodiment discloses a GeTe-based thermoelectric composite material Fe containing a thermoelectric interface material. 60 Mo 10 V 15 Nb5W 10 / (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 This includes thermoelectric conversion materials (TEcM) and high-entropy thermoelectric interface materials (TEiM) composited to at least a portion of the surface of thermoelectric conversion materials. The chemical formula of TEcM is as follows: (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 The chemical formula of TEiM is as follows: Fe 60 Mo10 V 15 Nb5W 10 .

[0077] The preparation method of the GeTe-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows:

[0078] Preparation of TEcM: The elemental raw materials were weighed according to the designed proportions and sealed in a vacuum quartz tube. The sealed tube was gradually heated from room temperature to 1223 K to obtain a homogeneous melt, followed by rapid quenching in cold water. The quenched ingot was annealed at 873 K for 3 days to ensure compositional homogeneity. Finally, the ingot was ground into a fine powder.

[0079] Preparation of TEiM: Weigh each elemental raw material according to the design ratio, and obtain alloy powder by high-energy ball milling (tungsten carbide balls with a diameter of 5 mm) for 10-11 hours under argon protection using mechanical alloying method.

[0080] GeTe-based thermoelectric composites containing thermoelectric interface materials Fe 60 Mo 10 V 15 Nb5W 10 / (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 Preparation: First, sample loading was performed, specifically by placing TEcM powder in a graphite mold, specifically between the upper and lower TEiM powders, forming a sandwich-like structure. Then, spark plasma sintering was performed. The TEiM powder and TEcM powder formed a TEiM / TEcM contact interface through spark plasma sintering at 500℃ for 15 min and 65 MPa axial pressure. The heating rate during sintering was 100℃*min. -1 The thicknesses of the TEcM block and the TEiM layer are designed to be 4 mm and 0.3 mm, respectively.

[0081] Table 2 Fe in Example 2 60 Mo 10 V 15 Nb5W 10 / TecM's performance indicators

[0082]

[0083] Example 3

[0084] This embodiment discloses a GeTe-based thermoelectric composite material Fe containing a thermoelectric interface material. 60 Mo 15 V 10 Nb 10 W5 / (Ge0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 This includes thermoelectric conversion materials (TEcM) and high-entropy thermoelectric interface materials (TEiM) composited to at least a portion of the surface of thermoelectric conversion materials. The chemical formula of TEcM is as follows: (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 The chemical formula of TEiM is as follows: Fe 60 Mo 15 V 10 Nb 10 W5.

[0085] The preparation method of the GeTe-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows:

[0086] Preparation of TEcM: The elemental raw materials were weighed according to the designed proportions and sealed in a vacuum quartz tube. The sealed tube was gradually heated from room temperature to 1223 K to obtain a homogeneous melt, followed by rapid quenching in cold water. The quenched ingot was annealed at 873 K for 3 days to ensure compositional homogeneity. Finally, the ingot was ground into a fine powder.

[0087] Preparation of TEiM: Weigh each elemental raw material according to the design ratio, and obtain alloy powder by high-energy ball milling (tungsten carbide balls with a diameter of 5 mm) for 10-11 hours under argon protection using mechanical alloying method.

[0088] GeTe-based thermoelectric composites containing thermoelectric interface materials Fe 60 Mo 15 V 10 Nb 10 W5 / (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 Preparation: First, sample loading was performed, specifically by placing TEcM powder in a graphite mold, specifically between the upper and lower TEiM powders, forming a sandwich-like structure. Then, spark plasma sintering was performed. The TEiM powder and TEcM powder formed a TEiM / TEcM contact interface through spark plasma sintering at 500℃ for 15 min and 65 MPa axial pressure. The heating rate during sintering was 100℃*min. -1 The thicknesses of the TEcM block and the TEiM layer are designed to be 4 mm and 0.3 mm, respectively.

[0089] Table 3 Fe in Example 360 Mo 15 V 10 Nb 10 Performance metrics of W5 / TecM

[0090]

[0091] Comparative Example 1

[0092] This comparative example discloses a composite material Fe 60 Mo 15 V 10 Ta5W 10 / (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 The chemical formula of TEcM is as follows: (Ge 0.92 Sb 0.02 Bi 0.06 Te) 0.96 (CdTe) 0.04 The chemical formula of TEiM is as follows: Fe 60 Mo 15 V 10 Ta5W 10 Its preparation method is the same as that in Example 1.

[0093] The composite materials of Example 1 and Comparative Example 1 were tested respectively. The test methods and results are as follows:

[0094] The diffusion barrier, shear strength, and contact resistivity of the high-entropy thermoelectric interface material (TEiM) and the thermoelectric conversion material (TEcM) selected in the examples are all at ideal levels. Figure 1 As shown, the interface in Example 1 shows good bonding and no diffusion. Figure 2 As shown, after annealing at 773K for 7 days, the interface bonding in the example remained good, with no diffusion. Figure 3 As shown, the bonding strength between Example 1 and TEcM is 32.33 MPa, while the industry standard is >10 MPa, indicating that it is significantly higher than the industry standard. Figure 4 As shown, after annealing at 773K for 7 days, the bonding strength between Example 1 and TEcM was 31.67 MPa, which is significantly higher than the industry standard of >10 MPa, indicating almost no attenuation. Figure 5 As shown, the contact resistivity between Example 1 and TecM is extremely low, at 1.86 µΩ·cm. 2 It is far below the industry standard (<10 µΩ·cm) 2 ).like Figure 6As shown, after annealing at 773K for 7 days, the contact resistivity between Example 1 and TecM remained extremely low at 4.74 µΩ·cm. 2 It is far below the industry standard (<10 µΩ·cm) 2 It exhibits high stability. Table 1 shows the Fe of Comparative Example 1. 60 Mo 15 V 10 Ta5W 10 The performance indicators of / TecM showed a slight decrease compared to Example 1, but still exceeded industry standards. Table 2 shows the Fe performance of Example 2. 60 Mo 10 V 15 Nb5W 10 The performance indicators of / TecM are all far higher than the industry standards. Table 3 shows the Fe of Example 3. 60 Mo 10 V 15 Nb5W 10 / TecM's performance indicators are all far higher than industry standards.

[0095] Shear strength and contact resistivity tests are conducted in accordance with the general standards of this industry. For detailed test procedures, please refer to the literature (Acta Materialia 226 (2022) 117616) Section 2.2 (the third paragraph on the second page of the literature report).

[0096] A vacuum-sealed tube was used to simulate a high-temperature environment for heat treatment of the material. The interface was placed in a quartz tube, and a vacuum was drawn until the vacuum level reached 10. -3 After Pa, the quartz tube was sealed with a flame gun, and then placed in a muffle furnace. The temperature was increased to 500°C at a rate of 7°C / min, and held for different times to simulate the actual service environment of the device. Figure 2 As shown in Figures 3, 4, 5, and 6, based on the slopes of the interfacial shear strength and contact resistivity changes with time, it can be seen that under different service times at 500℃, Fe... 60 Mo 15 V 10 Nb5W 10 The shear strength of the / TEcM interface shows a very small trend over time, indicating that this high-entropy thermoelectric interface material is most beneficial for improving the thermal stability of the interface. After 7 days of service, Fe... 60 Mo 15 V 10 Nb5W 10 The shear strength at the / TEcM interface only decreased from 32.33 MPa to 31.67 MPa, both of which are far greater than the qualified interface shear strength of 10 MPa. Fe 60 Mo 15 V 10Nb5W 10 The / TEcM interface exhibits extremely low and stable contact resistivity. After 7 days of service at 500℃, the contact interface still meets the requirements of bonding strength >10 MPa and contact resistivity <10 μΩ*cm. 2 This meets industry requirements and offers competitive interface stability performance within the current industry.

[0097] The reliability of thermoelectric devices largely depends on the interfacial contact between the thermoelectric material and the electrodes. In one embodiment, the present invention provides a high-entropy alloy, and the thermoelectric device prepared using this type of high-entropy alloy exhibits an interfacial shear strength >10 MPa and extremely low contact resistivity. Furthermore, after 7 days of service at 500°C, the shear strength of the contact interface is >20 MPa, and the contact resistivity remains extremely low.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-entropy thermoelectric interface material, characterized in that, The general chemical formula is: Fe a Mo b V c Nb d W e Where a = 40–70; b = 10–40; c = 5–40; d = 5–10; e = 5–30, and a, b, c, d, and e represent the atomic percentages of each element.

2. A method for preparing the high-entropy thermoelectric interface material according to claim 1, characterized in that, The process includes the following steps: mixing the raw materials according to the specified ratio, and ball milling them under inert gas protection to obtain alloy powder, which is the high-entropy thermoelectric interface material.

3. The application of the high-entropy thermoelectric interface material of claim 1 in the field of thermoelectric device fabrication.

4. A GeTe-based thermoelectric composite material containing a thermoelectric interface material, characterized in that, The high-entropy thermoelectric interface material of claim 1 includes thermoelectric conversion materials and composites to at least a portion of the surface of thermoelectric conversion materials.

5. The GeTe-based thermoelectric composite material containing a thermoelectric interface material according to claim 4, characterized in that, The thermoelectric conversion material is a p-type thermoelectric conversion material with the general chemical formula (Ge). x Sb y Bi z Te w ) 0.96 (CdTe) 0.04 Where x = 0.5~1; y = 0.01~0.1; z = 0.01~0.1; w = 0.5~1, and x, y, z, and w represent the atomic percentage of each element.

6. The GeTe-based thermoelectric composite material containing a thermoelectric interface material according to claim 4, characterized in that, The thickness of the thermoelectric conversion material is 4-6 mm; And / or, the thickness of the thermoelectric interface material layer is 0.2 to 0.4 mm.

7. A method for preparing a GeTe-based thermoelectric composite material containing a thermoelectric interface material as described in any one of claims 4-6, characterized in that, include: A thermoelectric interface material is placed on at least a portion of the surface of a thermoelectric conversion material and then sintered to obtain the GeTe-based thermoelectric composite material containing the thermoelectric interface material.

8. The method for preparing the GeTe-based thermoelectric composite material containing the thermoelectric interface material according to claim 7, characterized in that, The sintering process is spark plasma sintering, and the temperature of spark plasma sintering is 400-600℃. And / or, the time for the discharge plasma sintering is 10 to 15 minutes; And / or, the axial pressure of the discharge plasma sintering is 40-100 MPa; And / or, the heating rate to the discharge plasma sintering temperature is 50–100 °C / min.

9. The application of a GeTe-based thermoelectric composite material containing a thermoelectric interface material as described in any one of claims 4-6 in the field of thermoelectric devices.

10. The application according to claim 9, characterized in that, The thermoelectric device is a single-leg thermoelectric device.

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