Thermoelectric interface material, zrcosb-based thermoelectric composite material containing the interface layer and preparation method and application thereof

Abstract

The application provides a thermoelectric interface material, a ZrCoSb-based thermoelectric composite material containing the interface layer, and a preparation method and application thereof. a V b Nb c Ta d W e , wherein a=10-30; b=10-40; c=10-40; d=10-40; e=10-40, and a, b, c, d and e respectively represent the atomic percentage of each element. The thermoelectric interface material is prepared by a mechanical alloying method, and is combined with Zr h Co i Sb j HfkSn l The thermoelectric conversion material is combined by hot-pressing sintering to form a layered interface structure. After the thermoelectric interface material is combined with the thermoelectric conversion material, the interface shear strength is as high as 73.66 MPa, the contact resistivity is extremely low, the shear strength is still maintained above 50 MPa after 7 days of high-temperature service at 650 DEG C, has excellent bonding strength, electrical conductivity and high-temperature stability, and can be widely applied in the fields of single-leg thermoelectric devices and the like.

Description

Technical Field

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

[0002] The excessive consumption of fossil fuels and the resulting environmental pollution have made the global demand for renewable energy development and improved energy conversion efficiency increasingly urgent. Thermoelectric materials, as functional materials capable of directly converting heat energy into electrical energy using the Seebeck and Peltier effects, have broad application prospects in waste heat recovery and solid-state refrigeration. Among them, Zr... 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 Due to their excellent thermoelectric properties, thermoelectric materials have become one of the most promising high-temperature thermoelectric materials in recent years.

[0003] However, thermoelectric devices still face many challenges in moving from the laboratory to practical applications. Their assembly process and service reliability are particularly critical, and the contact interface characteristics between thermoelectric materials and electrodes are one of the core factors affecting device reliability.

[0004] Currently, thermoelectric devices are typically assembled using brazing or soldering. However, most thermoelectric materials exhibit semiconductor properties, resulting in poor weldability. Therefore, a metallization layer is usually required between the thermoelectric material and the electrode to achieve a reliable electrical and mechanical connection. Existing research has explored various single-metal barrier layers, but due to difficulties in controlling interfacial reactions, insufficient bonding strength is a common problem. Under high-temperature service conditions, weak interfacial bonding strength can easily lead to mechanical failure of the device, severely affecting its long-term stability and service life.

[0005] In summary, developing a novel thermoelectric interface material that combines high bonding strength, low contact resistivity, and excellent high-temperature stability is of great significance for improving the overall performance and reliability of thermoelectric devices. Summary of the Invention

[0006] The purpose of this invention is to address the problems of weak interfacial bonding strength between thermoelectric materials and electrodes in traditional thermoelectric devices, which easily leads to mechanical failure under high-temperature operating environments, and high contact resistivity, thus failing to meet the reliability requirements of the devices. This invention proposes a thermoelectric interface material that, when combined with ZrCoSb thermoelectric material, possesses both extremely high interfacial bonding strength (shear strength up to 73.66 MPa) and extremely low contact resistivity. Furthermore, it maintains excellent interfacial stability (shear strength > 50 MPa) even after long-term service at 650°C for 7 days.

[0007] 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.

[0008] To achieve the above objectives, the technical solution adopted by this invention is: a thermoelectric interface material with the general chemical formula: Cr a V b Nb c Ta d W e Where a = 10–30; b = 10–40; c = 10–40; d = 10–40; e = 10–40, and a, b, c, d, and e represent the atomic percentages of each element.

[0009] Furthermore, the general chemical formula of the thermoelectric interface material is: Cr a V b Nb c Ta d W e Where a = 15–25; b = 15–25; c = 15–25; d = 15–25; e = 15–25, and a, b, c, d, and e represent the atomic percentages of each element.

[0010] Another objective of this invention discloses a method for preparing a 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 thermoelectric interface material. That is, the thermoelectric interface material of this invention is prepared by mechanical alloying.

[0011] Furthermore, the ball milling time is 10 to 15 hours.

[0012] Another objective of this invention is to disclose the application of a thermoelectric interface material in the fabrication of thermoelectric devices.

[0013] Another object of the present invention discloses a ZrCoSb-based thermoelectric composite material containing a thermoelectric interface material, comprising a thermoelectric conversion material (TEcM) and the thermoelectric interface material (TEiM) composited to at least a portion of the surface of the thermoelectric conversion material.

[0014] 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.

[0015] Furthermore, the thermoelectric conversion material is a p-type thermoelectric conversion material.

[0016] Furthermore, the thermoelectric conversion material comprises the following general chemical formula Zrh Co i Sb j HfkSn l h = 0.1~1; i = 0.8~1.3; j = 0.1~1; k = 0.1~0.5; l = 0.1~0.5, where h, i, j, k, and l represent the atomic percentage of each element.

[0017] Furthermore, the thermoelectric conversion material comprises the following general chemical formula Zr h Co i Sb j HfkSn l h = 0.7~1; i = 1~1.3; j = 0.7~1; k = 0.1~0.3; l = 0.1~0.3, where h, i, j, k, and l represent the atomic percentage of each element.

[0018] Furthermore, the typical formulation of the thermoelectric conversion material is P-type Zr. 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 .

[0019] Furthermore, the thickness of the thermoelectric conversion material is 4–6 mm.

[0020] Furthermore, the thickness of the thermoelectric interface material layer is 0.2–0.4 mm.

[0021] Furthermore, the ZrCoSb-based thermoelectric composite material containing thermoelectric interface material exhibits excellent comprehensive properties at the interface after synthesis, with an interface shear strength >10MPa and a contact resistivity greater than 0.792µΩ•cm. 2 Furthermore, after 7 days of service at 650℃, it still exhibits high shear strength (>20 MPa) and contact resistivity (>3.17 µΩ•cm). 2 .

[0022] Furthermore, the ZrCoSb-based thermoelectric composite material containing thermoelectric interface material exhibits excellent comprehensive properties at its interface after synthesis, with a shear strength of 65–73.66 MPa and a contact resistivity of 0.792–1.5 µΩ•cm. 2 Furthermore, after 7 days of service at 650℃, it still maintains a high shear strength of 45–50 MPa and a contact resistivity of 3.17–5 µΩ•cm. 2 .

[0023] Furthermore, the preparation method of the thermoelectric conversion material includes: mixing the raw materials according to the formula and ball milling them into powder under the protection of inert gas.

[0024] Furthermore, the preparation method of the thermoelectric conversion material includes: mixing the raw materials according to the formula and ball milling them into powder for 10 to 15 hours under inert gas protection.

[0025] Furthermore, the rate of heating to the sintering temperature during the preparation of the thermoelectric conversion material is 10–100 °C·min. -1 .

[0026] Another objective of this invention discloses a method for preparing a ZrCoSb-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 ZrCoSb-based thermoelectric composite material containing the thermoelectric interface material.

[0027] Furthermore, the sintering process is hot pressing sintering.

[0028] Furthermore, the hot pressing sintering temperature is 900–1200°C, preferably 1100°C.

[0029] Furthermore, the hot pressing sintering time is 50–80 min.

[0030] Furthermore, the axial pressure of the hot pressing sintering is 40-100 MPa, preferably 65 MPa.

[0031] Furthermore, the heating rate to the hot-pressing sintering temperature is 10–100 °C / min.

[0032] Furthermore, the raw materials used to prepare thermoelectric conversion materials and thermoelectric interface materials are all elemental raw materials.

[0033] Furthermore, the particle size of each elemental raw material is 200-400 mesh, and the purity is greater than 98%.

[0034] Furthermore, the specific raw materials of each element are as follows:

[0035] Cr powder, 200 mesh, 98% purity.

[0036] Ta powder, 300 mesh, 99.9% purity.

[0037] W powder, 250 mesh, 99% purity.

[0038] Nitrogen powder, 250 mesh, 99% purity.

[0039] V-powder, 250 mesh, 99% purity.

[0040] Zr particles, φ3mm, purity 99.95%.

[0041] Sb particles, φ3mm, purity 99.95%.

[0042] Co particles, φ3mm, purity 99.995%.

[0043] Hf particles, φ3mm, purity 99.995%.

[0044] Sn particles, φ3mm, purity 99.995%.

[0045] 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).

[0046] Another objective of this invention is to disclose the application of a ZrCoSb-based thermoelectric composite material containing a thermoelectric interface material in the field of thermoelectric devices.

[0047] Furthermore, the thermoelectric device is a single-leg thermoelectric device.

[0048] The thermoelectric interface material, the ZrCoSb-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:

[0049] 1) The high-entropy thermoelectric interface material (TEiM) Cr provided by this invention a V b Nb c Ta d W e With Zr h Co i Sb j HfkSn l After being composited with thermoelectric conversion materials (TEcM), the interfacial shear strength is far higher than the industry standard (>10MPa), for example, Cr 20 V 20 Nb 20 Ta 20 W 20 / Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The interfacial shear strength reaches 73.66 MPa, effectively solving the problem of insufficient interfacial bonding strength in traditional methods.

[0050] 2) The ZrCoSb-based thermoelectric composite material containing thermoelectric interface material of this invention has an extremely low contact resistivity of 0.792–1.5 µΩ•cm at the contact interface. 2 Furthermore, it remains stable, ensuring low energy loss during the electrical output process of the thermoelectric device and improving the overall conversion efficiency of the device.

[0051] 3) The ZrCoSb-based thermoelectric composite material containing thermoelectric interface material of the present invention exhibits excellent high-temperature stability, for example, Cr 20 V 20 Nb 20 Ta 20 W 20 / Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 After 7 days of service at 650℃, the interfacial shear strength only decreased from 73.67MPa to 50MPa, still far exceeding the industry standard (>20MPa), and the contact resistivity remained at an extremely low level. The minimal change in interfacial shear strength over service time indicates that the interfacial material possesses excellent thermal stability and can meet the long-term service requirements of thermoelectric devices in high-temperature environments.

[0052] 4) The thermal expansion coefficients of the thermoelectric interface material and the thermoelectric conversion material of the present invention are close, and the thermal stress on the interface during high-temperature service is small, which helps to avoid the generation of interface cracks and further ensures the bonding strength and service reliability of the interface.

[0053] 5) The TEiM of this invention is prepared by mechanical alloying, and the TEcM is prepared by hot pressing sintering. The two can form a reliable contact interface through one-step hot pressing sintering. The process is simple and suitable for large-scale production and application. Attached Figure Description

[0054] Figure 1 For Cr 20 V 20 Nb 20 Ta 20 W 20 SEM image of / TEcM thermoelectric interface material;

[0055] Figure 2 For Cr 20 V 20 Nb 20 Ta 20 Mo 20 SEM image of / TEcM thermoelectric interface material;

[0056] Figure 3 Cr annealed to 923K for 7 days 20 V 20 Nb 20 Ta 20 W 20 SEM image of / TEcM thermoelectric interface material;

[0057] Figure 4 Cr annealed to 923K for 7 days 20 Zr 20Nb 20 Ta 20 Mo 20 SEM image of / TEcM thermoelectric interface material;

[0058] Figure 5 For Cr 20 V 20 Nb 20 Ta 20 W 20 Thermal expansion coefficient diagram of TEcM;

[0059] Figure 6 For Cr 20 V 20 Nb 20 Ta 20 W 20 Shear strength diagram of / TEcM thermoelectric interface material;

[0060] Figure 7 For Cr 20 V 20 Nb 20 Ta 20 W 20 Shear strength diagram of / TEcM thermoelectric interface material after annealing at 650℃ for 7 days;

[0061] Figure 8 For Cr 20 V 20 Nb 20 Ta 20 W 20 / TEcM and Cr 20 Zr 20 Nb 20 Ta 20 Mo 20 / TEcM thermoelectric interface material contact resistance diagram;

[0062] Figure 9 For Cr 20 V 20 Nb 20 Ta 20 W 20 Contact resistance diagram after annealing at 650℃ for 7 days / TEcM. Detailed Implementation

[0063] 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:

[0064] 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.

[0065] 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.

[0066] In this specification, the numerical range indicated by "above" or "below" refers to the numerical range that includes the stated number.

[0067] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0068] In this specification, the terms "optional" or "optional" are used to indicate the use or omission of certain substances, components, procedures, application conditions, etc.

[0069] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be 15-25℃.

[0070] Unless otherwise specified, all reagents or instruments used in this instruction manual are commercially available products.

[0071] Example 1

[0072] This embodiment discloses a ZrCoSb-based thermoelectric composite material containing a thermoelectric interface material. 20 V 20 Nb 20 Ta 20 W 20 / Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 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: Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The chemical formula of TEiM is as follows: Cr 20 V 20 Nb 20 Ta 20 W 20 .

[0073] The preparation method of the ZrCoSb-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows:

[0074] Preparation of TEcM: Weigh each elemental raw material according to the designed ratio, and then ball mill (stainless steel ball, 10mm in diameter) for 12 hours under argon protection.

[0075] 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.

[0076] The preparation of the ZrCoSb-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows: First, a sample loading process is performed, specifically by spreading TEiM powder in a graphite mold, i.e., spreading it between the upper and lower TEiM blocks to form a sandwich-like structure. Then, hot-pressing sintering is performed. The TEiM powder and TEcM powder form the TEiM / TEcM contact interface through hot-pressing sintering at 1100℃, 60min, and 45MPa axial pressure. The heating rate during sintering is 100℃*min. -1 The thicknesses of the TEcM block and the TEiM layer are designed to be 4 mm and 0.3 mm, respectively.

[0077] Example 2

[0078] This embodiment discloses a ZrCoSb-based thermoelectric composite material containing a thermoelectric interface material. 15 V 25 Nb 20 Ta 20 W 20 / Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 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: Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The chemical formula of TEiM is as follows: Cr 15 V 25 Nb 20 Ta 20 W 20 .

[0079] The preparation method of the ZrCoSb-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows:

[0080] Preparation of TEcM: Weigh each elemental raw material according to the designed ratio, and then ball mill (stainless steel ball, 10mm in diameter) for 12 hours under argon protection.

[0081] 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.

[0082] The preparation of the ZrCoSb-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows: First, a sample loading process is performed, specifically by spreading TEiM powder in a graphite mold, i.e., spreading it between the upper and lower TEiM blocks to form a sandwich-like structure. Then, hot-pressing sintering is performed. The TEiM powder and TEcM powder form the TEiM / TEcM contact interface through hot-pressing sintering at 1100℃, 60min, and 45MPa axial pressure. The heating rate during sintering is 100℃*min. -1 The thicknesses of the TEcM block and the TEiM layer are designed to be 4 mm and 0.3 mm, respectively.

[0083] Table 1 Cr in Example 2 15 V 25 Nb 20 Ta 20 W 20 / TecM's performance indicators

[0084]

[0085] Example 3

[0086] This embodiment discloses a ZrCoSb-based thermoelectric composite material containing a thermoelectric interface material. 25 V 15 Nb 20 Ta 20 W 20 / Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 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: Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The chemical formula of TEiM is as follows: Cr 25 V 15 Nb 20 Ta 20 W 20 .

[0087] The preparation method of the ZrCoSb-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows:

[0088] Preparation of TEcM: Weigh each elemental raw material according to the designed ratio, and then ball mill (stainless steel ball, 10mm in diameter) for 12 hours under argon protection.

[0089] 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.

[0090] The preparation of the ZrCoSb-based thermoelectric composite material containing the high-entropy thermoelectric interface material is as follows: First, a sample loading process is performed, specifically by spreading TEiM powder in a graphite mold, i.e., spreading it between the upper and lower TEiM blocks to form a sandwich-like structure. Then, hot-pressing sintering is performed. The TEiM powder and TEcM powder form the TEiM / TEcM contact interface through hot-pressing sintering at 1100℃, 60min, and 45MPa axial pressure. The heating rate during sintering is 100℃*min. -1 The thicknesses of the TEcM block and the TEiM layer are designed to be 4 mm and 0.3 mm, respectively.

[0091] Table 2 Cr in Example 3 25 V 15 Nb 20 Ta 20 W 20 / TEcM's performance indicators

[0092]

[0093] Comparative Example 1

[0094] This comparative example discloses a composite material Cr 20 Zr 20 Nb 20 Ta 20 Mo 20 / Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The chemical formula of TEcM is as follows: Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The chemical formula of TEiM is as follows: Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 Its preparation method is the same as that in Example 1.

[0095] The composite materials of the examples and comparative examples were tested respectively. The test methods and test results are as follows:

[0096] 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, the interface bonding in Comparative Example 1 is also excellent, with no diffusion. Figure 3 As shown, after annealing at 473K for 7 days, the interface bonding in Example 1 remained good, with no diffusion. Figure 4 As shown, after annealing at 473K for 7 days, the interface bonding in Comparative Example 1 remained good, with no diffusion. Figure 5 As shown, the high-entropy thermoelectric interface material (TEiM) and the thermoelectric conversion material (TEcM) in Example 1 exhibit good thermal expansion matching. For example... Figure 6 As shown, Example 1 and Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The bonding strength is 73.66 MPa, while the industry standard is >10 MPa, indicating that it is significantly higher than the industry standard. For example... Figure 7 As shown, after annealing at 923K for 7 days, Example 1 and Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The bonding strength is 50 MPa, while the industry standard is >10 MPa, indicating that it far exceeds the industry standard and possesses high thermal stability. For example... Figure 8 As shown, Example 1 and Comparative Example 1 are compared with Zr 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The contact resistivity at the interface is extremely low, at 0.792 µΩ•cm. 2 (<10 µΩ•cm) 2 ).like Figure 9 As shown, after annealing at 923K for 7 days, Examples 1 and Comparative Example 1 were compared with Zr. 0.8 CoSb 0.8 Hf 0.2 Sn 0.2 The contact resistivity at the interface is extremely low, at 3.172 µΩ•cm. 2 (<10 µΩ•cm) 2 It exhibits high thermal stability. As shown in Table 1, the Cr in Example 2... 15 V 25 Nb 20 Ta 20 W 20 All performance indicators of / TEcM exceed industry standards. As shown in Table 2, the Cr in Example 3 25 V 15 Nb20 Ta 20 W 20 / TEcM's performance indicators all exceed industry standards.

[0097] The tests for coefficient of thermal expansion, shear strength, and contact resistivity 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).

[0098] The coefficient of thermal expansion is an important parameter for measuring the degree of strain of a material at different temperatures, and this parameter is of great significance for selecting thermoelectric interface materials. For example... Figure 6 As shown, Cr 20 V 20 Nb 20 Ta 20 W 20 The thermal expansion property of Cr is close to that of TEcM, which indicates that in the high-temperature range, Cr 20 V 20 Nb 20 Ta 20 W 20 The / TEcM interface experiences less thermal stress, which helps to avoid the occurrence of interfacial cracks and improves the bonding strength and high-temperature stability of the interface.

[0099] 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 650°C at a rate of 7°C / min, and held for different times to simulate the actual service environment of the device. Figure 7 As shown in Figures 8, 9, and 10, 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 650℃, Cr 20 V 20 Nb 20 Ta 20 W 20 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, Cr 20 V 20 Nb 20 Ta 20 W 20 The shear strength of the / TEcM interface only decreased from 73.67 MPa to 50 MPa, both of which are far greater than the qualified interface shear strength of 10 MPa. Cr 20 V 20 Nb 20Ta 20 W 20 / TEcM has an extremely low interfacial resistivity of 0.792µΩ•cm 2 And it remains stable. After 7 days of service at 650℃, the contact interface still meets the requirements of bonding strength >10MPa and contact resistivity of 3.172µΩ•cm. 2 <10μΩ*cm 2 This meets industry requirements and offers competitive interface stability performance within the current industry.

[0100] 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 650°C, the shear strength of the contact interface is >20 MPa, and the contact resistivity remains extremely low.

[0101] 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 thermoelectric interface material, characterized in that, The general chemical formula is Cr a V b Nb c Ta d W e Where a = 10–30; b = 10–40; c = 10–40; d = 10–40; e = 10–40, and a, b, c, d, and e represent the atomic percentages of each element.

2. A method for preparing the 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, ball milling under inert gas protection to obtain alloy powder, which is the thermoelectric interface material.

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

4. A ZrCoSb-based thermoelectric composite material containing a thermoelectric interface material, characterized in that, The 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 ZrCoSb-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, and the thermoelectric conversion material is a p-type Zr. h Co i Sb j HfkSn l h = 0.1~1; i = 0.8~1.3; j = 0.1~1; k = 0.1~0.5; l = 0.1~0.5, where h, i, j, k, and l represent the atomic percentage of each element.

6. The ZrCoSb-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 ZrCoSb-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 ZrCoSb-based thermoelectric composite material containing the thermoelectric interface material.

8. The method for preparing the ZrCoSb-based thermoelectric composite material containing the thermoelectric interface material according to claim 7, characterized in that, The sintering process is hot pressing sintering, and the temperature of the hot pressing sintering is 900-1200℃; And / or, the hot pressing sintering time is 50 to 80 minutes; And / or, the axial pressure of the hot pressing sintering is 40 to 100 MPa; And / or, the heating rate to the hot-pressing sintering temperature is 10 to 100 °C / min.

9. The application of a ZrCoSb-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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