A laminated high-temperature flexible thermoelectric energy harvesting device and method of manufacture

Abstract

A laminated high-temperature flexible thermoelectric energy collection device and a preparation method, a connecting metal silver thin film and an indium oxide sensitive thin film are printed on a flexible mica sheet substrate; the indium oxide sensitive thin film and the connecting metal silver thin film are multiple and arranged in series in the same plane, and electrical communication is realized in sequence according to the connection order of "thermoelectric arm-Z type connecting electrode"; the high-temperature-resistant thermoelectric material is used, the thermal substrate is cut along the thermoelectric device array mold through the cutting technology, and the structure design of the cold end separation is formed, the preparation method is simple, the power density is considerable, the recycling of high-temperature waste heat can be realized, the environment is friendly, the power density is high, and the installation is easy, and the high-temperature recycling in industrial production has a broad application prospect.

Description

Technical Field

[0001] This invention belongs to the field of flexible thermoelectric energy harvesting device design and fabrication technology and high-temperature waste heat recovery technology, and specifically relates to a layered high-temperature flexible thermoelectric energy harvesting device and its fabrication method. Background Technology

[0002] With the rise and development of industrial society, traditional energy sources are being used extensively, leading to increasingly depleted reserves. Thermoelectric conversion devices, which directly convert heat energy into electrical energy using thermoelectric materials, offer advantages such as long lifespan and environmental friendliness. They not only improve energy efficiency but also hold the promise of replacing traditional batteries to provide wireless power for electronic devices. However, traditional thermoelectric conversion devices based on bismuth telluride only exhibit excellent thermoelectric performance in low-temperature regions; their rigid structure limits their application environments. Furthermore, thermoelectric materials used in medium- and high-temperature regions, such as lead telluride and its related alloys, are highly toxic and harmful chemicals, posing a threat to the environment. Therefore, based on existing thermoelectric materials with excellent high-temperature performance, this study aims to design a flexible thermoelectric collection device applicable to high-temperature regions through structural optimization. This device can recover and utilize medium- and high-temperature waste heat, improving energy efficiency.

[0003] The existing patent application with patent number CN202210812597.4 discloses a flexible thermoelectric device with a wave-shaped thermoelectric arm and its manufacturing method. It utilizes the wave-shaped undulating structure to establish an effective temperature difference in the thermoelectric arm, which can be applied to the heat collection and utilization of heat source surfaces with large curvature. However, this patent application is limited by the material system and structure and cannot realize the collection of waste heat at medium and high temperatures. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a stacked high-temperature flexible thermoelectric energy harvesting device and its preparation method, which can realize the recovery and utilization of high-temperature waste heat, is environmentally friendly, has high power density, is easy to install, and has broad application prospects for high-temperature reuse in industrial production.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A layered high-temperature flexible thermoelectric energy harvesting device has a flexible mica substrate 1 on which a connecting silver film 2 and an indium oxide sensitive film 3 are printed. There are multiple indium oxide sensitive films 3 and connecting silver films 2, which are arranged at intervals in the same plane. One side of the flexible mica substrate 1 on which the indium oxide sensitive film 3 and connecting silver film 2 are printed is cut, and the indium oxide sensitive film 3 and connecting silver film 2 on the cut side are not connected and are in a free and movable state. An indium oxide sensitive film 3-connecting silver film 2, i.e., a "thermoelectric arm-Z-type connecting electrode", is formed on the flexible mica substrate 1 to realize electrical connection.

[0007] The first connecting silver film 2 and the last indium oxide sensitive film 3 are both bonded with metal leads 5 using high-temperature conductive silver paste; the surfaces of the indium oxide sensitive film 3 and the connecting silver film 2 are both provided with an aluminum oxide protective layer 4, which completely covers them.

[0008] A method for fabricating a stacked high-temperature flexible thermoelectric energy harvesting device includes the following steps:

[0009] S1: Cut the flexible mica substrate 1; and then grind, clean, and dry it;

[0010] S2: An indium oxide sensitive film 3 is prepared on a flexible mica substrate 1 by screen printing, and then dried; a connecting silver film 2 is prepared on the flexible mica substrate 1, wherein multiple connecting silver films 2 and indium oxide sensitive films 3 are arranged in series in the same plane, and then dried; one side of the flexible mica substrate 1 with the indium oxide sensitive film 3 and connecting silver film 2 printed on it is cut, and the indium oxide sensitive film 3 and connecting silver film 2 on the cut side are not connected and are in a free and movable state, forming a temperature difference between the hot and cold ends;

[0011] S3: The obtained product is annealed in a high-temperature aerobic environment;

[0012] S4: An aluminum oxide protective layer 4 with a thickness of 25-40 μm is prepared on the surface of the indium oxide sensitive film 3 and the connecting silver film 2, and then dried at a temperature of 120℃-150℃.

[0013] S5: High-temperature conductive silver paste is used to bond the metal lead 5, the first connecting metal silver film 2, and the last indium oxide sensitive film 3, and then a layer of high-temperature cement adhesive is applied to the conductive silver paste.

[0014] S6: Remove excess substrate from the product obtained in step S5 by pressing with a mold; assemble the hot ends of the thermoelectric device array in a stacked manner to obtain the final product.

[0015] Step S2 specifically involves:

[0016] 2-1. The screen printing paste for the indium oxide sensitive film 3 includes: 1.0g to 2.0g of 30-100nm indium oxide powder, 0.15g to 0.25g of epoxy resin, 0.12g to 0.25g of polyetheramine, and 0.10g to 0.25g of terpineol. The indium oxide sensitive film layer 3 is prepared using a screen with a mesh size between 200 and 250 mesh. The screen is fixed on the screen printing table, and the dried flexible mica substrate 1 is placed under the screen so that the paste is evenly distributed on the flexible mica substrate 1 through the screen, with a thickness of 20-30 micrometers.

[0017] 2-2: Place the product with the printed indium oxide sensitive thin film array on a heating table to dry. The drying temperature is 120℃-150℃ and the time is 15-20 minutes.

[0018] 2-3: The screen printing paste for connecting the metallic silver film 2 includes: 1.5g to 2.2g of 50-200nm silver powder, 0.15g to 0.25g of epoxy resin, 0.12g to 0.25g of polyetheramine, and 0.15g to 0.30g of terpineol. The screen is fixed on the screen printing table, and the product of the indium oxide sensitive film array dried in step 2-2 is placed under the screen, so that the paste is evenly covered on the flexible mica substrate 1 printed with the indium oxide sensitive film array through the screen; the thickness is 10-12 micrometers, and the metallic silver film 2 is printed.

[0019] 2-4: Place the product with the printed and connected metallic silver film 2 on a heating table to dry at a temperature of 150℃-180℃ for 20-25 minutes.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The combination of the flexible mica substrate, the indium oxide sensitive layer, and the connecting metal film Ag (silver) selected in the device of the present invention makes the entire thermoelectric collection device flexible. The connecting metal is Ag, which has the advantages of high melting point and high conductivity. The protective layer material is alumina, which has good high-temperature chemical stability and insulation performance. It has good high-temperature applicability, can realize the collection of high-temperature thermoelectric energy, and can be applied to complex heat source surfaces.

[0022] 2. The stacked flexible thermoelectric energy harvester designed in this invention is prepared using screen printing technology, which has the advantages of simple preparation process and high preparation efficiency.

[0023] 3. The alumina protective layer added in this invention can prevent thermoelectric devices from oxidizing and failing under high temperature conditions, improve the stability of the output signal, and extend the working life of the prepared devices under high temperature conditions.

[0024] 4. The stacked flexible thermoelectric energy harvester designed in this invention has a large space utilization rate, high power density, and can be attached without damage.

[0025] 5. The stacked thermoelectric array structure proposed in this invention can be installed on various complex curved surfaces and can be applied in a wide temperature range, with the highest application temperature reaching 1000℃. It can also recover and utilize high-temperature waste heat in an environmentally friendly manner. Attached Figure Description

[0026] Figure 1 This is a structural diagram of the present invention.

[0027] Figure 2 This is a partial enlarged cross-sectional view of the present invention.

[0028] Figure 3 This is an assembly diagram of the present invention.

[0029] Figure 4 This is the test output power diagram of the present invention.

[0030] In the figure, 1. Flexible mica substrate, 2. Connecting silver film, 3. Indium oxide sensitive film, 4. Aluminum oxide protective layer, 5. Metal lead. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] refer to Figures 1 to 3 A layered high-temperature flexible thermoelectric energy harvesting device has a flexible mica substrate 1 on which a connecting silver film 2 and an indium oxide sensitive film 3 are printed. The flexible mica substrate 1 makes the entire thermoelectric energy harvesting device flexible and can be attached to various complex curved surface structures without damage.

[0034] The indium oxide sensitive film 3 and the connecting silver film 2 are multiple and arranged at intervals in the same plane; one side of the flexible mica substrate 1 on which the indium oxide sensitive film 3 and the connecting silver film 2 are printed is cut, and the indium oxide sensitive film 3 and the connecting silver film 2 on the cut edge are not connected and are in a free and movable state, forming an indium oxide sensitive film 3-connecting silver film 2 series connection form, i.e., "thermoelectric arm-Z-type connecting electrode", on the flexible mica substrate 1 to achieve electrical connection; such an array-stacked structure has a large space utilization rate and can effectively increase the power density of thermoelectric devices.

[0035] Both the first connecting silver film 2 and the last indium oxide sensitive film 3 are bonded to the metal leads 5 using high-temperature conductive silver paste; the surfaces of the indium oxide sensitive film 3 and the connecting silver film 2 are provided with an aluminum oxide protective layer 4, which completely covers them.

[0036] Figure 2 This is a cross-sectional view of a single array unit. The specific order of thin film preparation can be seen from the figure. After pretreatment of the substrate 1, an indium oxide sensitive film 3 with a thickness of 20-30 micrometers is printed first, followed by a connecting silver film 2 with a thickness of 10-12 micrometers, and then an aluminum oxide protective layer with a thickness of 20 micrometers is printed to prevent the sensitive material from oxidizing in a high-temperature environment.

[0037] The flexible mica substrate 1 is cut along the edge printed with an indium oxide sensitive film 3 and a connecting silver film 2. The indium oxide sensitive film 3 and the connecting silver film 2 at the cut ends are not connected and are in a free and movable state, forming a temperature difference between the hot and cold ends. Figure 1 The dimensions of a single unit are 30mm in length and 15mm in width; the dimensions of a thermal node are 5mm in length and 4mm in width. Figure 1 The demonstration shows an array of thermoelectric devices after being cut using a mold. This reduces the mass of the thermoelectric devices and allows for easy bending of the cold ends. After testing, the mass of a single acquisition array was approximately 10¹ mg.

[0038] Figure 3 This is a schematic diagram of a thermoelectric array stacked on a curved heat source. It can be seen that the present invention has the ability to be installed on the surface of complex heat sources. At the same time, this stacked structure (shaped like a pine cone or petal) can effectively separate the cold end and hot end of the thermoelectric device, realizing the recovery and utilization of medium and high temperature waste heat.

[0039] The present invention discloses a method for fabricating a stacked high-temperature flexible thermoelectric energy harvesting device, comprising the following steps:

[0040] S1: Cut the flexible mica sheet substrate 1 to a suitable size, and use 220-grit sandpaper to polish the flexible mica sheet 1 to increase the surface roughness of the substrate so that the substrate and the film layer are more firmly bonded. Next, clean the surface of the substrate with deionized water, and then dry it on the heating table to remove water stains for later use.

[0041] S2: An indium oxide sensitive film 3 is prepared on a flexible mica substrate 1 by screen printing, and then dried; a connecting silver film 2 is prepared on the flexible mica substrate 1, wherein multiple connecting silver films 2 and indium oxide sensitive films 3 are arranged in series in the same plane, and then dried; one side of the flexible mica substrate 1 with the indium oxide sensitive film 3 and connecting silver film 2 printed on it is cut, and the indium oxide sensitive film 3 and connecting silver film 2 on the cut side are not connected and are in a free and movable state, forming a temperature difference between the hot and cold ends;

[0042] 2-1. The screen printing paste for the indium oxide sensitive film 3 includes: 1.5g of 50nm indium oxide powder, 0.20g of epoxy resin, 0.20g of polyetheramine, and 0.20g of terpineol. The indium oxide sensitive film layer 3 is prepared using a 200-mesh screen. The size of a single indium oxide sensitive film layer 3 is 30mm × 5mm, and the spacing between two adjacent sensitive layers is 15mm. The screen is fixed on the screen printing table, and the dried flexible mica sheet substrate 1 is placed under the screen. A squeegee is used to spread the paste evenly through the screen onto the flexible mica sheet substrate 1, with a thickness of 22 micrometers.

[0043] 2-2: Place the product with the printed indium oxide sensitive thin film array on a heating table to dry at 150℃ for 18 minutes;

[0044] 2-3: To ensure the normal operation of thermoelectric devices in high-temperature regions, high-melting-point, high-conductivity metallic silver is selected to prepare a connecting silver film 2. The screen printing paste for the connecting silver film 2 includes: 2.0g of 80nm silver powder, 0.22g of epoxy resin, 0.12g of polyetheramine, and 0.15g of terpineol. The screen is fixed on the screen printing table, and the product with the printed indium oxide sensitive film array is placed under the screen. A squeegee is used to make the screen printing paste for the connecting silver film 2 evenly cover the flexible mica substrate 1 with the printed indium oxide sensitive film array through the screen, with a thickness of 11 micrometers. The printed connecting silver film 2 has a Z-shaped shape and a width of 5mm.

[0045] 2-4: Place the product with the printed silver film 2 on the heating table to dry at 180℃ for 25 minutes. Although silver is easily oxidized at room temperature, the change range of conductivity of the silver film after low-temperature drying and high-temperature annealing does not affect its role as a connecting electrode.

[0046] S3: Anneal the processed product with thin film array in air at 350℃ for 1.5 hours to make the microstructure of the indium oxide sensitive film more compact and the thermoelectric properties more stable.

[0047] S4: A layer of aluminum oxide protective layer 4 with a thickness of 20 micrometers is printed on the annealed thermoelectric sensitive film array using screen printing process and the drying temperature is 150℃. The purpose is to prevent the volatilization of the adhesive in the sensitive film under high temperature environment and ensure better high temperature stability.

[0048] S5: Finally, high-temperature conductive silver paste is used to bond the metal lead 5, the first and second connecting metal silver film 2, and the last indium oxide sensitive film 3, and then a layer of high-temperature cement adhesive is applied to the conductive silver paste.

[0049] S6: Remove excess substrate from the product obtained in step S5 by pressing with a mold; assemble the hot ends of the obtained thermoelectric device array in a stacked manner to obtain a multilayer high-density thermoelectric device, which can be attached to various complex curved structures using high-temperature inorganic adhesive.

[0050] To increase the temperature difference between the hot and cold ends, the low thermal conductivity of air is utilized to expose more of the cold end to the air, thereby increasing the heat transfer between the cold end and the outside air; therefore, the excess mica substrate is removed along the edge of the sensitive layer through a mold cutting process.

[0051] To improve the power density of the thermoelectric array, a curved mold is used to shape the thermoelectric legs into an arc shape resembling unfolded petals, while simultaneously increasing the distance between the hot and cold ends. Based on this, a pinecone-like layered structure is proposed for mounting, using high-temperature inorganic adhesive to bond the heat source surface and the thermoelectric device substrate, specifically as follows... Figure 3 As shown, this thermoelectric device can achieve the recovery and utilization of medium- and high-temperature waste heat by having the hot end in close contact with a complex heat source and the cold end moving away from the cold end with different curvatures. The invented stacked medium- and high-temperature flexible thermoelectric energy harvesting device has been successfully fabricated.

[0052] The power output test of the thermoelectric device in this embodiment

[0053] An indium oxide thin film with a width of 5 mm and a length of 30 mm was prepared on a mica substrate using screen printing. The film was then dried in an air atmosphere at 150 °C on a heating stage. Silver was then printed as the electrode material and dried in an air atmosphere at 180 °C. Finally, an aluminum oxide protective layer was printed on the sensitive layer and the electrode layer and dried at 150 °C. The sample preparation was then complete.

[0054] The power of the prepared indium oxide-silver thermoelectric device was tested. Figure 4 The maximum output power curves of a single indium oxide-silver thermoelectric device array are shown under different temperature differences. Therefore, it can be seen that the thermoelectric device proposed in this invention can effectively realize the recovery and utilization of medium- and high-temperature waste heat.

[0055] Example 2

[0056] The structure of this embodiment is the same as that of Embodiment 1. The preparation method of this embodiment is as follows:

[0057] S1: Cut the flexible mica sheet substrate 1 to a suitable size, and use 220-grit sandpaper to polish the flexible mica sheet 1 to increase the surface roughness of the substrate so that the substrate and the film layer are more firmly bonded. Next, clean the surface of the substrate with deionized water, and then dry it on the heating table to remove water stains for later use.

[0058] S2: An indium oxide sensitive film 3 is prepared on a flexible mica substrate 1 by screen printing, and then dried; a connecting silver film 2 is prepared on the flexible mica substrate 1, wherein multiple connecting silver films 2 and indium oxide sensitive films 3 are arranged in series in the same plane, and then dried; one side of the flexible mica substrate 1 with the indium oxide sensitive film 3 and connecting silver film 2 printed on it is cut, and the indium oxide sensitive film 3 and connecting silver film 2 on the cut side are not connected and are in a free and movable state, forming a temperature difference between the hot and cold ends;

[0059] 2-1. The screen printing paste for the indium oxide sensitive film 3 includes: 1.5g of 50nm indium oxide powder, 0.17g of epoxy resin, 0.17g of polyetheramine, and 0.1g of terpineol. The indium oxide sensitive film layer 3 is prepared using a 200-mesh screen. The size of a single indium oxide sensitive film layer 3 is 30mm × 5mm, and the spacing between two adjacent sensitive layers is 15mm. The screen is fixed on the screen printing table, and a dried flexible mica sheet substrate 1 is placed under the screen. A squeegee is used to spread the paste evenly through the screen onto the flexible mica sheet substrate 1, with a thickness of 35 micrometers.

[0060] 2-2: Place the product with the printed indium oxide sensitive thin film array on a heating table to dry at 150℃ for 25 minutes;

[0061] 2-3: To ensure the normal operation of thermoelectric devices in high-temperature regions, high-melting-point, high-conductivity metallic silver is selected to prepare a connecting silver film 2. The screen printing paste for the connecting silver film 2 includes: 2.0g of 80nm silver powder, 0.22g of epoxy resin, 0.12g of polyetheramine, and 0.15g of terpineol. The screen is fixed on the screen printing table, and the product with the printed indium oxide sensitive film array is placed under the screen. A squeegee is used to make the screen printing paste for the connecting silver film 2 evenly cover the flexible mica substrate 1 with the indium oxide sensitive film array through the screen, with a thickness of 11 micrometers. The printed connecting silver film 2 has a Z-shaped shape and a width of 5mm.

[0062] 2-4: Place the product with the printed silver film 2 on a heating table to dry at 180℃ for 25 minutes. Although silver is easily oxidized at room temperature, the conductivity variation range of the silver film after low-temperature drying and high-temperature annealing does not affect its role as a connecting electrode.

[0063] S3: Anneal the processed product with thin film array in air at 350℃ for 1.5 hours to make the microstructure of the indium oxide sensitive film more compact and the thermoelectric properties more stable.

[0064] S4: A layer of aluminum oxide protective layer 4 with a thickness of 20 micrometers is printed on the annealed thermoelectric sensitive film array using screen printing process and the drying temperature is 150℃. The purpose is to prevent the volatilization of the adhesive in the sensitive film under high temperature environment and ensure better high temperature stability.

[0065] S5: Finally, high-temperature conductive silver paste is used to bond the metal lead 5, the first and second connecting metal silver film 2, and the last indium oxide sensitive film 3, and then a layer of high-temperature cement adhesive is applied to the conductive silver paste.

[0066] S6: Remove excess substrate from the product obtained in step S5 by pressing with a mold; assemble the hot ends of the obtained thermoelectric device array in a stacked manner to obtain a multilayer high-density thermoelectric device, which can be attached to various complex curved structures using high-temperature inorganic adhesive.

[0067] Because the hot ends of the thermoelectric device array in this embodiment are assembled in a stacked manner, the space utilization rate is large, and it can be attached to various complex curved surface structures without damage, effectively increasing the power density of the thermoelectric device.

[0068] Example 3

[0069] The structure of this embodiment is the same as that of Embodiment 1. The preparation method of this embodiment is as follows:

[0070] S1: Cut the flexible mica sheet substrate 1 to a suitable size, and use 220-grit sandpaper to polish the flexible mica sheet 1 to increase the surface roughness of the substrate so that the substrate and the film layer are more firmly bonded. Next, clean the surface of the substrate with deionized water, and then dry it on the heating table to remove water stains for later use.

[0071] S2: An indium oxide sensitive film 3 is prepared on a flexible mica substrate 1 by screen printing, and then dried; a connecting silver film 2 is prepared on the flexible mica substrate 1, wherein multiple connecting silver films 2 and indium oxide sensitive films 3 are arranged in series in the same plane, and then dried; one side of the flexible mica substrate 1 on which the indium oxide sensitive film 3 and the connecting silver film 2 are printed is cut, and the indium oxide sensitive film 3 and the connecting silver film 2 on the cut side are not connected and are in a free and movable state, forming a temperature difference between the hot and cold ends;

[0072] 2-1. The screen printing paste for the indium oxide sensitive film 3 includes: 2.0g of 80nm indium oxide powder, 0.20g of epoxy resin, 0.25g of polyetheramine, and 0.25g of terpineol. The indium oxide sensitive film layer 3 is prepared using a 200-mesh screen. The size of a single indium oxide sensitive film layer 3 is 30mm × 5mm, and the spacing between two adjacent sensitive layers is 15mm. The screen is fixed on the screen printing table, and a dried flexible mica sheet substrate 1 is placed under the screen. A squeegee is used to spread the paste evenly through the screen onto the flexible mica sheet substrate 1, with a thickness of 33 micrometers.

[0073] 2-2: Place the product with the printed indium oxide sensitive thin film array on a heating table to dry at 150℃ for 20 minutes;

[0074] 2-3: To ensure the normal operation of thermoelectric devices in high-temperature regions, high-melting-point, high-conductivity metallic silver is selected to prepare a connecting silver film 2. The screen printing paste for the connecting silver film 2 includes: 2.0g of 80nm silver powder, 0.22g of epoxy resin, 0.12g of polyetheramine, and 0.15g of terpineol. The screen is fixed on the screen printing table, and the product with the printed indium oxide sensitive film array is placed under the screen. A squeegee is used to make the screen printing paste for the connecting silver film 2 evenly cover the flexible mica substrate 1 with the indium oxide sensitive film array through the screen, with a thickness of 11 micrometers. The printed connecting silver film 2 has a Z-shaped shape and a width of 5mm.

[0075] 2-4: Place the product with the printed silver film 2 on a heating table to dry at 180℃ for 25 minutes. Although silver is easily oxidized at room temperature, the conductivity variation range of the silver film after low-temperature drying and high-temperature annealing does not affect its role as a connecting electrode.

[0076] S3: Anneal the processed product with thin film array in air at 350℃ for 1.5 hours to make the microstructure of the indium oxide sensitive film more compact and the thermoelectric properties more stable.

[0077] S4: A layer of aluminum oxide protective layer 4 with a thickness of 20 micrometers is printed on the annealed thermoelectric sensitive film array using screen printing technology. The drying temperature is 120℃-150℃. The purpose is to prevent the volatilization of the adhesive in the sensitive film under high temperature environment and ensure better high temperature stability.

[0078] S5: Finally, high-temperature conductive silver paste is used to bond the metal lead 5, the first and second connecting metal silver film 2, and the last indium oxide sensitive film 3, and then a layer of high-temperature cement adhesive is applied to the conductive silver paste.

[0079] S6: Remove excess substrate from the product obtained in step S5 by pressing and cutting with a mold; assemble the hot ends of the obtained thermoelectric device array into a multilayer high-density thermoelectric device by stacking the hot ends layer by layer, and attach it to various complex curved surface structures using high-temperature inorganic adhesive.

[0080] The stacked thermoelectric array structure proposed in this embodiment can be installed on various complex curved surfaces. It can be applied to high-temperature heat source environments on curved surfaces while maintaining the temperature difference between the hot and cold ends. It can successfully collect thermoelectric energy in medium and high temperature regions and can be applied in a wide temperature range, with the highest application temperature reaching 1000℃. It can also recover and utilize high-temperature waste heat in an environmentally friendly manner.

Claims

1. A layered high-temperature flexible thermoelectric energy harvesting device, characterized in that, A connecting silver film (2) and an indium oxide sensitive film (3) are printed on a flexible mica substrate (1). There are multiple indium oxide sensitive films (3) and connecting silver films (2) arranged at intervals in the same plane. One side of the flexible mica substrate (1) on which the indium oxide sensitive film (3) and connecting silver films (2) are printed is cut. The indium oxide sensitive film (3) and connecting silver films (2) on the cut side are not connected and are in a free and movable state. An indium oxide sensitive film (3) and connecting silver film (2) are formed on the flexible mica substrate (1) in a series form, namely "thermoelectric arm - Z-type connecting electrode", to realize electrical connection.

2. The layered high-temperature flexible thermoelectric energy harvesting device according to claim 1, characterized in that, The first connecting silver film (2) and the last indium oxide sensitive film (3) are both bonded with metal leads (5) using high-temperature conductive silver paste; the surfaces of the indium oxide sensitive film (3) and the connecting silver film (2) are both provided with aluminum oxide protective layer (4) and are completely covered.

3. The method for preparing a stacked high-temperature flexible thermoelectric energy harvesting device according to claim 1, characterized in that, Includes the following steps: S1: Cut the flexible mica substrate (1); and polish, clean and dry it; S2: An indium oxide sensitive film (3) is prepared on a flexible mica substrate (1) by screen printing and then dried; a connecting silver film (2) is prepared on the flexible mica substrate (1), wherein the connecting silver film (2) and the indium oxide sensitive film (3) are multiple and arranged in series in the same plane, and then dried; the flexible mica substrate (1) with the printed indium oxide sensitive film (3) and the connecting silver film (2) is cut on one side, and the indium oxide sensitive film (3) and the connecting silver film (2) on the cut side are not connected and are in a free and movable state, forming a temperature difference between the hot and cold ends; S3: The obtained product is annealed in a high-temperature aerobic environment; S4: An aluminum oxide protective layer (4) with a thickness of 25-40 μm is prepared on the surface of the indium oxide sensitive film (3) and the connecting silver film (2), and then dried at a temperature of 120℃-150℃. S5: Finally, high-temperature conductive silver paste is used to bond the metal lead (5) to the first and second connecting metal silver film (2) and the last indium oxide sensitive film (3), and then a layer of high-temperature cement paste is applied to the conductive silver paste. S6: Remove excess substrate from the product obtained in step S5 by pressing with a mold; assemble the hot ends of the thermoelectric device array in a stacked manner to obtain the final product.

4. The method for preparing a stacked high-temperature flexible thermoelectric energy harvesting device according to claim 3, characterized in that, Step S2 specifically involves: 2-1. The screen printing paste for the indium oxide sensitive film (3) includes: 1.0g to 2.0g of 30-100nm indium oxide powder, 0.15g to 0.25g of epoxy resin, 0.12g to 0.25g of polyetheramine, and 0.10g to 0.25g of terpineol. The indium oxide sensitive film layer (3) is prepared using a screen with a mesh size between 200 and 250 mesh. The screen is fixed on the screen printing table, and the dried flexible mica substrate (1) is placed under the screen so that the paste is evenly covered on the flexible mica substrate (1) through the screen with a thickness of 20-30 micrometers. 2-2: Place the product with the printed indium oxide sensitive thin film array on a heating table to dry. The drying temperature is 120℃-150℃ and the time is 15-20 minutes. 2-3: The screen printing paste for connecting the silver film (2) includes: 1.5g to 2.2g of 50-200nm silver powder, 0.15g to 0.25g of epoxy resin, 0.12g to 0.25g of polyetheramine, and 0.15g to 0.30g of terpineol; the screen is fixed on the screen printing table, and the product of the indium oxide sensitive film array dried in step 2-2 is placed under the screen, so that the paste is evenly covered on the flexible mica substrate (1) printed with the indium oxide sensitive film array through the screen; the thickness is 10-12 micrometers, and the silver film (2) is connected. 2-4: Place the product with the printed metal silver film (2) on the heating table to dry. The drying temperature is 150℃-180℃ and the time is 20-25 minutes.

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