Preparation method of In-plane structure flexible thermoelectric device and flexible thermoelectric device

Abstract

The invention provides a preparation method of a flexible thermoelectric device and the flexible thermoelectric device, a P-type thermoelectric film and an N-type thermoelectric film are alternately bonded on a flexible substrate side by side according to pre-designed structural parameters, a connecting electrode is prepared between the P-type thermoelectric film and the N-type thermoelectric film, and then two copper wires are led out; and then pasting a flexible heat insulation layer on the upper surface to obtain a flexible device, then folding the flexible device along a center line perpendicular to the length direction of the thermoelectric film, carrying out compression molding, and finally carrying out surface packaging to obtain the flexible thermoelectric device. According to the method, a flexible heat insulation layer is added on the upper surface of an In-plane structure flexible thermoelectric film and is folded, so that the In-plane structure flexible thermoelectric device with a hot surface and a cold surface in the vertical direction is formed, the heat distribution of the In-plane structure flexible thermoelectric device is optimized, and the In-plane structure flexible thermoelectric device can be used for thermoelectric refrigeration or thermoelectric power generation of a geometric surface with complex curvature change.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible thermoelectric device manufacturing, and in particular to a method for preparing an In-plane structure flexible thermoelectric device and a flexible thermoelectric device. Background Art

[0002] Thermoelectric devices can directly realize the mutual conversion between thermal energy and electrical energy, and are a new functional device for obtaining green energy. Thermoelectric devices mainly have two application directions: thermoelectric refrigeration and temperature difference power generation, which respectively utilize the Peltier effect and the Seebeck effect. At present, the substrate materials of thermoelectric devices are mostly ceramic materials. The prepared thermoelectric devices have the shortcomings of large brittleness and inflexibility, which makes them only applicable to the field of mechanical and electronic equipment with planes. In real life, the human body and many mechanical and electronic equipment have geometric surfaces with complex curvature changes. Thermoelectric devices with ceramic substrates cannot fit perfectly with their surfaces, which greatly reduces the energy conversion efficiency. This makes the development of flexible substrate thermoelectric devices a focus in the thermoelectric field.

[0003] Flexible thermoelectric devices can be divided into two categories according to the direction of the temperature gradient: Cross-plane structure and In-plane structure. The direction of the temperature gradient of the flexible thermoelectric device with Cross-plane structure is perpendicular to the substrate plane, and its preparation process is complex and costly. The direction of the temperature gradient of the flexible thermoelectric device with In-plane structure is parallel to the substrate plane, and the preparation process is simple. It can be completed by traditional thin film preparation process, and it is easy to achieve large-scale production. However, whether it is used for thermoelectric refrigeration or thermoelectric power generation, only the cold surface of the thermoelectric device can be bonded to the surface of the cooled object, or only the hot surface of the thermoelectric device can be bonded to the surface of the heat source. Since the temperature gradient direction of the flexible thermoelectric device with In-plane structure is parallel to the substrate plane, its hot surface and cold surface are on the same plane, which will lead to the inability to cool or generate electricity normally. Therefore, it is of great significance to carry out reasonable structural design to optimize the thermal distribution of the flexible thermoelectric device with In-plane structure to meet the requirements of thermoelectric refrigeration or thermoelectric power generation. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing an In-plane structure flexible thermoelectric device and a flexible thermoelectric device which can optimize the thermal distribution of the In-plane structure flexible thermoelectric device and can be used for thermoelectric cooling or thermoelectric power generation on a geometric surface with complex curvature changes.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing an In-plane structure flexible thermoelectric device, comprising:

[0006] S1. Designing structural parameters of the device, wherein the structural parameters of the device include the length of the thermoelectric arm, the width of the thermoelectric arm, and the spacing between the thermoelectric arms;

[0007] S2, preparing a P-type thermoelectric film and an N-type thermoelectric film;

[0008] S3, cutting and shaping the P-type thermoelectric film and the N-type thermoelectric film according to the structural parameters of the device to obtain a P-type thermoelectric film unit and an N-type thermoelectric film unit;

[0009] S4, bonding the P-type thermoelectric film units and the N-type thermoelectric film units side by side and staggered on the flexible substrate to form thermoelectric arms arranged at intervals;

[0010] S5, preparing a connecting electrode between two adjacent thermoelectric arms to form a head-to-tail connection pattern;

[0011] S6, preparing wires on the thermoelectric arms at both ends along the width direction of the thermoelectric film;

[0012] S7, pasting a flexible insulation layer on the flexible substrate pasted with the thermoelectric film unit to obtain a flexible device;

[0013] S8, folding the flexible device in half along a center line perpendicular to the length direction of the thermoelectric film, and pressing and forming the flexible thermoelectric device preform;

[0014] S9. Surface packaging is performed on the flexible thermoelectric device preform to obtain a flexible thermoelectric device with an In-plane structure in which the hot surface and the cold surface are in vertical directions.

[0015] Furthermore, in step S8, a hot melt adhesive film is placed between the folded flexible insulation layers, and the flexible device is pressed into shape by hot pressing.

[0016] Furthermore, in step S8, the flexible device is pressed into shape by hot pressing at a pressure of 5-15 MPa, a temperature of 100-150° C., and a time of 5-10 min.

[0017] Furthermore, in step S9, the flexible thermoelectric device preform is sealed and protected around four sides by a sealing material.

[0018] Furthermore, the sealing material is a sealing tape.

[0019] Furthermore, in step S2, the P-type thermoelectric film and the N-type thermoelectric film can be prepared by magnetron sputtering, chemical vapor deposition, pulsed laser deposition, molecular beam epitaxy, inkjet printing or electrospinning.

[0020] Furthermore, in step S5, the metal is prepared into a connecting electrode by mask vacuum evaporation method.

[0021] Furthermore, in step S5, conductive silver paste or conductive tin paste is prepared into connecting electrodes by a brushing method.

[0022] Furthermore, the flexible substrate is one of polyimide, polyethylene terephthalate, polyethylene naphthalate or silica gel; the flexible thermal insulation layer is one of diene flexible thermal insulation material, silica flexible thermal insulation material, nano aerogel thermal insulation material or flexible rubber.

[0023] The present invention also relates to a flexible thermoelectric device, which is prepared by any one of the preparation methods described above.

[0024] The beneficial effects of the present invention are: providing a method for preparing a flexible thermoelectric device, wherein a P-type thermoelectric film and an N-type thermoelectric film are alternately bonded side by side on a flexible substrate according to pre-designed structural parameters, and connecting electrodes are prepared between the P-type thermoelectric film and the N-type thermoelectric film, and then two copper wires are led out, and then a flexible insulation layer is pasted on the upper surface to obtain a flexible device, and then the flexible device is folded in half along a center line perpendicular to the length direction of the thermoelectric film, and pressed and formed, and finally surface packaged to obtain a flexible thermoelectric device. This method adds a flexible insulation layer to the upper surface of the In-plane structure flexible thermoelectric film, and folds it in half, thereby forming an In-plane structure flexible thermoelectric device with a hot surface and a cold surface in a vertical direction, optimizes the thermal distribution of the In-plane structure flexible thermoelectric device, and can be used for thermoelectric cooling or thermoelectric power generation of geometric surfaces with complex curvature changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The specific process and structure of the present invention are described in detail below with reference to the accompanying drawings:

[0026] Figure 1 It is a flow chart of the method for preparing the In-plane structure flexible thermoelectric device of the present invention;

[0027] Figure 2 It is a schematic diagram of the axial structure of the In-plane structure flexible thermoelectric device of the present invention;

[0028] Figure 3 It is a schematic diagram of the side structure of the In-plane structure flexible thermoelectric device of the present invention when it is not folded;

[0029] Figure 4 It is a schematic diagram of the side structure of the In-plane structure flexible thermoelectric device of the present invention after being folded;

[0030] Figure 5It is a schematic diagram of the side structure of the In-plane structure flexible thermoelectric device of the present invention after being pressed and formed;

[0031] Figure 6 This is a schematic diagram of the side structure of the In-plane structure flexible thermoelectric device of the present invention after surface packaging is completed;

[0032] 1-flexible substrate; 2-P-type thermoelectric film unit; 3-N-type thermoelectric film unit; 4-connecting electrodes; 5-leading wires; 6-flexible insulation layer; 7-hot melt adhesive film; 8-sealing material. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0038] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0039] Example

[0040] See also Figures 1 to 6 This embodiment provides a method for preparing an In-plane structure flexible thermoelectric device, comprising:

[0041] S1. Designing structural parameters of the device, wherein the structural parameters of the device include the length of the thermoelectric arm, the width of the thermoelectric arm, and the spacing between the thermoelectric arms;

[0042] S2, preparing a P-type thermoelectric film and an N-type thermoelectric film;

[0043] P-type thermoelectric film and N-type thermoelectric film can be prepared by magnetron sputtering, chemical vapor deposition, pulsed laser deposition, molecular beam epitaxy, inkjet printing or electrospinning. The thickness of the thermoelectric film is flexibly determined by different preparation processes. Depending on the process, the thickness of the P-type thermoelectric film and N-type thermoelectric film can be 1-50μm.

[0044] Among them, the P-type thermoelectric film can be a P-type Bi 2 Te 3 , one of P-type PbTe, P-type SiGe alloy, P-type oxide thermoelectric material, P-type Fanggu mine thermoelectric material or P-type Zintl compound;

[0045] The N-type thermoelectric film can be an N-type Bi 2 Te3 , N-type PbTe, N-type SiGe alloy, N-type oxide thermoelectric material, N-type ancient mineral thermoelectric material or N-type Zint l compound.

[0046] S3, cutting and shaping the P-type thermoelectric film and the N-type thermoelectric film according to the structural parameters of the device to obtain a P-type thermoelectric film unit 2 and an N-type thermoelectric film unit 3;

[0047] According to the designed structural parameters of the device, the P-type thermoelectric film and the N-type thermoelectric film are cut into strip-shaped thermoelectric film units with a length of 40-60 mm and a width of 2-10 mm for standby use.

[0048] S4, bonding the P-type thermoelectric film unit 2 and the N-type thermoelectric film unit 3 side by side and staggered on the flexible substrate 1 to form thermoelectric arms arranged at intervals;

[0049] Along the width direction of the strip thermoelectric film unit, the P-type thermoelectric film unit 2 and the N-type thermoelectric film unit 3 are arranged in a staggered manner on the flexible substrate 1 in the form of a P-type thermoelectric film unit 2, an N-type thermoelectric film unit 3, a P-type thermoelectric film unit 2, and an N-type thermoelectric film unit 3 to form thermoelectric arms arranged at intervals, and the distance between the edges of two adjacent thermoelectric arms is 2-5 mm.

[0050] The flexible substrate 1 is a flexible polymer material with good flexibility and thermal conductivity, such as polyimide, polyethylene terephthalate, polyethylene naphthalate, silica gel, etc. The thickness of the flexible substrate is preferably 0.05-1 mm.

[0051] Before bonding the thermoelectric film unit to the flexible substrate 1 , a step of cleaning the flexible substrate 1 is also included to ensure the reliability of bonding between the thermoelectric film unit and the flexible substrate 1 .

[0052] S5, preparing a connecting electrode 4 between two adjacent thermoelectric arms to form a head-to-tail connection mode;

[0053] A connecting electrode 4 is prepared between two adjacent thermoelectric arms in such a way that the tail end of a P-type thermoelectric film unit 2 is connected to the head end of an N-type thermoelectric film unit 3, and the tail end of the N-type thermoelectric film unit 3 is connected to the head end of another P-type thermoelectric film unit 2, forming a head-to-tail connection mode, thereby realizing electrical series connection between the thermoelectric film units.

[0054] The method of preparing the connection electrode can be to prepare the metal into the connection electrode 4 by mask vacuum evaporation method. Specifically, a mask plate is covered on the flexible substrate 1 with the thermoelectric film unit attached thereto, and the mask plate is provided with openings corresponding to the positions where the connection electrode needs to be prepared. The metal is plated at the positions where the connection electrode needs to be prepared by vacuum evaporation method. Preferably, the metal is one of silver, copper and aluminum;

[0055] The connection electrode can also be prepared by brushing conductive silver paste or conductive tin paste to form the connection electrode 4. Specifically, the conductive silver paste or conductive tin paste is coated on the position where the connection electrode needs to be prepared, thereby completing the preparation of the connection electrode.

[0056] S6, preparing wires 5 on the thermoelectric arms at both ends along the width direction of the thermoelectric film;

[0057] The wires 5 are welded to the thermoelectric arms at both ends by soldering to form a positive wire and a negative wire. The positive wire and the negative wire are made of one of silver, copper and aluminum.

[0058] S7, pasting a flexible insulation layer 6 on the flexible substrate 1 pasted with the thermoelectric film unit to obtain a flexible device;

[0059] In order to avoid heat exchange between the two planes of the hot end and the cold end, which affects the working efficiency of the thermoelectric device, a flexible insulation layer 6 is pasted on the flexible substrate 1 with the thermoelectric film unit pasted thereon, which can effectively prevent heat exchange between the two planes.

[0060] Preferably, the flexible thermal insulation layer 6 is one of diene flexible thermal insulation material, silicon dioxide flexible thermal insulation material, nano aerogel thermal insulation material or flexible rubber.

[0061] S8, folding the flexible device in half along a center line perpendicular to the length direction of the thermoelectric film, and pressing and forming the flexible thermoelectric device preform;

[0062] In order to obtain an In-plane structure flexible thermoelectric device with the hot surface and the cold surface in a vertical direction, the flexible device is folded in half along the center line L perpendicular to the length direction of the thermoelectric film. At the same time, in order to maintain the stability and reliability of the structure, a hot melt adhesive film 7 is placed between the folded flexible insulation layers, and the flexible thermoelectric device is pressed into shape by hot pressing, so as to obtain the following Figure 4 The flexible thermoelectric device preform shown has an upper surface as a cold end and a lower surface as a hot end.

[0063] The hot pressing pressure of the flexible thermoelectric device pressed into shape by hot pressing is 5-15MPa, the hot pressing temperature is 100-150°C, and the hot pressing time is 5-10min.

[0064] By subjecting the flexible thermoelectric device to heat pressing treatment, the hot surface and the cold surface of the flexible thermoelectric device can be kept in a vertical position.

[0065] S9. Surface packaging is performed on the flexible thermoelectric device preform to obtain a flexible thermoelectric device with an In-plane structure in which the hot surface and the cold surface are in vertical directions.

[0066] In order to prevent external water vapor from corroding and damaging the flexible thermoelectric device, the flexible thermoelectric device preform needs to be surface-encapsulated, leaving only the positive and negative electrode wires. Specifically, the flexible thermoelectric device preform can be sealed and protected around by a sealing material 8, wherein the sealing material 8 is a sealing tape.

[0067] By attaching the sealing tape around the flexible thermoelectric device, the flexible thermoelectric device is sealed and protected all around, effectively preventing the entry of foreign matter and water vapor, and ensuring the service life of the flexible thermoelectric device.

[0068] From the above description, it can be seen that the beneficial effects of the present invention are: providing a method for preparing a flexible thermoelectric device, bonding a P-type thermoelectric film and an N-type thermoelectric film alternately side by side on a flexible substrate according to pre-designed structural parameters, preparing connecting electrodes between the P-type thermoelectric film and the N-type thermoelectric film, then leading out two copper wires, and then pasting a flexible insulation layer on the upper surface to obtain a flexible device, and then folding the flexible device along a center line perpendicular to the length direction of the thermoelectric film, and pressing and forming, and finally performing surface packaging to obtain a flexible thermoelectric device. This method adds a flexible insulation layer to the upper surface of the In-plane structure flexible thermoelectric film and folds it in half, thereby forming an In-plane structure flexible thermoelectric device with a hot surface and a cold surface in a vertical direction, optimizes the thermal distribution of the In-plane structure flexible thermoelectric device, and can be used for thermoelectric cooling or thermoelectric power generation of geometric surfaces with complex curvature changes.

[0069] The present invention also relates to a flexible thermoelectric device, which is prepared by the preparation method as described above.

[0070] It is easy for those skilled in the art to understand that the above-mentioned implementation modes can be freely combined and superimposed without conflict.

[0071] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing an In-plane structure flexible thermoelectric device, comprising: S1. Designing structural parameters of the device, wherein the structural parameters of the device include the length of the thermoelectric arm, the width of the thermoelectric arm, and the spacing between the thermoelectric arms; S2, preparing a P-type thermoelectric film and an N-type thermoelectric film; S3, cutting and shaping the P-type thermoelectric film and the N-type thermoelectric film according to the structural parameters of the device to obtain a P-type thermoelectric film unit and an N-type thermoelectric film unit; S4, bonding the P-type thermoelectric film units and the N-type thermoelectric film units side by side and staggered on the flexible substrate to form thermoelectric arms arranged at intervals; S5, preparing a connecting electrode between two adjacent thermoelectric arms to form a head-to-tail connection pattern; S6, preparing wires on the thermoelectric arms at both ends along the width direction of the thermoelectric film; S7, pasting a flexible insulation layer on the flexible substrate pasted with the thermoelectric film unit to obtain a flexible device; S8, folding the flexible device in half along a center line perpendicular to the length direction of the thermoelectric film, and pressing and forming the flexible thermoelectric device preform; S9. Surface packaging is performed on the flexible thermoelectric device preform to obtain a flexible thermoelectric device with an In-plane structure in which the hot surface and the cold surface are in vertical directions.

2. The preparation method according to claim 1, characterized in that: In step S8, a hot melt adhesive film is placed between the folded flexible insulation layers, and the flexible device is pressed into shape by heat pressing.

3. The preparation method according to claim 2, characterized in that: In step S8, the flexible device is pressed into shape by hot pressing at a pressure of 5-15 MPa, a temperature of 100-150° C., and a time of 5-10 min.

4. The preparation method according to claim 1, characterized in that: In step S9, the flexible thermoelectric device preform is sealed and protected around four sides by a sealing material.

5. The preparation method according to claim 4, characterized in that: The sealing material is a sealing tape.

6. The preparation method according to claim 1, characterized in that: In step S2 , the P-type thermoelectric film and the N-type thermoelectric film may be prepared by magnetron sputtering, chemical vapor deposition, pulsed laser deposition, molecular beam epitaxy, inkjet printing or electrostatic spinning.

7. The preparation method according to claim 1, characterized in that: In step S5, metal is prepared into connecting electrodes by mask vacuum evaporation method.

8. The preparation method according to claim 1, characterized in that: In step S5, conductive silver paste or conductive tin paste is prepared into connecting electrodes by a brushing method.

9. The preparation method according to claim 1, characterized in that: The flexible substrate is one of polyimide, polyethylene terephthalate, polyethylene naphthalate or silica gel; the flexible thermal insulation layer is one of diene flexible thermal insulation material, silicon dioxide flexible thermal insulation material, nano aerogel thermal insulation material or flexible rubber.

10. A flexible thermoelectric device, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 9.

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