Thermoelectric conversion module and method for manufacturing thermoelectric conversion module

Abstract

To provide thermoelectric conversion modules capable of dealing with such as a wide surface or a curved surface, and also to provide methods of manufacturing such thermoelectric conversion modules.SOLUTION: There is provided, a photoelectric conversion module 101 in which a metal layer 2 and a conductive polymer layer 1 are alternately stacked without gaps therebetween; an insulating layer 3 and an electrode layer 4, and an insulating layer 3 and an electrode layer 5 are joined on both faces of the conductive polymer layer 1, respectively; the electrode layers 4, 5 are located respectively on a first end side of a first face of the conductive polymer layer 1 and a second end side of a second face on an opposing side of the first end side; and the conductive polymer layer 1 and the metal layer 2 are electrically connected via the electrode layer 4 or the electrode layer 5. The metal layer 2, the conductive polymer layer 1, the insulating layer 3, and the electrode layers 4, 5 are laminated to be step-like overall. In addition, provided is a method of manufacturing a thermoelectric conversion module, in which, when a metal layer 2, an insulating layer 3 and a conductive polymer layer 1 are laminated to manufacture a thermoelectric conversion module 101, these layers are laminated to be step-like overall.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a thermoelectric conversion module, and more specifically to a thermoelectric conversion module using a conductive polymer as a thermoelectric material, and a method for manufacturing the thermoelectric conversion module. [Background technology]

[0002] Thermoelectric conversion is a technology that directly converts thermal energy into electrical energy and vice versa using a solid-state thermoelectric conversion module. The technology that converts thermal energy into electrical energy is called thermoelectric generation, and is based on the Seebeck effect, which is one of the thermoelectric effects. In thermoelectric generation, the temperature difference between both ends of the thermoelectric conversion module is directly converted into electrical energy.

[0003] Thermoelectric conversion using organic materials has attracted attention as an energy harvesting technology that recovers low-temperature waste heat due to its light weight and simple manufacturing method. Conductive polymers, in particular, have the advantages of being lightweight, flexible, non-toxic, inexpensive, and requiring little manufacturing energy. Furthermore, the manufacturing process offers the advantages of mass production, large-area production, and low cost, making them promising materials for application in electrical and electronic components.

[0004] For example, Patent Documents 1 and 2 below disclose a thermoelectric conversion module in which a plurality of films, such as PEDOT / PSS (poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonic acid)), which is a conductive polymer, are laminated, along with insulating films and metal films. This thermoelectric conversion module has a heat source disposed on one side of the laminated structure, and generates electricity from the temperature difference between one side and the other side. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-27061 [Patent Document 2] Patent No. 6781982 Summary of the Invention [Problem to be solved by the invention]

[0006] In such a thermoelectric conversion module, the sides of the laminated structure are close to the heat source, and power is obtained from a relatively narrow plane. In recent years, there has been a demand for thermoelectric conversion modules to be used in a variety of environments, and in response to modern demands, there is a demand for higher performance and for further expansion of applications, for example, to accommodate larger or curved surfaces.

[0007] Therefore, an object of the present invention is to provide a thermoelectric conversion module that can be adapted to a larger surface or a curved surface, and to provide a method for manufacturing such a thermoelectric conversion module. [Means for solving the problem]

[0008] The thermoelectric conversion module described above can obtain power from a relatively narrow flat surface because the sides of the laminated structure are close to the heat source. However, the present inventors have discovered that by devising the laminated structure of the thermoelectric conversion module, it is possible to accommodate a wide surface or a curved surface.

[0009] One embodiment of the present invention is a thermoelectric conversion module in which metal layers and conductive polymer layers are alternately stacked without any gaps, insulating layers and electrode layers are bonded to both sides of the conductive polymer layer, the electrode layers are located on a first end side of a first surface of the conductive polymer layer and on a second end side of a second surface opposite the first end side, and the conductive polymer layers and the metal layers are electrically connected via the electrode layers, and the metal layers, the conductive polymer layers, the insulating layers, and the electrode layers are stacked in a stepped manner overall in this thermoelectric conversion module.

[0010] Furthermore, one embodiment of the present invention is a method for manufacturing a thermoelectric conversion module by stacking metal layers, insulating layers, and conductive polymer layers to manufacture a thermoelectric conversion module, the method comprising the steps of: forming electrode layers on both sides of the metal layer so that, when stacked, they are located at a first end side of a first surface of the conductive polymer layer and at a second end side of a second surface opposite the first end side; or forming electrode layers on the first end side of the first surface of the conductive polymer layer and at a second end side of the second surface opposite the first end side; and stacking the conductive polymer layer and the metal layer alternately and without gaps, with the insulating layer sandwiched between them, so that the conductive polymer layer and the metal layer are electrically connected via the electrode layer; and in the stacking step, the metal layer, insulating layer, and conductive polymer layer are stacked so as to form a stepped configuration overall. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a thermoelectric conversion module that can be adapted to a wide surface or a curved surface, etc. It is also possible to provide a method for manufacturing such a thermoelectric conversion module. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a configuration diagram illustrating the power generation principle of a thermoelectric conversion module. [Figure 2] 1A and 1B are a side view and a plan view showing the configuration of a thermoelectric conversion module of the present embodiment. [Figure 3] FIG. 2 is a plan view of each component of the thermoelectric conversion module. [Figure 4] 10 is another example showing the configuration of a thermoelectric conversion module. [Figure 5] 10 is another example showing the configuration of a thermoelectric conversion module. [Figure 6] 1 is a photograph of a thermoelectric conversion module. [Figure 7] FIG. 2 is a schematic diagram illustrating a method for evaluating a thermoelectric conversion module. [Figure 8] FIG. 4 is a diagram showing the relationship between the temperature difference and the voltage of a thermoelectric conversion module. DETAILED DESCRIPTION OF THE INVENTION

[0013] (Power generation principle of thermoelectric conversion modules) FIG. 1 is a structural diagram illustrating the power generation principle of a thermoelectric conversion module. This thermoelectric conversion module 100 has a structure in which conductive polymer layers 1 and metal layers 2 are alternately stacked. The conductive polymer layers 1 are made of a material with a rectangular surface and thermoelectric properties. The metal layers 2 are made of a metal for electrical connection. Therefore, a thermoelectric conversion module according to one embodiment of the present invention has a structure in which thermoelectric materials (conductive polymer layers) and electrical connection materials (metal layers) are alternately stacked.

[0014] FIG. 1(b) shows details of the structure 10 including the region surrounded by an ellipse in FIG. 1(a), i.e., the metal layer 2 between two conductive polymer layers 1. As shown in this figure, an insulating layer 3 and electrode layers 4 and 5 are bonded to both sides of the metal layer 2. Note that, throughout this specification, these are sometimes collectively referred to as a bonding layer 12. The electrode layer 4 is located at one end of the front surface of the metal layer 2, and the electrode layer 5 is located at the other end of the back surface, opposite the one end. Note that, although there is a space between the insulating layer 3 and the electrode layers 4 and 5 and the conductive polymer layer 1 in FIG. 1(b), this is for clarity of illustration. In reality, the bonding layer 12, which is composed of the insulating layer 3 and the electrode layers 4 and 5, is also bonded to the adjacent conductive polymer layer 1. This also applies to the following embodiments.

[0015] 1(c) is an image diagram showing how a thermoelectric conversion module 100 in which multiple configurations of (b) are joined generates power through thermoelectric conversion. In this thermoelectric conversion module 100, conductive polymer layers 1 are arranged on both ends (outsides) of the thermoelectric conversion module 100, and bonding layers 12 and conductive polymer layers 1 are arranged alternately between them.

[0016] The thermoelectric conversion module 100 is heated by a heat source on its lower side (one side). A temperature difference between the lower and upper sides (the other side) creates a Seebeck effect, causing current to flow sequentially within the module as indicated by arrow 6, output to an external circuit, and dissipate heat from the upper side. The upper side of the module is naturally cooled or forcibly cooled. Within the module, current generated within the conductive polymer layer 1 flows upward through the electrode layer 4 to the adjacent metal layer 2. The current then flows downward within the metal layer 2 and then through the electrode layer 5 to the adjacent conductive polymer layer 1. This same current flow 6 is repeated, enabling the module to be used as a variety of power sources. Because the end of the stack of thermoelectric conversion modules 100 is in contact with the heat source, power is obtained from a relatively narrow plane.

[0017] (Embodiment) Next, the thermoelectric conversion module of this embodiment will be described. Fig. 2 is a side view and a plan view showing the configuration of a thermoelectric conversion module 101. Although not shown, conductive wires are connected to the edges of the upper and lower conductive polymer layers 1 using a conductive adhesive (not shown) or the like to extract electric power. Fig. 3 is a plan view of each component of the thermoelectric conversion module.

[0018] The thermoelectric conversion module 101 of this embodiment has a structure in which conductive polymer layers 1 and metal layers 2 are alternately laminated. In this case, the module is configured so that the conductive polymer layers 1 are disposed on both ends of the module. Note that both ends of the module may be made of insulating layers other than conductive polymer layers (electrode layers on one end side) or metal layers. Note that, when a numerical range is indicated in this specification, it is intended to include the upper and lower limits.

[0019] According to this embodiment, the conductive polymer layer 1, metal layer 2, insulating layer 3, etc. are stacked in a stepped manner, shifted in the direction of a line connecting one end and the other end of the conductive polymer layer where the electrode layers 4 and 5 are located, thereby enabling the device to be used on a wide surface. Each component will be described below.

[0020] The conductive polymer layer 1 is made of, for example, a PEDOT / PSS film. Polyaniline, carbon nanotubes (CNTs), etc. may also be used. PEDOT / PSS is a charge transfer complex composed of poly(3,4-ethylenedioxythiophen) (PEDOT) and poly(styrenesulfonate) (PSS). PEDOT / PSS has p-type thermoelectric properties. In PEDOT / PSS, PSS, which acts as a dopant, supplies carriers to PEDOT, resulting in good conductivity of PEDOT. Furthermore, as mentioned above, adding ethylene glycol (EG) during the deposition of the PEDOT / PSS film aligns the crystal orientation, improving the electrical conductivity of the deposited PEDOT / PSS film.

[0021] Specifically, when the conductive polymer layer 1 is a PEDOT / PSS film, it can be produced by the following method. A suitable amount of EG (a few percent) is mixed with the raw material reagent, placed in a mold, and heated (e.g., at 40°C) on a heater for a predetermined time (e.g., 24 hours) to evaporate the water. The film thickness can be adjusted by controlling the amount of EG added based on the bottom area of ​​the mold. The film thickness should be, for example, 10-50 μm. There is no lower limit to the film thickness, as long as it is possible to produce it and maintain its strength. A film thickness of this order meets the demands for high-performance and compact thermoelectric conversion modules, and also facilitates the production of thermoelectric conversion modules with sufficient strength. The film thickness can also be adjusted to the above range by compressing the film.

[0022] (metal layer) The metal layer 2 is made of, for example, a nickel (Ni) film. Other metals are not particularly limited, and examples include aluminum, iron, and copper. Alloys are also acceptable, including metal materials with high thermoelectric power, such as copper-nickel alloys and aluminum-nickel alloys. Since most metals have n-type thermoelectric properties, the metal layer 2 is preferably made of a metal with high n-type thermoelectric properties, such as Ni, for not only electrical connection in module configuration. The metal layer 2 may be rectangular, like the conductive polymer layer 1, but preferably has an I-shaped surface (Figure 3). The I-shaped metal layer 2 has the highest thermal conductivity, so it minimizes contact resistance between the metal layer 2 and the conductive polymer layer 1 while simultaneously minimizing thermal conduction to increase the temperature difference ΔT between the left and right. The film thickness is preferably 5-10 μm to minimize thermal conduction.

[0023] (insulating layer and electrode layer) The insulating layer 3 can be made of, for example, an insulating polymer. Examples of insulating polymers that can be used include insulating polyimide film. Other materials include fluororesin film, acetate film, PET film, and epoxy film. However, polyimide film is preferred because it is thin, strong, and heat-resistant. The electrode layers 4 and 5 can be made of gold (Au), platinum (Pt), silver (Ag), graphite (C), or copper (Cu). More preferably, Au or Pt, which have low contact resistance and are resistant to oxidation, can be used for the electrode layers 4 and 5. The thinner the insulating layer 3, the better, with a thickness of 5-10 μm being preferred. For example, insulating polyimide films with a thickness of 5 μm are commercially available and easily available. The electrode layers 4 and 5 can be made to any thickness that ensures conductivity. However, in the case of gold vapor deposition, a thickness of approximately 20 nm is recommended to ensure uniform surface coverage.

[0024] Furthermore, the insulating layer 3 and the electrode layer 4 (or electrode layer 5) are bonded to adjacent conductive polymer layers 1. Therefore, when viewed from the inner surfaces of the two conductive polymer layers 1, the electrode layer 4 is located at one end of the surface of one conductive polymer layer 1, and the electrode layer 5 is located at the other end opposite to the one end of the surface of the other conductive polymer layer 1. As a result, the conductive polymer layer 1 and the metal layer 2 are electrically connected in series via the electrode layers 4 and 5.

[0025] (Laminated structure) According to this embodiment, as shown in Fig. 2, a conductive polymer layer 1 is first placed, and then a required number of units 11 each composed of an insulating layer 3, a metal layer 2, another insulating layer 3, a conductive polymer layer 1, etc. are stacked in a stepped pattern on top of the conductive polymer layer 1, thereby achieving a compact thermoelectric conversion module while keeping the height low. Note that since the entire rectangular surface of the conductive polymer layer 1 is conductive, electrical loss can be reduced by stacking members placed on the conductive polymer layer 1 in a stepped pattern with a shift.

[0026] In addition, as an example of stacking in a stepped manner, each layer, multiple layers, or a combination of these may be stacked in a stepped manner. Furthermore, units consisting of multiple layers and single layers may be stacked alternately, regularly, or randomly in a stepped manner. That is, it is sufficient that these layers are stacked in a stepped manner overall. In the example of FIG. 2, a single unit 11 is configured by stacking an insulating layer 3 (electrode layer 4 or electrode layer 5), a metal layer 2, an insulating layer 3, and a conductive polymer layer 1. However, there are various combinations of layers that constitute a unit, such as a single unit configured by stacking an insulating layer 3, a metal layer 2, and an insulating layer 3 (bonding layer 12) or a single unit configured by stacking an insulating layer 3 and a conductive polymer layer 1. For example, when electrode layers 4 and 5 are vapor-deposited on a metal layer 2, it is preferable to use a single unit consisting of the bonding layer 12, as this facilitates fabrication.

[0027] Figure 4 shows another example of a thermoelectric conversion module. Figure 4(A) shows an example in which units 13 and single-layer metal layers 2 are alternately stacked, and Figure 4(B) shows an example in which units 15 are stacked. When electrode layers 4 and 5 are vapor-deposited on a conductive polymer layer 1, such a unit structure is easy to fabricate and is preferable. Furthermore, compared to when each layer (each component) is slightly shifted, the flexibility of the entire module is not affected even if only a few layers (several sheets) are left stacked, and from the standpoint of workability, it is preferable to shift each unit as shown in Figures 2 and 4. In any case, it is sufficient that the conductive polymer layer 1 and the metal layer 2 are electrically connected in series via the electrode layers 4 and 5.

[0028] According to this embodiment, the thermoelectric conversion module is not stacked evenly, but rather stacked in a stepped manner, resulting in a longer, planar structure, enabling power generation from a heat source with a wide surface area. Furthermore, the reduced thickness of the thermoelectric conversion module allows it to be adapted to curved surfaces. In particular, when flexible materials such as thin films are used as components of the thermoelectric conversion module, they can easily fit curved surfaces and generate power efficiently. Note that flexibility refers to the property of easily deforming when external force is applied, for example, with a finger. By using flexible films such as a PEDOT / PSS film on the order of 10 microns as the conductive polymer layer 1, an insulating film on the order of several microns to several 10 microns as the insulating layer 3, or a metal film on the order of several microns to several 10 microns as the metal layer 2, the thermoelectric conversion module can be wrapped around a human arm, a pipe, or the like.

[0029] (Method of manufacturing thermoelectric conversion module) The following provides an overview of a method for manufacturing the thermoelectric conversion module 101 according to one embodiment of the present invention shown in Fig. 2. The following method will be described using an example in which a PEDOT / PSS film is used as the conductive polymer layer 1, an I-type Ni film is used as the metal layer 2, an insulating polyimide film is used as the insulating layer 3, and gold (Au) is used as the electrode layers 4 and 5. (a) Prepare a PEDOT / PSS film of a predetermined size, an insulating polyimide film (shortened in length by the size of the Au), and an I-type Ni film. The thickness of the PEDOT / PSS film can be adjusted using the method described above. The film thickness can be adjusted during film formation, or by compressing the film after formation. (b) Au is applied to predetermined locations (edges) on both the front and back of the I-type Ni film to reduce contact resistance (this can be done by vacuum deposition or by applying a paste or the like). (c) Stack the required number of each component and sandwich them between plates. The stacking order is as shown in Figure 2, with each unit offset by a length W1. The polyimide films are stacked alternately so that the PEDOT / PSS and Ni contact each other via the Au. (d) The laminate is heated and pressed in a heat press to set the shape (50°C, 50 kgf, approximately 60 minutes). (e) Conductive wires are connected to the edges of the upper and lower PEDOT / PSS films of the laminate using a conductive adhesive or by crimping, and power is extracted. In this specification, the laminate is also referred to as a thermoelectric conversion module. In step (b), Au is applied to the Ni film, but Au may also be applied to both sides of the PEDOT / PSS film.

[0030] In step (c), the longer the offset length W1, the lower the stack height and the greater the flexibility. However, the shorter the length W2 that creates the effective temperature difference (e.g., about 5 K), the smaller the available temperature difference ΔT, resulting in a decrease in output. Therefore, the offset length W1 should be set to a length that can maintain an effective temperature difference that can provide a certain level of output. Note that the offset lengths of the individual layers may not be the same, but may be different. While FIG. 2(B) shows a plan view of the thermoelectric conversion module 101, the modules may be stacked not only by being offset horizontally in a straight line, but also by being offset diagonally as shown in FIG. 5. This offset makes it easier to wrap the modules in a spiral, particularly around a person's arm or a pipe.

[0031] In the example of thermoelectric conversion module 101 shown in Fig. 2, both ends of the thermoelectric conversion module are made of conductive polymer layers 1, so the conductive polymer layer 1 is first arranged, and then the required number of insulating layers 3, metal layers 2, insulating layers 3, and conductive polymer layers 1 are laminated on top of that in this order. On the other hand, if both ends of the thermoelectric conversion module are not made of conductive polymer layers 1, or if only one end of the thermoelectric conversion module is made of conductive polymer layers 1 (various structures are included), or if the arrangement of components differs from that of thermoelectric conversion module 100 shown in Fig. 2, the order in which these components are laminated can be changed.

[0032] In the thermoelectric conversion module 101 of this embodiment, current generated within the module due to the Seebeck effect flows sequentially as indicated by arrow 6, is output to an external circuit, and heat is dissipated from the left side. The left side of the module is naturally cooled or forcedly cooled. Within the module, current generated within the conductive polymer layer 1 flows into the adjacent metal layer 2 via the electrode layer 4 that is attached to it. The current flows through the metal layer 2 and then flows into the adjacent conductive polymer layer 1 via the electrode layer 5 that is attached to it. Similar current flow 6 is repeated thereafter, enabling use as a power source for various IoT applications, such as Bluetooth signals, various sensors used in mobile objects such as automobiles, or health monitors and location information transmitters for humans and animals. Heat sources can include various sources, such as factory waste heat, equipment waste heat, exhaust pipes, drainage pipes, household waste heat, the human body, animals, geothermal heat, and solar heat. [Example]

[0033] A PEDOT / PSS film was formed by mixing a few percent of EG (Fujifilm Wako Chemical Co., Ltd.) with the raw material reagent (Heraeus Clevios-PH1000). The mixture was placed in a mold (AS ONE Corporation, ABS non-charged rectangular case-10 type) and heated on a heater at 40°C for 24 hours to evaporate the water. The film thickness was adjusted to 50 μm by controlling the amount of material added based on the bottom area of ​​the mold. Furthermore, Ni foil (Nilaco Corporation, NI-313133, 5 μm (thickness) × 100 × 300 mm) was used as the I-type Ni film. Au (Tanaka Kikinzoku Kogyo Co., Ltd., Au particles, sapling-shaped, purity 99.99% or higher) was deposited on both the front and back edges of the I-type Ni film using a vapor deposition apparatus (Vacuum Device Co., Ltd., VE-2012) at a vacuum level of 5 × 10°C. -3 The deposition was carried out at 100 Pa for 5 minutes. The current value at that time was approximately 12-14 A. The deposited Au film thickness was approximately 20 nm. Furthermore, a roll of film (Toray Industries, Inc., Kapton (registered trademark), 20EN, 5 μm (thickness) × 508 mm × 20 m) was used as the insulating polyimide film. The PEDOT / PSS film, Ni foil, and insulating polyimide film were formed into a predetermined size using a die-cutting punch. The PEDOT / PSS film and Ni foil were formed into a 22 mm × 22 mm rectangle, and the Ni foil was cut into an I-shape.

[0034] These components were stacked in groups of four (5 PEDOT / PSS films, 4 Ni foils, and 8 insulating polyimide films) with a 3 mm offset between them as shown in Figure 2. The stacked components were then sandwiched between fluororesin (Teflon®) plates (1 mm thick, 15 cm x 10 cm) and heated and pressed in a heat press (50°C, 50 kgf, 60 minutes) to form a uniform shape. The fabricated thermoelectric conversion module 101 measured 0.28 mm (thickness) x 2.2 cm x 3.4 cm, weighed 0.21 g, and had a resistance of 3-4 Ω.

[0035] Figure 6 shows a photograph of the fabricated thermoelectric conversion module 101. By stacking the layers that make up the thermoelectric conversion module in a stepped manner as shown in Figure 2, the module becomes longer in plan view, making it possible to obtain electricity from a heat source with a wide surface area. Furthermore, if flexible materials such as thin films are used as components of the thermoelectric conversion module, they are particularly suitable for use on curved surfaces. Furthermore, by increasing the number of layers, it is possible to fabricate a thermoelectric conversion module 101 in a ring or spiral shape, which can be wrapped around a person's arm or a pipe, thereby expanding the range of uses.

[0036] Figure 7 shows a schematic diagram explaining the evaluation method for thermoelectric conversion module 101, and Figure 8 shows the relationship between the temperature difference and voltage of thermoelectric conversion module 101. When the components are stacked so that they completely overlap in a planar view (viewed from the top surface of the layers) (Figure 1), the Seebeck coefficient of PEDOT / PSS is 18 μV / K and the Seebeck coefficient of Ni is 20 μV / K. Therefore, when five PEDOT / PSS films and four Ni foils are used to fabricate a module, an output voltage of approximately 170 μV / K can be expected according to the following calculation formula. The Seebeck coefficient is the thermoelectric power at 1 K per sheet. (18×5)+(20×4)=170(μV / K) The thermoelectric conversion module 101 produced by the above method was sandwiched between the upper Peltier 21 and the lower Peltier 23 via a spacer 25, as shown in Figure 7, and electricity was passed through each of the upper Peltier 21 and the lower Peltier 23 to adjust the temperature difference between the upper and lower Peltiers, and the voltage was measured. The measurement conditions are as follows.

[0037] The temperatures of the Peltier elements (UT70U100F-S16, manufactured by Ampere Corporation) on the high-temperature and low-temperature sides were adjusted using a temperature controller (UTC-200A, manufactured by Ampere Corporation). The voltage (thermoelectromotive force from the module) was measured using a measuring device (LR8400, data logger, manufactured by Hioki E.E. Corporation). The temperature was changed by 1°C above and below the set temperature of 25°C, and measurements were taken at five points to evaluate the thermoelectromotive force. Specifically, measurements were taken at five temperature differences: 2°C (upper: 26°C, lower: 24°C), 4°C (27°C-23°C), 6°C (28°C-22°C), 8°C (29°C-21°C), and 10°C (30°C-20°C).

[0038] Because there is a difference between the set temperature and the actual temperature of the module, the horizontal axis of Figure 8 shows the temperature difference calculated from the temperatures measured with the R thermocouples (Ishikawa Sangyo Co., Ltd., ultra-fine thermocouple wire, Type R, wire diameter φ0.1 mm, length 200 mm) attached to both ends of the module, and the vertical axis shows the resulting thermoelectromotive force. The temperature of the R thermocouple was also measured using a measuring device (Hioki E.E. Corporation, data logger, LR8400) in the same way as the thermoelectromotive force. Furthermore, the voltage (thermoelectromotive force) generated between the platinum wires of each R thermocouple used to measure the temperature at the two high-temperature and low-temperature points was measured. In consideration of errors, three identical thermoelectric conversion modules 101 were fabricated and each was measured.

[0039] The results are shown in Figure 8. The results for the same thermoelectric conversion module are shown with the same symbols. In this example, by stacking the units 11, which are components of the thermoelectric conversion module 101, in a tiered fashion, the effective temperature difference is reduced, resulting in a smaller output voltage than when the units are stacked so that they are all overlapping (Figure 1) (170 μV / K). However, the output voltage of three thermoelectric conversion modules was approximately 144-146 μV / K, and the average for the three thermoelectric conversion modules was 145 μV / K, indicating that the decrease was limited to approximately 15%. Therefore, it was confirmed that the voltage decrease when stacked in tiers is small and is suitable for practical use. Furthermore, the output voltage can be easily increased by adjusting the number of layers.

[0040] Furthermore, the electrical resistance of the thermoelectric conversion module was approximately 4.0-5.0 Ω for five PEDOT / PSS films, since the resistance per film was 0.8-1.0 Ω. This resistance was calculated assuming that all components were stacked so that they overlapped in a planar view, as shown in Figure 1. In this example, as shown in Figure 8, the resistances for three modules were 4.0 Ω, 5.0 Ω, and 6.0 Ω, respectively, which were roughly the same as the calculated values. While stacking units with offsetting the resistance would be expected to increase due to poor contact between the layers, this example did not result in an increase in resistance, and it was confirmed that the performance of the offset stacking was equivalent to that of the aligned stacking. [Industrial Applicability]

[0041] The thermoelectric conversion module according to the present invention can be used as a power source for various IoT applications, such as a power source for Bluetooth signals, a power source for various sensors used in mobile objects such as automobiles, or a power source for health monitors and location information transmitters for humans and animals. [Explanation of symbols]

[0042] 1 Conductive polymer layer 2 metal layer 3. Insulation layer 4, 5 electrode layer 6 Arrow indicating the direction of current 11, 13, 15 units 12 Bonding layer 21 Upper Berthia 23 Lower Berthia 25 spacer 100, 101 Thermoelectric conversion module

Claims

1. Metal layers and conductive polymer layers are alternately laminated, an insulating layer and an electrode layer are bonded to both surfaces of the conductive polymer layer; the electrode layer is located on a first end side of a first surface of a conductive polymer layer and on a second end side of a second surface opposite to the first end side, the second surface facing the first surface, and the conductive polymer layer and the metal layer are electrically connected to each other via the electrode layer, the insulating layer and the electrode layer are adjacent to each other on the same plane, and the insulating layer is located on a second end side of the first surface of the conductive polymer layer and on a first end side of the second surface of the conductive polymer layer; the metal layer, the conductive polymer layer, and the insulating layer and electrode layer bonded to both surfaces of the conductive polymer layer form a repeated laminate structure as a unit; In the laminated structure, the conductive polymer layer, a first insulated electrode layer formed by the insulating layer and the electrode layer disposed on a first surface of the conductive polymer layer, a second insulated electrode layer formed by the insulating layer and the electrode layer disposed on a second surface of the conductive polymer layer, and the metal layer are configured to be shifted in an in-plane direction with respect to another repeating unit, Furthermore, in the laminated structure, the repeating units, which are the conductive polymer layer, a first insulated electrode layer formed by the insulating layer and the electrode layer disposed on a first surface of the conductive polymer layer, a second insulated electrode layer formed by the insulating layer and the electrode layer disposed on a second surface of the conductive polymer layer, and the metal layer, are configured so that the outer peripheries of each layer coincide in an in-plane direction.

2. Furthermore, in the laminated structure, the conductive polymer layer, a first insulated electrode layer formed by the insulating layer and the electrode layer disposed on a first surface of the conductive polymer layer, a second insulated electrode layer formed by the insulating layer and the electrode layer disposed on a second surface of the conductive polymer layer, and the metal layer, which constitute a repeating unit, form a composite layer in which the outer peripheries of the layers coincide in the in-plane direction, 2. The thermoelectric conversion module according to claim 1, wherein in a stacked structure in which the composite layers are stacked, in a plane perpendicular to the stacking direction, a surface corresponding to a predetermined surface forming the outer periphery of a predetermined composite layer of a composite layer other than the predetermined composite layer is located at a position shifted in a diagonal direction.

3. The thermoelectric conversion module according to claim 1 , wherein the conductive polymer layer includes a PEDOT / PSS film.

4. The thermoelectric conversion module according to claim 1 , wherein the metal layer, the conductive polymer layer, and the insulating layer are flexible.

5. A method for manufacturing a thermoelectric conversion module by laminating a metal layer, an insulating layer, and a conductive polymer layer, comprising: forming electrode layers on both surfaces of the metal layer so as to be located at a first end side of a first surface of the conductive polymer layer and at a second end side of a second surface opposite to the first end side when the layers are laminated, or forming electrode layers on the first end side of the first surface of the conductive polymer layer and at a second end side of a second surface opposite to the first end side; a step of alternately stacking the conductive polymer layers and the metal layers with the insulating layer sandwiched therebetween so that the conductive polymer layers and the metal layers are electrically connected via the electrode layer; Equipped with In the laminating step, the insulating layer and the electrode layer are adjacent to each other on the same plane, and the insulating layer is disposed on the second end side of the first surface of the conductive polymer layer and on the first end side of the second surface of the conductive polymer layer; the metal layer, the conductive polymer layer, the insulating layer, and the electrode layer are laminated together to form a repeating laminate structure as a unit, and the conductive polymer layer, a first insulated electrode layer formed by the insulating layer and the electrode layer and disposed on a first surface of the conductive polymer layer, and a second insulated electrode layer formed by the insulating layer and the electrode layer and disposed on a second surface of the conductive polymer layer, which constitute a repeating unit, are laminated so as to be shifted in an in-plane direction with respect to a repeating unit other than the metal layer; Furthermore, in the laminating step, the conductive polymer layer, a first insulated electrode layer formed by the insulating layer and the electrode layer disposed on a first surface of the conductive polymer layer, a second insulated electrode layer formed by the insulating layer and the electrode layer disposed on a second surface of the conductive polymer layer, and the metal layer, which constitute a repeating unit, are laminated such that the outer peripheries of each layer coincide in an in-plane direction.

6. Furthermore, in the laminating step, the conductive polymer layer, a first insulated electrode layer formed by the insulating layer and the electrode layer arranged on a first surface of the conductive polymer layer, a second insulated electrode layer formed by the insulating layer and the electrode layer arranged on a second surface of the conductive polymer layer, and the metal layer, which constitute a repeating unit, are laminated so that the outer peripheries of each layer coincide in the in-plane direction to form a composite layer; 6. The method for manufacturing a thermoelectric conversion module according to claim 5, wherein the composite layers are stacked such that, in a plane perpendicular to a stacking direction of each layer, a surface of a composite layer other than a predetermined composite layer that corresponds to the predetermined surface forming an outer periphery of the predetermined composite layer is shifted in a diagonal direction in parallel with the predetermined surface.

7. The method for manufacturing a thermoelectric conversion module according to claim 5 or 6, wherein a PEDOT / PSS film is used as the conductive polymer layer.

8. The method for manufacturing a thermoelectric conversion module according to claim 5 , wherein flexible materials are used for the metal layer, the insulating layer, and the conductive polymer layer.

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