Thermoelectric laminate and thermoelectric device

Abstract

Provided are a thermoelectric device that facilitates positioning and joining processes, and a thermoelectric laminate for the same. In a representative embodiment of the present invention, a thermoelectric laminate comprises: a thermoelectric material layer that has a first surface and a second surface facing each other; and an isolation layer that is laminated on the first surface of the thermoelectric material layer. The thermoelectric material layer has a magnetization component perpendicular to the first surface and the second surface. The isolation layer has, if another thermoelectric laminate is laminated on the surface of the isolation layer facing the surface laminated on the thermoelectric material layer, an insulating region that is electrically insulated, and an electrode region that is electrically conductive. Further, in a representative embodiment of the present invention, a thermoelectric device has such thermoelectric laminates being laminated, wherein a plurality of first thermoelectric laminates, in which thermoelectric material layers have positive transverse thermoelectric power, and a plurality of second thermoelectric laminates, in which thermoelectric material layers have negative transverse thermoelectric power, are in close contact with each other in an alternating pattern due to the magnetic force of the magnetization components of the laminates, with respective isolation layers interposed therebetween, and are electrically connected to each other through the electrode regions of the isolation layers.

Description

Thermoelectric laminate and thermoelectric device

[0001] The present invention relates to thermoelectric stacks and thermoelectric devices.

[0002] To improve the efficiency of energy use, the practical application of thermoelectric conversion devices that can generate electricity from waste heat or the environment is desired. As the development of thermoelectric materials with high conversion efficiency progresses, many π-type structures have been proposed in which p-type and n-type thermoelectric materials are alternately connected in series to obtain high electromotive force as a power generation device.

[0003] Patent Document 1 discloses a thermoelectric element in which thermoelectric layers made of a first thermoelectric material and conductive layers made of a second thermoelectric material are alternately stacked with an insulating layer sandwiched therebetween. It is said that a thermoelectric element with improved thermoelectric performance can be realized by making the absolute value of the Seebeck coefficient of the first thermoelectric material constituting the thermoelectric layer greater than the absolute value of the Seebeck coefficient of the second thermoelectric material constituting the conductive layer, making the conductivity of the first thermoelectric material smaller than the conductivity of the second thermoelectric material, and providing an insulating layer between the thermoelectric layer and the conductive layer.

[0004] Patent Document 2 proposes a structure in which a horizontal thermoelectric material with magnetization perpendicular to the surface is electrically connected to a vertical thermoelectric material via an insulating layer. It is said that this will realize a novel thermoelectric conversion element that can increase the thermoelectric power generated in directions perpendicular to both the temperature gradient and magnetization while maintaining the thermoelectric conversion properties of the magnetic material.

[0005] Patent Document 3 proposes a thin film stack structure of a ferromagnetic film / insulator film / thermoelectric material film / insulator film / ferromagnetic film formed on a substrate, which is said to realize a thermoelectric conversion device that is small but can generate a large electromotive force.

[0006] Japanese Patent Application Laid-Open No. 2016-213455 International Publication No. WO2021 / 187347A1 Japanese Patent Application Laid-Open No. 2020-098860

[0007] Conventional π-type thermoelectric modules are formed by stacking block-shaped p-type and n-type thermoelectric materials and electrodes connecting the thermoelectric materials in three dimensions while precisely positioning them, and then bonding them through processes such as pressure and heat application. This requires highly accurate positioning and process control technology.

[0008] An object of the present invention is to provide a thermoelectric device and a thermoelectric stack therefor that are easy to position and bond.

[0009] The means for solving these problems will be described below, but other problems and novel features will become apparent from the description of this specification and the accompanying drawings.

[0010] According to the first embodiment, it is as follows.

[0011] That is, a first embodiment of the present invention is a thermoelectric laminate including a thermoelectric material layer having a first surface and a second surface opposing each other, and an isolation layer laminated on the first surface of the thermoelectric material layer, wherein the thermoelectric material layer has a magnetization component perpendicular to the first surface and the second surface, and the isolation layer has an insulating region that electrically insulates the thermoelectric material layer from a thermoelectric material layer of another thermoelectric laminate when another thermoelectric laminate is laminated on the surface opposite to the surface laminated with the thermoelectric material layer, and an electrode region that electrically connects the thermoelectric material layer to a thermoelectric material layer of the other thermoelectric laminate.

[0012] According to the second embodiment, the following is true.

[0013] That is, a second embodiment of the present invention is the thermoelectric stack described in the first embodiment, wherein the isolation layer extends from an end of the first surface to a side surface of the thermoelectric material layer, and the electrode region is provided in the extended region.

[0014] According to the third embodiment, the following is true.

[0015] That is, a third embodiment of the present invention is the thermoelectric laminate described in the first embodiment, wherein, when another thermoelectric laminate is laminated on the surface opposite to the surface laminated with the thermoelectric material layer, the electrode region of the isolation layer is sandwiched between the thermoelectric material layer and the thermoelectric material layer of the other thermoelectric laminate.

[0016] According to the fourth embodiment, the following is true.

[0017] That is, a fourth embodiment of the present invention is a thermoelectric laminate according to any one of the first to third embodiments, wherein the thermoelectric material layer has a three-dimensional shape on the surface in contact with the isolation layer that fits into the isolation layer.

[0018] According to the fifth embodiment, the following is true.

[0019] That is, a fifth embodiment of the present invention is a thermoelectric laminate described in any of the first to fourth embodiments, wherein when the isolation layer is a first isolation layer, the insulating region is a first insulating region, and the electrode region is a first electrode region, the thermoelectric laminate has a second isolation layer laminated on the second surface, and the second isolation layer has a second insulating region that electrically insulates the thermoelectric material layer from another thermoelectric laminate when the other thermoelectric laminate is laminated on a surface opposite to the surface laminated with the thermoelectric material layer by the magnetic force of the magnetization component, and a second electrode region that electrically connects the thermoelectric material layer to the thermoelectric material layer of the other thermoelectric laminate.

[0020] According to the sixth embodiment, the following is true.

[0021] That is, a sixth embodiment of the present invention is a thermoelectric stack according to the fifth embodiment, wherein the first electrode region and the second electrode region are arranged at positions spaced apart from each other in a plane in which the first surface and the second surface are viewed in plan.

[0022] According to the seventh embodiment, the following is true.

[0023] That is, a seventh embodiment of the present invention is the thermoelectric stack described in the third embodiment, wherein the insulating region has adhesive properties.

[0024] According to the eighth embodiment, the following is true.

[0025] That is, an eighth embodiment of the present invention is the thermoelectric stack described in the seventh embodiment, wherein the insulating region is peelable.

[0026] According to the ninth embodiment, the following is true.

[0027] That is, a ninth embodiment of the present invention is a thermoelectric stack according to any one of the first to eighth embodiments, wherein the thermoelectric material layer is made of two or more thermoelectric materials.

[0028] According to the tenth embodiment, the following is true.

[0029] That is, a tenth embodiment of the present invention is the thermoelectric laminate described in the ninth embodiment, wherein the thermoelectric material layer is formed by stacking unit thermoelectric material layers of the two or more thermoelectric materials.

[0030] According to the eleventh embodiment, the following is true.

[0031] That is, an eleventh embodiment of the present invention is a thermoelectric laminate comprising one or more first thermoelectric laminates as described in any of the first to tenth embodiments, wherein the thermoelectric material layers have positive transverse thermoelectric power, and one or more second thermoelectric laminates as described in any of the first to tenth embodiments, wherein the thermoelectric material layers have negative transverse thermoelectric power, which are alternately brought into close contact with each other, sandwiching their respective isolation layers, by the magnetic forces of their respective magnetization components, and are electrically connected by the electrode regions of the isolation layers.

[0032] According to the twelfth embodiment, the following is true.

[0033] That is, a twelfth embodiment of the present invention is the thermoelectric device described in the eleventh embodiment, wherein the thermoelectric material of the first thermoelectric stack is a magnetic material containing at least one material selected from the group consisting of a samarium-cobalt (Sm—Co) alloy, a cobalt-manganese-gallium (CoMnGa) alloy, a cobalt-manganese-aluminum / silicon (CoMn(Al,Si)) alloy, cobalt (Co), an iron-gallium (Fe—Ga) alloy, an iron-aluminum (Fe—Al) alloy, an iron-platinum (FePt) alloy, an iron-lead (FePd) alloy, an iron-tin (FeSn) alloy, and iron nitride (FeN); and the thermoelectric material of the second thermoelectric stack is a magnetic material containing at least one material selected from the group consisting of a neodymium-iron-boron (NdFeB) alloy, a manganese-gallium (MnGa) alloy, iron (Fe), and a cobalt-gadolinium (Co—Gd) alloy.

[0034] According to the thirteenth embodiment, the following is true.

[0035] That is, a thirteenth embodiment of the present invention is a thermoelectric device in which one or more first thermoelectric material layers having positive transverse thermoelectric power and one or more second thermoelectric material layers having negative transverse thermoelectric power are alternately stacked with an isolation layer sandwiched therebetween, wherein the first and second thermoelectric material layers have magnetization components in the same direction perpendicular to the stacking plane, the isolation layer has electrode regions that connect insulating regions that electrically insulate the adjacent first and second thermoelectric material layers by being tightly attached by the magnetic force of the magnetization components, and the electrode regions that contact both surfaces of the first and second thermoelectric material layers are arranged at positions in each thermoelectric material layer that are spaced apart in directions perpendicular to both the stacking direction and the direction in which a temperature gradient is applied.

[0036] According to the fourteenth embodiment, the following is true.

[0037] That is, a fourteenth embodiment of the present invention is a thermoelectric device described in the thirteenth embodiment, wherein the isolation layer extends from the end of the stacking surface to the side surface of the thermoelectric material layer, and has the electrode region in the extended region.

[0038] According to the fifteenth embodiment, the following is true.

[0039] That is, a fifteenth embodiment of the present invention is a thermoelectric device described in the thirteenth embodiment, in which the first and second thermoelectric material layers adjacent to each other are stacked with the isolation layer sandwiched therebetween by the magnetic force of the magnetization component so as to be detachable.

[0040] According to the sixteenth embodiment, the following is true.

[0041] That is, a sixteenth embodiment of the present invention is a thermoelectric device according to any one of the thirteenth to fifteenth embodiments, wherein the first and second thermoelectric material layers have a three-dimensional shape that fits into the isolation layer on at least one surface that is in close contact with the electrode region of the isolation layer.

[0042] According to the seventeenth embodiment, the following is true.

[0043] That is, a seventeenth embodiment of the present invention is the thermoelectric device according to any one of the thirteenth to sixteenth embodiments, wherein the first thermoelectric material is a magnetic material containing at least one material selected from the group consisting of an Sm—Co alloy, a CoMnGa alloy, a CoMn(Al,Si) alloy, Co, an Fe—Ga alloy, an Fe—Al alloy, an FePt alloy, an FePd alloy, an FeSn alloy, and iron nitride (FeN), as a main component, and the second thermoelectric material is a magnetic material containing at least one material selected from the group consisting of an NdFeB alloy, an MnGa alloy, Fe, and a Co—Gd alloy as a main component.

[0044] According to the eighteenth embodiment, the following is true.

[0045] That is, an 18th embodiment of the present invention is a thermoelectric device according to any one of the 13th to 16th embodiments, wherein at least one of the first and second thermoelectric material layers is a laminate made up of multiple layers of mutually different thermoelectric materials.

[0046] The effects obtained by the embodiment are briefly described below.

[0047] That is, it is possible to provide a thermoelectric device and a thermoelectric laminate therefor that are easy to position and bond.

[0048] FIG. 1 is an explanatory diagram schematically showing the basic structure of a thermoelectric laminate of the present invention. FIG. 2 is an explanatory diagram schematically showing the operating principle of a thermoelectric device of the present invention. FIG. 3 is an explanatory diagram showing an example of the configuration of a thermoelectric device according to an embodiment of the present invention. FIG. 4 is an explanatory diagram showing a modified electrode region. FIG. 5 is an explanatory diagram showing another modified electrode region. FIG. 6 is an explanatory diagram showing another electrode structure. FIG. 7 is a graph showing measurement results confirming the power generation behavior of a thermoelectric material fabricated as an embodiment. FIG. 8 is a graph showing the power generation performance of a horizontal thermoelectric module fabricated as an embodiment. FIG. 9 is an explanatory diagram showing another example of the configuration of a thermoelectric device according to the present invention.

[0049] 1. Overview of the Embodiments First, an overview of the representative embodiments disclosed in the present application will be described. Reference numerals in parentheses in the drawings used in the overview of the representative embodiments merely illustrate components included in the concept of the components to which they are attached.

[0050] [1] Thermoelectric laminate having a magnetization component perpendicular to the contact surface and electrically connected by a part of an isolation layer (FIGS. 1 to 6) A representative embodiment disclosed in the present application is a thermoelectric laminate (10) having a thermoelectric material layer (1) having a first surface and a second surface facing each other, and an isolation layer (2) laminated on the first surface of the thermoelectric material layer, wherein the thermoelectric material layer has a magnetization component (5) perpendicular to the first surface and the second surface, and the isolation layer has an insulating region (3) that electrically insulates the thermoelectric material layer from a thermoelectric material layer of another thermoelectric laminate when another thermoelectric laminate is laminated on the surface opposite to the surface laminated with the thermoelectric material layer, and an electrode region (4) that electrically connects the thermoelectric material layer to a thermoelectric material layer of the other thermoelectric laminate.

[0051] This makes it possible to provide a thermoelectric stack that facilitates the positioning and bonding process for constructing a thermoelectric device.

[0052] [2] Electrode regions extend to the side surfaces of the thermoelectric material layers (FIGS. 4 and 5). In the thermoelectric laminate described in [1], the isolation layer extends from the end of the first surface to the side surfaces of the thermoelectric material layers, and the electrode regions are provided in the extended regions.

[0053] This allows for greater flexibility in the electrode formation and wiring processes. Furthermore, by forming the electrode regions (4) at the ends of the thermoelectric material layer (1) (e.g., FIG. 5), the entire thermoelectric material layer can be configured to contribute to thermoelectric conversion.

[0054] [3] The electrode region is a region sandwiched between thermoelectric material layers (FIGS. 1 and 4). In the thermoelectric laminate described in [1], when another thermoelectric laminate is laminated on the surface opposite to the surface laminated with the thermoelectric material layer, the electrode region of the isolation layer is sandwiched between the thermoelectric material layer and the thermoelectric material layer of the other thermoelectric laminate.

[0055] This allows the magnetic stress to be applied directly to the interface between the electrode region and the thermoelectric material layer, resulting in good contact electrical conductivity. It also maximizes the area of ​​the thermoelectric material layer relative to the area through which heat flow passes. The contribution of the thermoelectric material layer to thermoelectric conversion also depends on the position and area of ​​the electrode region.

[0056] [4] Three-dimensional structure in which thermoelectric material layer is interlocked with electrode (FIG. 6) The thermoelectric laminate according to any one of [1] to [3], wherein the thermoelectric material layer has a three-dimensional shape that interlocks with the isolation layer on the surface that contacts the isolation layer.

[0057] This allows the thermoelectric material layer and the electrodes to be positioned in a self-aligned manner, further facilitating the wiring process.

[0058] [5] Electrical connection by magnetic force of magnetization component (FIG. 2) A thermoelectric laminate (12) according to any one of [1] to [4], wherein the isolation layer is a first isolation layer (2-2), the insulating region is a first insulating region (3-2), and the electrode region is a first electrode region (4-3), the thermoelectric laminate has a second isolation layer (2-1) laminated on the second surface, and the second isolation layer has a second insulating region (3-1) that electrically insulates the thermoelectric material layer from a thermoelectric material layer of another thermoelectric laminate when another thermoelectric laminate is laminated on a surface opposite to the surface laminated with the thermoelectric material layer by the magnetic force of the magnetization component, and a second electrode region (4-2) that electrically connects the thermoelectric material layer to a thermoelectric material layer of the other thermoelectric laminate.

[0059] As a result, electrical connection is formed by close contact due to the magnetic force of the magnetization component of the thermoelectric material layer, and no further wiring process is required.

[0060] [6] Acquisition of electromotive force by horizontal thermoelectric conversion The thermoelectric stack according to [5], wherein the first electrode region and the second electrode region are arranged at positions spaced apart from each other in a plane in which the first surface and the second surface are viewed in plan.

[0061] As a result, by arranging two electrodes at separate positions within the plane of one thermoelectric material layer and applying a temperature gradient perpendicular to the direction of separation and perpendicular to the stacking direction, electromotive force generated in the thermoelectric material layer due to horizontal thermoelectric conversion can be extracted from between the two electrodes. The first electrode region (4-3) and the second electrode region (4-2) are preferably located on both sides of the thermoelectric material layer (1-2) in the stacking direction of the thermoelectric stack (12), and are preferably located at positions where the potential difference (electromotive force) generated by the driving electric field generated in the direction of the cross product of the applied temperature gradient and the residual magnetization component is maximized. Here, the first electrode region (4-3) and the second electrode region (4-2) may be composed of multiple electrode regions located at approximately the same potential. However, the symbols in parentheses are examples used with reference to FIG. 2 and are not limited to this.

[0062] [7] Adhesiveness In the thermoelectric stack according to [3], the insulating region has adhesiveness.

[0063] This makes it possible to further strengthen the adhesion due to the magnetic force of the residual magnetization.

[0064] [8] Ease of Peeling In the thermoelectric stack according to [7], the insulating region is peelable.

[0065] This makes it easy to disassemble the thermoelectric conversion element formed from this thermoelectric laminate.

[0066] [9] Thermoelectric Laminate Composed of Two or More Thermoelectric Materials The thermoelectric laminate according to any one of claims 1 to 8, wherein the thermoelectric material layer is composed of two or more thermoelectric materials.

[0067] This increases the degree of freedom in the selection of thermoelectric materials.

[0068]

[10] Gradient Laminate (FIG. 9) The thermoelectric laminate according to [9], wherein the thermoelectric material layer is formed by laminating unit thermoelectric material layers of the two or more thermoelectric materials.

[0069] This makes it possible to adopt a lateral thermoelectric material in which p-type and n-type thermoelectric materials are alternately layered with a gradient as the thermoelectric material layer. The above-mentioned "gradient laminate" is a multilayer structure in which two or more types of thermoelectric material layers (the above-mentioned "unit thermoelectric material layers") are layered, and the "lamination" referred to here is different from the "lamination" referred to in [1].

[0070]

[11] Thermoelectric device A representative embodiment disclosed in the present application is a thermoelectric device, in which one or more first thermoelectric laminates as described in any one of [1] to

[10] , in which the thermoelectric material layers have positive lateral thermoelectric power, and one or more second thermoelectric laminates as described in any one of [1] to

[10] , in which the thermoelectric material layers have negative lateral thermoelectric power, are alternately brought into close contact with each other by the magnetic forces of their magnetization components, sandwiching their respective isolation layers, and are electrically connected by the electrode regions of the isolation layers.

[0071] This makes it possible to provide a thermoelectric device that is easy to position and bond.

[0072]

[12] Specific Thermoelectric Materials The thermoelectric device according to

[11] , wherein the thermoelectric material of the first thermoelectric laminate is a magnetic material containing at least one material selected from the group consisting of Sm-Co alloy, Co2MnGa alloy, Co2Mn(Al,Si) alloy, Co, Fe-Ga alloy, Fe-Al alloy, FePt alloy, FePd alloy, Fe3Sn2 alloy, and iron nitride (Fe4N), and the thermoelectric material of the second thermoelectric laminate is a magnetic material containing at least one material selected from the group consisting of NdFeB alloy, MnGa alloy, Fe, and Co-Gd alloy.

[0073] This allows the identification of suitable thermoelectric materials for constructing the thermoelectric device described in

[11] .

[0074]

[13] Lateral Thermoelectric Device Connected in Series by Magnetic Force of Magnetization Components (FIGS. 2 and 3) A representative embodiment disclosed in the present application is a thermoelectric device in which one or more first thermoelectric material layers (1-2) having positive lateral thermoelectric power and one or more second thermoelectric material layers (1-1) having negative lateral thermoelectric power are alternately stacked with isolation layers (2-1, 2-2) sandwiched therebetween, and is configured as follows:

[0075] The first and second thermoelectric material layers have magnetization components (5-1, 5-2) in the same direction perpendicular to the lamination plane. The isolation layer has insulating regions (3-1, 3-2) that electrically insulate the adjacent first and second thermoelectric material layers by the magnetic force of the magnetization components, and electrode regions (4-2, 4-3) that conduct the insulating regions. The electrode regions (4-1 and 4-2, 4-2 and 4-3) that contact both surfaces of the first and second thermoelectric material layers are arranged in positions on each thermoelectric material layer that are spaced apart in a direction perpendicular to both the lamination direction and the direction in which a temperature gradient is applied.

[0076] This allows for a thermoelectric device that is easy to position and bond. The positions spaced apart in a direction perpendicular to both the stacking direction and the direction in which the temperature gradient is applied are positions where the potential difference (electromotive force) caused by the driving electric field generated by the temperature gradient and residual magnetization is maximized. Here, each electrode region may be composed of multiple electrode regions arranged at positions with approximately the same potential.

[0077]

[14] Electrode regions extend to the side surfaces of the thermoelectric material layers (FIGS. 4 and 5). In the thermoelectric device described in

[13] , the isolation layer extends from the end of the laminated surface to the side surfaces of the thermoelectric material layers, and the electrode regions are located in the extended regions.

[0078] This allows stress due to magnetic force to be applied directly to the interface between the electrode region and the thermoelectric material layer, resulting in good contact electrical conductivity. It also increases the degree of freedom in electrode formation and wiring processes. Furthermore, by forming the electrode region (4) at the end of the thermoelectric material layer (1) (e.g., FIG. 5), the entire thermoelectric material layer can be configured to contribute to thermoelectric conversion.

[0079]

[15] Easy attachment and detachment by magnetic adhesion In the thermoelectric device described in any one of

[13] to

[15] , the first and second thermoelectric material layers adjacent to each other are stacked with the isolation layer sandwiched between them so as to be detachable by the magnetic force of the magnetization component.

[0080] This facilitates the positioning and bonding process, and allows for flexible response, such as adjusting the number of thermoelectric stacks to be stacked in accordance with the size of the object to be installed at the installation site.

[0081]

[16] Three-dimensional structure in which thermoelectric material layers are interlocked with electrodes (FIG. 4) In the thermoelectric device described in any one of

[13] to

[15] , the first and second thermoelectric material layers have a three-dimensional shape that interlocks with the isolation layer on at least one surface that is in close contact with the electrode region of the isolation layer.

[0082] This allows the thermoelectric material layer and the electrodes to be positioned in a self-aligned manner, further facilitating the wiring process.

[0083]

[17] Specific Thermoelectric Material The thermoelectric device according to any one of

[13] to

[16] , wherein the first thermoelectric material is a magnetic material containing at least one material selected from the group consisting of an Sm-Co alloy, a Co2MnGa alloy, a Co2Mn(Al,Si) alloy, Co, an Fe-Ga alloy, an Fe-Al alloy, an FePt alloy, an FePd alloy, an Fe3Sn2 alloy, and iron nitride (Fe4N) as a main component, and the second thermoelectric material is a magnetic material containing at least one material selected from the group consisting of an NdFeB alloy, an MnGa alloy, Fe, and a Co-Gd alloy as a main component.

[0084] This allows the identification of suitable thermoelectric materials for constructing the thermoelectric devices described in

[13] to

[16] .

[0085]

[18] Gradient laminate The thermoelectric device according to any one of

[13] to

[16] , wherein at least one of the first and second thermoelectric material layers is a laminate made of multiple layers of thermoelectric materials different from each other.

[0086] This makes it possible to adopt a lateral thermoelectric material in which p-type and n-type thermoelectric materials are alternately layered with a gradient as the thermoelectric material layer. The above-mentioned "gradient laminate" is a multilayer structure in which two or more types of thermoelectric material layers (the above-mentioned "unit thermoelectric material layers") are layered, and the "lamination" referred to here is different from the "lamination" referred to in

[13] .

[0087] 2. Details of the embodiment The embodiment will be described in further detail.

[0088] [Embodiment 1] Figure 1 is an explanatory diagram schematically illustrating the basic configuration of a thermoelectric laminate 10 of the present invention. The thermoelectric laminate 10 has a thermoelectric material layer 1 and an isolation layer 2. The isolation layer 2 is laminated on one of two opposing surfaces of the thermoelectric material layer 1 (on the +x side of the y-z plane in Figure 1). The thermoelectric material layer 1 has a magnetization component 5 perpendicular to the two surfaces (in the x-axis direction). The isolation layer 2 has, within the surface that contacts the thermoelectric material layer 1 when laminated, an insulating region 3 that provides insulation between two adjacent thermoelectric material layers 1 and an electrode region 4 that provides electrical conduction between them.

[0089] This makes it possible to provide a thermoelectric laminate 10 that facilitates the positioning and bonding process for constructing a thermoelectric device. The two thermoelectric material layers 1 are tightly attached with the isolation layer 2 sandwiched therebetween by the magnetic force of the magnetization component perpendicular to the lamination surface, and are electrically connected at the electrode regions 4 that are part of the isolation layer 2. This makes alignment easy, does not require a bonding process, and after bonding, wiring only needs to be done at both ends. Therefore, for example, when installing a thermoelectric device, the number of thermoelectric laminates 10 to be stacked can be adjusted to suit the size of the target object, even at the installation site.

[0090] FIG. 2 is an explanatory diagram schematically illustrating the operating principle of the thermoelectric device of the present invention. As described above, the thermoelectric laminate 1 of the present invention has a magnetization component perpendicular to the lamination surface, and therefore can be bonded by magnetic force if aligned in the same direction. FIG. 2 shows a thermoelectric laminate 12 having an insulating region 3-2 and an electrode region 4-3 in an isolation layer 2-2 on one surface, on the other surface of which another thermoelectric laminate 11 is laminated. The thermoelectric laminates 11 and 12 have magnetization components 5-1 and 5-2 in the same direction perpendicular to the lamination surface, and are bonded by magnetic force in the left-right direction of the page. From the perspective of the thermoelectric laminate 12, the surface on which the other thermoelectric laminate 11 is laminated has an isolation layer 2-1. When the thermoelectric laminate 11 is magnetically bonded to the insulating region 3-1, the insulating region 3-1 is electrically insulated, and the electrode region 4-2 is electrically conductive.

[0091] 2, when the thermoelectric laminates 11 and 12 are constructed using thermoelectric materials with positive and negative horizontal thermoelectric power, respectively, the electromotive forces of the thermoelectric laminates 11 and 12 are integrated by electrically connecting them in series, making it possible to output a high voltage. If the direction of the temperature gradient 30 is perpendicular to the paper surface and runs from the front to the back as shown in FIG. 2, in the thermoelectric laminate 11 with positive horizontal thermoelectric power, the driving electric field E ANE As a result, the ratio of the potential gradient and the temperature gradient that occur from the bottom to the top of the paper in the open-circuit voltage state is the anomalous Nernst coefficient S ANE The thermoelectric stack 12 has a negative anomalous Nernst coefficient S ANE In the thermoelectric stack 12, the driving electric field E is expressed as the cross product component of the temperature gradient 30 and the magnetic force of the magnetization component 5-2. ANE 20-2 occurs downward from the top of the paper.

[0092] The electrode regions 4-1 and 4-2 in contact with both surfaces of the thermoelectric material layer 1-1, and the electrode regions 4-2 and 4-3 in contact with both surfaces of the thermoelectric material layer 1-2, are arranged at positions separated from each other in a direction perpendicular to both the stacking direction and the direction in which the temperature gradient 30 is applied in each thermoelectric material layer. It is most preferable to arrange them at the ends furthest apart. A driving electric field E ANE The potential difference between the two ends of the electrode region 4-2 is maximized, and the maximum value of the generated electromotive force can be extracted. The electrode regions 4-2 and 4-3 are located at approximately the same potential, and may be divided into multiple electrode regions.

[0093] As described above, the thermoelectric stacks 11 and 12 are insulated in the insulating region 3-2 and are conductive in the electrode region 4-2, and are therefore connected in series between the electrode 4-3 and the electrode 4-1, and the driving electric field E ANE Potential difference and driving electric field E due to 20-2 ANE The sum of the potential differences due to 20-1 is output. In this way, the anomalous Nernst coefficient S ANE By alternately bringing materials having the above properties into close contact with each other using magnetic force while ensuring electrical insulation, and then electrically connecting them in series, it is possible to obtain a high-density horizontal thermoelectric module.

[0094] The thermoelectric element of the present invention is also highly efficient in terms of volume utilization. In conventional π-type thermoelectric devices, p-type and n-type thermoelectric materials are each formed into a columnar shape and arranged at a distance from each other. Because the columnar thermoelectric materials are spaced apart by alignment, the gaps become volume that does not directly contribute to thermoelectric conversion.

[0095] On the other hand, in the thermoelectric element of the present invention, when viewed from the vector direction of the temperature gradient 30, the area through which the heat flow passes is composed only of the thermoelectric material layer 1 and the isolation layer 2. The isolation layer 2 only needs to be insulated when magnetically attached, and because the potential difference is low, it does not need to be thick enough to ensure dielectric strength; a thin film-like thickness is sufficient. Therefore, the thermoelectric material layer 1 occupies most of the area through which the heat flow passes, allowing most of the heat flow to directly contribute to thermoelectric conversion. Furthermore, even in the direction from the front to the back of the vector of the temperature gradient 30, a structure can be formed in which only the thermoelectric material layer 1 occupies the area, without the need for electrodes or substrates. Thus, the presence of substances other than the thermoelectric material is extremely small both on the surface through which the heat flow passes and in the path along which the heat flow passes. Therefore, the thermoelectric element of the present invention can be said to be highly efficient in terms of volume utilization.

[0096] Second Embodiment FIG. 2 shows a simple thermoelectric device in which one thermoelectric laminate 11 and one thermoelectric laminate 12 are stacked, but the number of laminated layers is arbitrary.

[0097] FIG. 3 is an explanatory diagram showing an example of the configuration of a thermoelectric device 100 according to one embodiment of the present invention. The thermoelectric device 100 is configured by alternately stacking five thermoelectric laminates 11 and five thermoelectric laminates 12. In the thermoelectric device 100, thermoelectric material layers with positive transverse thermoelectric power included in the thermoelectric laminate 11 and thermoelectric material layers with negative transverse thermoelectric power included in the thermoelectric laminate 12 are alternately stacked with an isolation layer sandwiched between them. The thermoelectric material layers of the thermoelectric laminates 11 and 12 have magnetization components in the same direction perpendicular to the stacking surface (x-axis direction). The isolation layer tightly contacts the adjacent thermoelectric material layers with the magnetic force of the magnetization components, insulating them in the insulating regions and electrically conducting them in the electrode regions. This magnetization component not only tightly contacts the thermoelectric laminate but also generates a driving electric field E in the thermoelectric material layers due to the anomalous Nernst effect. ANE That is, when a temperature gradient is applied in the y-axis direction, a driving electric field E is generated in each thermoelectric material layer due to the anomalous Nernst effect. ANEare generated in opposite directions between adjacent thermoelectric material layers. The electrode regions that electrically connect adjacent thermoelectric material layers are alternately arranged at the furthest positions in the direction (z-axis direction) perpendicular to both the temperature gradient and the stacking direction, so the potential differences generated alternately in opposite directions are connected in series, and the large potential difference integrated across both ends can be output as electromotive force.

[0098] Since the thermoelectric stacks 11 and 12 have magnetization components in the same direction in the stacking direction, they are closely attached and electrically connected by magnetic force simply by arranging them adjacent to each other, so the positioning and joining processes in the thermoelectric device 100 are extremely easy.

[0099] [Embodiment 3] In embodiments 1 and 2, as exemplified mainly in Figures 1 to 3, thermoelectric material layers 1 (1-1, 1-2) and isolation layers 2 (2-1, 2-2) overlap with the same area when viewed from the x-axis direction. In such a configuration, as described above, no components are inserted in series in the path through which heat flows in the thermoelectric material layers, and only thermoelectric material layers 1 and isolation layers 2 are present in parallel. Therefore, the applied temperature gradient is applied to thermoelectric material layer 1 with almost no waste, and is expected to contribute to thermoelectric conversion. On the other hand, the structure of electrode regions 4 is not limited to this, and part or all of electrode regions 4 may extend to the side walls of thermoelectric material layer 1 and may even be formed apart from insulating regions 3 of isolation layers 2.

[0100] 4 and 5 are explanatory diagrams of modified electrode regions. As shown in FIG. 4, a portion of the electrode region 4 may extend to the side (z-side or -z-side) of the thermoelectric material layer 1. Extending to the side allows the entire thermoelectric material to contribute to thermoelectric conversion, thereby enabling an ideal thermoelectric voltage to be obtained. For example, as shown in FIG. 5, by forming the electrode region 4 at the end of the thermoelectric material layer 1, all electromotive forces generated anywhere from one end of the thermoelectric material layer 1 to the other can be extracted by flowing them through the electrode region 4. Electrical connection with the thermoelectric material layer 1 of an adjacent thermoelectric stack 10 may be formed at the contact surface as in FIG. 1, or additional wiring, such as indium crimp wiring, may be added. Alternatively, the entire electrode region 4 may be formed on the side of the thermoelectric material layer 1, as shown in FIG. 5. In this case, after the thermoelectric laminate 10 consisting of the isolation layer 2 having only the insulating region 3 and the thermoelectric material layer 1 is laminated in close contact with each other due to their mutual residual magnetization, crimped wiring made of, for example, indium is formed to electrically connect adjacent thermoelectric material layers 1 so that a series circuit is formed overall.

[0101] [Embodiment 4] Figure 6 is an explanatory diagram of another electrode structure. In the thermoelectric laminate of this embodiment, the thermoelectric material layer 1 has a three-dimensional shape on the surface in contact with the isolation layer 2 that fits into the isolation layer 2. This allows the thermoelectric material layer and the electrode to be positioned in a self-aligned manner, further facilitating the wiring process. Figure 6 shows an example. The thermoelectric material layer 1 on the left side has notches 41 and 42. The isolation layer 2, which is laminated from the right side of the figure, has an electrode region 4 that is thicker than the insulating region 3. When the thermoelectric material layer 1 and the isolation layer 2 are bonded together, the electrode region 4 of the isolation layer fits into the notches 41 and 42 of the thermoelectric material layer 1. The size of the electrode region 4, which protrudes toward the thermoelectric material layer 1 beyond the insulating region 3, is preferably designed so that it fits snugly into the notches 41 and 42. This facilitates alignment of the thermoelectric material layer and the isolation layer. Furthermore, the increased contact area between the thermoelectric material layer and the electrode region 4 also reduces contact resistance. In this example, a simple notch is used, but by adopting a shape that increases the contact area, it is possible to further reduce the electrical contact resistance.

[0102] 6, the electrode region 4 may be configured to protrude on both sides beyond the leading edge region 3, and may be configured to fit with another thermoelectric material layer 1 that is brought into close contact with the opposite side (further to the right in FIG. 6). Furthermore, the thermoelectric material layer 1 may be provided with notches 43 and 44, and 45 and 46, respectively, on both sides to be laminated, as exemplified in the right end of FIG.

[0103] [Embodiment 5] The thermoelectric material layer 1 can be a layer that utilizes various transverse thermoelectric conversion phenomena. For example, transverse thermoelectric materials such as magnetic materials that exhibit the anomalous Nernst effect or the spin Seebeck effect, and goniopolar materials with anisotropic Seebeck coefficients can be used. Furthermore, a geometrically induced transverse thermoelectric material can be used, configured by alternately stacking p-type and n-type Seebeck materials obliquely with respect to the temperature gradient direction. Such a composite material can combine various transverse thermoelectric conversion phenomena to enhance output.

[0104] FIG. 9 is an explanatory diagram showing another example of the configuration of a thermoelectric device of the present invention. Similar to the second embodiment, the thermoelectric laminates 11 and 12 are respectively composed of a thermoelectric material layer 1-1 and an isolation layer 2-1, and a thermoelectric material layer 1-2 and an isolation layer 2-2, which are in close contact with each other to form the thermoelectric device. The thermoelectric material layers 1-1 and 1-2 are each composed of two types of thermoelectric material layers 1a and 1b, and 1c and 1d, alternately stacked, with the stacking direction tilted from the temperature gradient 30. For example, by using p-type and n-type thermoelectric materials for the thermoelectric material layers 1a and 1b, and 1c and 1d, respectively, the layers can function as horizontal thermoelectric material layers, and the sign of the driving electric field can be reversed by reversing the tilt angle with respect to the temperature gradient (y-axis direction). Furthermore, the thermoelectric material layers 1a or 1b, 1c or 1d can be made of magnetic materials to generate magnetization components 5-1 and 5-2.

[0105] As an example of a thermoelectric device in which laminates can be connected by magnetic force, a horizontal thermoelectric module was fabricated using two types of permanent magnets with different signs of the anomalous Nernst effect, which is one type of horizontal thermoelectric power, and its characteristics were evaluated. The operating principle of the horizontal thermoelectric module of this example is as described in embodiment 2.

[0106] [Module processing] Anomalous Nernst coefficient S with reversed sign ANE The materials used were a samarium cobalt (SmCo5) magnet with a diameter of 20 mm and a thickness of 0.5 mm (Magfine Corporation YX24) and a neodymium iron boron (Nd2Fe 14 B) Magnet: 20 mm diameter x 0.5 mm thickness (Magfine Corporation N35, NiCuNi plated). SmCo5 magnet has a positive anomalous Nernst coefficient S ANE , NdFe 14 B magnets have a negative anomalous Nernst coefficient S ANE Each of them has:

[0107] Disk-shaped SmCo5 magnet and Nd2Fe 14 A magnet with a B magnet and a B magnet were alternately stacked in groups of 12 in the same direction of magnetization to create a total of 24 stacks. When stacking, a paper towel (manufactured by AS ONE) was placed on the bottom magnet as an insulating layer, and instant adhesive (Aron Alpha Tough Power, manufactured by Toagosei Co., Ltd.) was applied, and then the next magnet (with an anomalous Nernst coefficient S ANE The disks were fixed together by placing a magnet (having a .DELTA.) on top.

[0108] The resulting laminate was cut into a rectangular parallelepiped shape using a diamond wire saw (DWS100 manufactured by Sakae Research Co., Ltd.). 14 The sides of the material were crimped with indium (manufactured by Nilaco Corporation) to form a circuit in which the A magnets were alternately connected in series, completing a horizontal thermoelectric module.

[0109] Two copper wires (manufactured by Nilaco Corporation) were connected to both ends of the electrical circuit of the completed horizontal thermoelectric module, and the sides excluding the contact surface and the opposing contact surface were fixed with a heat-dissipating adhesive (COM-G52 manufactured by Com Lab LLC).

[0110] The thermoelectric material, SmCo5 magnet and Nd2Fe, is placed on the heat receiving surface of the module. 14 The area ratio occupied by the B magnets exceeds 81%, which is an occupation density unparalleled compared to conventional π-type thermoelectric modules.

[0111] In the horizontal thermoelectric module of this embodiment, the separator having the insulating region and the electrode region can be formed by, for example, the following film forming process, coating process, and pasting process.

[0112] Film formation process: A film of metal such as aluminum (Al) is formed on a magnet, which is a thermoelectric material. The electrode area is covered with an anti-oxidation film such as resist, and the other parts are oxidized to form an insulating area. The anti-oxidation film is then removed using an organic solvent, etc.

[0113] Application process: Silver paste or indium is applied to the electrode area, and high-heat resistant adhesive or Aron ceramic is applied to the insulating area.

[0114] Attachment process: Adhesive tape with a conductive area is attached. The adhesive tape with a conductive area is, for example, an adhesive tape with a conductive circuit section that penetrates the surface and an insulating section other than that, and becomes electrically conductive when attached to a magnet.

[0115] [Measurement of power generation performance] The power generation performance of the fabricated horizontal thermoelectric module was evaluated by four-terminal measurement of the current-voltage characteristics of the two copper wires with a temperature difference ΔT applied to both sides of the module. That is, one of the copper wires was defined as a positive voltage (V+) and a negative current (I-), and the other was defined as a negative voltage (V-) and a positive current (I+). load The voltage V was measured by sweeping the load current I load and the voltage V.

[0116] 7 is a graph showing the measurement results for confirming the power generation behavior of the thermoelectric material fabricated as an example. Specifically, the open circuit voltage V was measured using the following procedure to confirm that the output generated by the temperature difference ΔT is due to the anomalous Nernst effect.

[0117] A pulsed magnetic field generator (manufactured by Toei Scientific Industry Co., Ltd.) was used to generate SmCo5 magnets and Nd2Fe 14A voltage of +8 T was applied to the easy axis of magnet B to magnetize it, and in this state a temperature difference ΔT was applied to measure the open circuit voltage V (Circle number 1). Next, the same procedure was repeated three times at -8 T, +8 T, and -8 T for the SmCo5 magnet and the Nd2Fe 14 The magnetization of the B magnet was reversed in turn, and the open circuit voltage was measured each time (Circle numbers 2 to 4). The inset shows the sign reversal of the anomalous Nernst voltage due to magnetization reversal, converted into V / ΔT. In Figure 7, the horizontal axis shows the applied temperature difference ΔT (K), and the vertical axis shows the electromotive force V (mV) of the horizontal thermoelectric module. Figure 7 also shows the electromotive force V (mV) of the SmCo5 magnet and Nd2Fe 14 B Anomalous Nernst coefficient S of each magnet ANE The anomalous Nernst voltage calculated from the temperature difference, dimensions, and number of layers is shown by the dashed line as the calculated value (Calc.). The measurement results in Figure 7 show that the open-circuit voltage behaves symmetrically depending on the magnetization direction and is in good agreement with the calculated value of the anomalous Nernst voltage, confirming that the open-circuit voltage V obtained in the experiment is due to the anomalous Nernst effect.

[0118] Figure 8 is a graph showing the power generation performance of the horizontal thermoelectric module fabricated as an example. Four temperature differences ΔT = 21K, 39K, 60K, and 75K were used as parameters, and the load current I was swept while applying each temperature difference ΔT. load The horizontal axis is the measured voltage V (mV), the vertical axis is the measured voltage V (mV), and the load current I load The generated power P (μW), which is the product of the current (mA) and the temperature difference (ΔT), is shown on the right vertical axis. Measurements showed that a maximum generated power of 177 μW was measured at a temperature difference ΔT of 75 K. This generated power is equivalent to 65 μW / cm2 per unit contact area. 2 This results in a power generation density of

[0119] The invention made by the inventor has been specifically described above based on an embodiment, but it goes without saying that the invention is not limited thereto and can be modified in various ways without departing from the spirit of the invention.

[0120] 1, 1-1, 1-2 Thermoelectric material 2, 2-1, 2-2 Separation layer 3, 3-1, 3-2 Insulation region 4, 4-1, 4-2, 4-3 Electrode region 5, 5-1, 5-2 Magnetization component perpendicular to the lamination surface 10, 11, 12 Thermoelectric laminate 20-1, 20-2 Driving electric field 30 Temperature gradient 41 to 46 Notch in thermoelectric material layer 100 Thermoelectric device

Claims

1. A thermoelectric stack having a thermoelectric material layer having a first surface and a second surface opposed to each other, and an isolation layer laminated on the first surface of the thermoelectric material layer, wherein the thermoelectric material layer has a magnetization component perpendicular to the first and second surfaces, and the isolation layer has an insulating region that electrically insulates the thermoelectric material layer from a thermoelectric material layer of another thermoelectric stack when another thermoelectric stack is laminated on a surface opposite to the surface laminated with the thermoelectric material layer, and an electrode region that electrically connects the thermoelectric material layer to the thermoelectric material layer of the other thermoelectric stack.

2. A thermoelectric stack as described in claim 1, wherein the isolation layer extends from an end of the first surface to a side surface of the thermoelectric material layer, and the electrode region is provided in the extended region.

3. A thermoelectric stack as claimed in claim 1, wherein, when another thermoelectric stack is stacked on the surface opposite to the surface stacked with the thermoelectric material layer, the electrode region of the isolation layer is sandwiched between the thermoelectric material layer and the thermoelectric material layer of the other thermoelectric stack.

4. A thermoelectric stack according to any one of claims 1 to 3, wherein the thermoelectric material layer has a three-dimensional shape on the surface in contact with the isolation layer that fits into the isolation layer.

5. A thermoelectric laminate as described in any one of claims 1 to 4, comprising the isolation layer as a first isolation layer, the insulating region as a first insulating region, and the electrode region as a first electrode region, and a second isolation layer laminated on the second surface, the second isolation layer having a second insulating region that electrically insulates the thermoelectric material layer from the thermoelectric material layer of the other thermoelectric laminate when another thermoelectric laminate is laminated on the surface opposite to the surface laminated with the thermoelectric material layer by the magnetic force of the magnetization component, and a second electrode region that electrically connects the thermoelectric material layer to the thermoelectric material layer of the other thermoelectric laminate.

6. A thermoelectric laminate according to claim 5, wherein the first electrode region and the second electrode region are arranged at positions spaced apart from each other in a plane in which the first surface and the second surface are viewed in plan.

7. A thermoelectric stack according to claim 3, wherein said insulating region has adhesive properties.

8. A thermoelectric stack as claimed in claim 7, wherein said insulating region is peelable.

9. A thermoelectric stack according to any one of claims 1 to 8, wherein the thermoelectric material layer is made of two or more thermoelectric materials.

10. A thermoelectric laminate according to claim 9, wherein the thermoelectric material layer is formed by stacking unit thermoelectric material layers of the two or more thermoelectric materials.

11. A thermoelectric device comprising one or more first thermoelectric laminates as defined in any one of claims 1 to 10, the thermoelectric material layers of which have positive lateral thermoelectric power, and one or more second thermoelectric laminates as defined in any one of claims 1 to 10, the thermoelectric material layers of which have negative lateral thermoelectric power, which are closely attached to each other by the magnetic forces of their magnetized components, sandwiching their respective isolation layers, and electrically connected by the electrode regions of the isolation layers.

12. A thermoelectric device according to claim 11, wherein the thermoelectric material of the first thermoelectric stack is a magnetic material containing at least one selected from the group consisting of Sm-Co alloy, Co2MnGa alloy, Co2Mn(Al,Si) alloy, Co, Fe-Ga alloy, Fe-Al alloy, FePt alloy, FePd alloy, Fe3Sn2 alloy, and iron nitride (Fe4N), and the thermoelectric material of the second thermoelectric stack is a magnetic material containing at least one selected from the group consisting of NdFeB alloy, MnGa alloy, Fe, and Co-Gd alloy.

13. A thermoelectric device in which one or more first thermoelectric material layers having positive transverse thermoelectric power and one or more second thermoelectric material layers having negative transverse thermoelectric power are alternately stacked with an isolation layer sandwiched therebetween, wherein the first and second thermoelectric material layers have magnetization components perpendicular to the stacking surface and in the same direction, the isolation layer has electrode regions that are in close contact with insulating regions that electrically insulate the adjacent first and second thermoelectric material layers by the magnetic force of the magnetization components and that provide electrical conductivity between the insulating regions, and the electrode regions in contact with both sides of each of the first and second thermoelectric material layers are arranged in positions in each thermoelectric material layer that are spaced apart in a direction perpendicular to both the stacking direction and the direction in which a temperature gradient is applied.

14. A thermoelectric device according to claim 13, wherein the isolation layer extends from an end of the surface to be laminated to a side surface of the thermoelectric material layer, and the electrode region is provided in the extended region.

15. A thermoelectric device according to claim 13, wherein the first and second thermoelectric material layers adjacent to each other are stacked detachably with the isolating layer sandwiched therebetween by the magnetic force of the magnetized component.

16. A thermoelectric device according to any one of claims 13 to 15, wherein the first and second thermoelectric material layers have a three-dimensional shape that fits into the isolation layer on at least one surface that is in close contact with the electrode region of the isolation layer.

17. A thermoelectric device according to any one of claims 13 to 16, wherein the first thermoelectric material is a magnetic material containing at least one selected from the group consisting of a Sm-Co alloy, a Co2MnGa alloy, a Co2Mn(Al,Si) alloy, Co, a Fe-Ga alloy, a Fe-Al alloy, a FePt alloy, a FePd alloy, a Fe3Sn2 alloy, and iron nitride (Fe4N), and the second thermoelectric material is a magnetic material containing at least one selected from the group consisting of a NdFeB alloy, a MnGa alloy, Fe, and a Co-Gd alloy, as a main component.

18. A thermoelectric device as claimed in any one of claims 13 to 16, wherein at least one of the first and second thermoelectric material layers is a laminate comprising multiple layers of mutually different thermoelectric materials.

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