Power generation element, power generation cartridge, electronic device, and method for manufacturing power generation element

Abstract

The present invention provides a power generation element which is capable of efficiently supplying water to an intermediate layer and has enhanced power generation efficiency. Provided is a power generation element (100) for converting thermal energy into electric energy, the power generation element (100) comprising a multilayer structure (110) that has a layer structure layered in a specific direction. The multilayer structure (110) comprises at least one power generation unit structure (30). The power generation unit structure (30) comprises: a first electrode layer (2A) and a second electrode layer (2B) which are formed of metals that have different work functions from each other; and an intermediate layer (1) which is disposed between the first electrode layer (2A) and the second electrode layer (2B), and has a plurality of fine particles (11) dispersed therein. The fine particles (11) are composed of a transition metal oxide that has a perovskite crystal structure, and at least one of the first electrode layer (2A) and the second electrode layer (2B) has a plurality of water conveyance holes (20) that serve as paths for supplying moisture to the intermediate layer (1) from the outside of the electrode layer (2).

Description

Power generating element, power generating cartridge, electronic device, and method for manufacturing power generating element

[0001] The present invention relates to a power generating element that converts thermal energy into electrical energy between electrodes, a power generating cartridge, an electronic device, and a method for manufacturing the power generating element.

[0002] Thermoelectric conversion elements have been developed in the past.

[0003] International Publication No. 2023 / 038103

[0004] Such a conventional thermoelectric conversion element is, for example, a power generation element that does not require a temperature difference between electrodes when converting thermal energy into electrical energy, and is configured to include a first electrode, an intermediate portion provided on the first electrode and containing fine particles having a perovskite crystal structure, and a second electrode provided on the intermediate portion and having a work function different from that of the first electrode. The fine particles may contain, for example, titanium and zirconium.

[0005] However, in such thermoelectric conversion elements, it cannot necessarily be said that sufficient studies have been made on a configuration that stably generates power over time.

[0006] An object of the present invention is to provide a power generating element having an intermediate layer between electrodes, the intermediate layer containing fine particles of a transition metal oxide having a perovskite structure, which is capable of stably maintaining power generating efficiency.

[0007] The power generation element of the first invention is a power generation element for converting thermal energy into electrical energy, and comprises a laminated structure having a layer structure stacked in a predetermined direction, the laminated structure including at least one power generation unit structure, the power generation unit structure including a first electrode layer and a second electrode layer made of metals having different work functions from each other, and an intermediate layer provided between the first electrode layer and the second electrode layer and having a plurality of dispersed microparticles, each of the microparticles being a transition metal oxide having a perovskite crystal structure, and at least one of the first electrode layer and the second electrode layer having a plurality of water-conducting holes that serve as paths for supplying moisture from outside the electrode layer to the intermediate layer.

[0008] A power generating element according to a second aspect of the present invention is the power generating element of the first aspect of the present invention, wherein the water conducting holes are holes that extend from the outside of the first electrode layer, through the intermediate layer, to the outside of the second electrode layer.

[0009] The power generation element of the third invention is the same as that of the first or second invention, in which the power generation unit structures are stacked in a predetermined direction, and the water guide holes extend from the outer surface of one of the outermost layers of the power generation unit structures stacked in the predetermined direction, through the power generation unit structures, and to the other outermost layer of the power generation unit structures.

[0010] A fourth aspect of the present invention is a power generating element according to any one of the first to third aspects of the present invention, wherein the diameter of the water conduction holes is 1 nm or more, and the total cross-sectional area of ​​the plurality of water conduction holes is 50% or less of the area of ​​the first electrode layer or the second electrode layer in which the water conduction holes are formed.

[0011] A power generating element according to a fifth aspect of the present invention is the power generating element of any one of the first to third aspects of the present invention, wherein the first electrode layer, the second electrode layer and the intermediate layer are made of a flexible material.

[0012] The power generation element of the sixth invention is a power generation element for converting thermal energy into electrical energy, and comprises a laminated structure having a layer structure stacked in a predetermined direction, the laminated structure including at least one power generation unit structure, the power generation unit structure including a first electrode layer and a second electrode layer made of metals having different work functions from each other, and an intermediate layer provided between the first electrode layer and the second electrode layer and including a plurality of dispersed microparticles, each of the microparticles being a transition metal oxide having a perovskite crystal structure, and at least one of the first electrode layer and the second electrode layer having a plurality of water-conducting holes that serve as paths for supplying moisture from outside the electrode layer to the intermediate layer, the power generation element further comprising a sealing member for sealing the laminated structure, and a heat-resistant solvent containing moisture that is sealed in the sealing member together with the laminated structure.

[0013] The power generation element of the seventh invention is the sixth invention, wherein the heat-resistant solvent has a free mixing ratio with water and has a vapor pressure less than the internal pressure resistance of the sealing member when the temperature of the heat source of thermal energy is above the boiling point of water and below a predetermined temperature.

[0014] The power generating element according to an eighth aspect of the present invention is the power generating element according to any one of the first to seventh aspects of the present invention, wherein each of the fine particles has conductivity due to proton hopping conduction.

[0015] The power generation cartridge of the ninth invention comprises a power generation element for converting thermal energy into electrical energy, the power generation element comprising a laminated structure having a layer structure stacked in a predetermined direction, the laminated structure including at least one power generation unit structure, the power generation unit structure including a first electrode layer and a second electrode layer made of metals with different work functions and having flexibility, and an intermediate layer provided between the first electrode layer and the second electrode layer and having a plurality of dispersed microparticles, each of the microparticles being a transition metal oxide having a perovskite crystal structure, at least one of the first electrode layer and the second electrode layer having a plurality of water-conducting holes that serve as paths for supplying moisture from outside the electrode layer to the intermediate layer, and further comprising a container for accommodating the power generation element, the container having a structure that allows a heat medium that is a heat source of thermal energy and contains moisture to be supplied from outside.

[0016] The power generation cartridge of the tenth invention is the same as the ninth invention, except that the first electrode layer, the second electrode layer, and the intermediate layer are made of flexible materials, and the power generation element has a sheet shape and is rolled up and housed in a container.

[0017] An electronic device according to an eleventh aspect of the present invention is an electronic device that measures a physical quantity of an object to be measured, and includes a power generation element according to any one of the first to fifth aspects of the present invention, and a detection device that receives a supply of electrical energy from the power generation element and measures the physical quantity of the object to be measured.

[0018] A method for manufacturing a power generating element according to a twelfth aspect of the present invention is a method for manufacturing a power generating element that converts thermal energy into electrical energy, and includes: a first electrode layer forming step of forming a first electrode layer made of a first metal; and an intermediate layer forming step of forming an intermediate layer containing a plurality of dispersed transition metal oxide microparticles on a predetermined side of the first electrode layer, the microparticles being transition metal oxides having a perovskite crystal structure; a second electrode layer forming step of forming a second electrode layer on the predetermined side of the intermediate layer made of a second metal having a work function different from that of the first metal; and a water conduction hole forming step of forming water conduction holes that penetrate the first electrode layer, the intermediate layer, and the second electrode layer.

[0019] A method for manufacturing a power generating element according to a thirteenth aspect of the present invention is a method for manufacturing a power generating element that converts thermal energy into electrical energy, and includes a first electrode layer forming step of forming a first electrode layer made of a first metal, and an intermediate layer forming step of forming an intermediate layer containing a plurality of dispersed fine particles on a predetermined direction side of the first electrode layer, wherein the fine particles are a transition metal oxide having a perovskite crystal structure, and further includes a second electrode layer forming step of forming a second electrode layer on the predetermined direction side of the intermediate layer, the second electrode layer being made of a conductive polymer having a work function different from that of the first metal and having metal particles dispersed therein, and a water conduction hole forming step of selectively etching the metal particles of the second electrode layer to form water conduction holes from the second electrode layer to the intermediate layer.

[0020] According to the present invention, it is possible to stably maintain power generation efficiency in a power generating element having an intermediate layer containing fine particles of a transition metal oxide having a perovskite crystal structure.

[0021] 1 is a schematic cross-sectional view showing a power generating element 100 and a power generating device 200 according to the first embodiment. It is a schematic cross-sectional view taken along the line A-A in FIG. 1. It is a schematic cross-sectional view showing a power generating element 100 and a power generating device 200 according to the first embodiment. It is a schematic cross-sectional view showing a power generating element 100 and a power generating device 200 according to a comparative example. It is a schematic cross-sectional view showing the structure of an intermediate layer 1 of a power generating element 100 and a power generating device 200 according to a comparative example. It is a diagram showing the principle of power generation using proton hopping, in which thermal energy is converted into electrical energy by supplying water to an intermediate layer 1 containing fine particles 11 of a transition metal oxide having a perovskite structure. It is a flowchart showing a method for manufacturing a power generating element 100 and a power generating device 200 according to the first embodiment. (a) to (e) are schematic cross-sectional views showing the manufacturing steps of a power generating element 100 and a power generating device 200 according to the first embodiment. It is a schematic cross-sectional view showing a power generating element 100 and a power generating device 200 according to a modified example of the first embodiment. It is a schematic cross-sectional view showing the manufacturing steps of a power generating element 100 and a power generating device 200 according to a modified example of the first embodiment. 1 is a schematic cross-sectional view showing the power generating element 100 and the power generating device 200 according to a second embodiment. FIG. 2 is a schematic cross-sectional view showing the power generating unit structure 30 of the power generating element 100 and the power generating device 200 according to a third embodiment. FIG. 3 is a schematic cross-sectional view showing the power generating device 200 according to the third embodiment. FIG. 4 is a flowchart showing a manufacturing method for the power generating element 100 and the power generating device 200 according to the third embodiment. (a) to (g) are schematic cross-sectional views showing the manufacturing process for the power generating element 100 and the power generating device 200 according to the third embodiment. FIG. 4 is a specific example in which the power generating device 200 according to the third embodiment is used in a power generating cartridge.

[0022] Hereinafter, examples of a power generating element, a power generating device, a method for manufacturing a power generating element, and an electronic device as embodiments of the present invention will be described with reference to the drawings. In each figure, the height direction in which each electrode is stacked is defined as a first direction Z, one planar direction intersecting with, for example, orthogonal to, the first direction Z is defined as a second direction X, and another planar direction intersecting with, for example, orthogonal to, each of the first direction Z and the second direction X is defined as a third direction Y. Furthermore, the configurations in each figure are shown schematically for the purpose of explanation, and for example, the size of each component and the size comparison between components may differ from those shown in the figures. [First embodiment] (First embodiment: overview of power generating element 100 and power generating device 200)

[0023] A power generating element 100 according to a first embodiment will be outlined with reference to FIGS. 1 to 3. FIG.

[0024] Fig. 1 is a schematic cross-sectional view showing a power generating element 100 and a power generating device 200 according to the first embodiment. Fig. 2 is a schematic cross-sectional view taken along line A-A in Fig. 1. Fig. 3 is a schematic cross-sectional view showing the power generating element 100 according to the first embodiment. The aspects described in the first embodiment can be applied to other embodiments and modified examples.

[0025] 1 , the power generation device 200 includes a power generation element 100, a first wiring 4, and a second wiring 5. The power generation device 200 can be configured such that the power generation element 100 is connected to a load R via the first wiring 4 and the second wiring 5.

[0026] The power generating element 100 converts thermal energy from a heat source (not shown) into electrical energy.

[0027] The power generation device 200 including such a power generation element 100 is mounted or installed on, for example, a heat source, and outputs electrical energy generated from the power generation element 100 using thermal energy from the heat source to a load R via a first wiring 4 and a second wiring 5. One end of the load R is electrically connected to the first wiring 4, and the other end of the load R is electrically connected to the second wiring 5. The load R represents, for example, an electrical device such as a sensor or a communication device for communicating the detection results. The load R is driven, for example, using the power generation device 200 as a main power source or an auxiliary power source.

[0028] Examples of heat sources for the power generation device 200 include electronic devices or electronic components such as a CPU (Central Processing Unit), light-emitting elements such as LEDs (Light Emitting Diodes), engines of automobiles, factory production equipment, the human body, sunlight, and environmental temperature. For example, electronic devices, electronic components, light-emitting elements, engines, and production equipment are artificial heat sources. Human bodies, sunlight, and environmental temperature are natural heat sources. The power generation device 200 equipped with the power generation element 100 can be installed inside mobile devices such as IoT (Internet of Things) devices and wearable devices, as well as autonomous sensor terminals, and can be used as a replacement for or supplement to batteries. Furthermore, the power generation device 200 can also be applied to larger power generation devices such as solar power generation. (Power Generation Element 100)

[0029] The power generating element 100 converts, for example, thermal energy emitted by an artificial heat source or thermal energy possessed by a natural heat source into electrical energy to generate an electric current. The power generating element 100 can be provided not only in a power generating device 200 that receives heat from an external heat source, but also in a mobile device, a stand-alone sensor terminal, or the like. In this case, the power generating element 100 itself can serve as a substitute or auxiliary component for a battery in the mobile device, stand-alone sensor terminal, or the like.

[0030] 1, the power generating element 100 includes a laminated structure 110 having a layer structure stacked in a predetermined direction (first direction Z). Although not particularly limited, the power generating device 200 may have a configuration in which multiple laminated structures 110 are stacked, as will be described later.

[0031] The electrode layer 2 is provided with water-conducting holes 20. In Fig. 1 , at least one of the first electrode layer 2A and the second electrode layer 2B has a plurality of water-conducting holes 20 that serve as paths for supplying moisture from the outside of the electrode layer 2 to the intermediate layer 1. Here, the term "water-conducting hole" refers to a path for supplying moisture to the intermediate layer 1 from the outside of the power generating element 100.

[0032] Therefore, the water guide holes 20 may be provided as water guide holes 20A only in the first electrode layer 2A and the outer electrode layer 3A to supply moisture to the intermediate layer 1. Alternatively, the water guide holes 20 may be provided as water guide holes 20B only in the second electrode layer 2B and the outer electrode layer 3B to supply moisture to the intermediate layer 1.

[0033] 1 illustrates a configuration in which water guide holes 20 are provided through both the first electrode layer 2A and the second electrode layer 2B, the intermediate layer, and the outer electrode layer 3. That is, water guide holes 20 may be provided as water guide holes 20A and 20B in both the first electrode layer 2A and the second electrode layer 2B. In this case, as shown in FIG. 1 , water guide holes 20 can be configured to pass through electrode layer 2 from the outside of outer electrode layer 3 to intermediate layer 1.

[0034] 1 to 3, the plurality of water conduction holes 20 may also be formed in the intermediate layer 1 itself. In this case, in other words, as shown in Figures 1 to 3, the plurality of water conduction holes 20 are holes that connect from the outside of one electrode layer 2 (first electrode layer 2A), through the intermediate layer 1, to the outside of the other electrode layer 2 (second electrode layer 2B). When "water conduction holes" form a series of holes through the plurality of layers to the outside of the power generating element 100 in this way, they are called "through holes."

[0035] 2, the intermediate layer 1 extends in a plane along the second direction X and the third direction Y. The intermediate layer 1 is provided in the space between the first electrode layer 2A and the second electrode layer 2B.

[0036] As shown in Fig. 2, the intermediate layer 1 is an insulating layer 10 provided between a pair of electrode layers 2, and contains a plurality of dispersed fine particles (not shown). A plurality of water-conduction holes 20 are formed in the intermediate layer 1 in a cross section taken along line A-A. In Fig. 2, the water-conduction holes 20 are distributed at random positions in the cross section taken along line A-A. However, the water-conduction holes 20 may be arranged in a lattice pattern, for example, and the distribution of their positions is not limited to this.

[0037] 3, the laminated structure 110 includes at least one power generating unit structure 30. The power generating unit structure 30 has an intermediate layer 1 and a pair of electrode layers 2. The pair of electrode layers 2 is a first electrode layer 2A and a second electrode layer 2B. The power generating unit structure 30 has a configuration in which the second electrode layer 2B, the intermediate layer 1, and the first electrode layer 2A are arranged in this order in a predetermined direction (first direction Z). Note that the arrangement order of the electrode layer 2 and the intermediate layer 1 may be reversed.

[0038] The pair of electrode layers 2 are made of metals with different work functions. The definition of the work function and examples of metals with different work functions will be described later.

[0039] As shown in FIG. 3 , according to the configuration of the present embodiment in which the water guide holes 20 are provided, water can be efficiently supplied to the intermediate layer 1 containing the transition metal oxide microparticles 11 having a perovskite structure in the power generating element 100, thereby improving the power generation efficiency and realizing a power generating element 100 that generates stable power over time.

[0040] The power generating unit structure 30 or the laminated structure 110 of the power generating element 100 is used with the exterior filled with water or a medium containing water. Water is supplied to the intermediate layer 1 from the exterior of the electrode layer 2 of the laminated structure 110 through the water guide holes 20. The water supplied to the intermediate layer 1 contributes to efficient power generation. (Detailed Structure of the Power Generating Element 100 and the Power Generating Device 200 of the First Embodiment)

[0041] Next, the structures of the power generating element 100 and the power generating device 200 of the first embodiment will be described in detail with continued reference to Fig. 3. Fig. 3 shows an enlarged view of the minimum constituent part of the power generating unit structure 30 for power generation.

[0042] In the example shown in Figure 3, the water guide hole 20 penetrates from the outer surface of the outermost layer (e.g., the first electrode layer 2A) through the inside of the power generation unit structure 30 to another outermost layer (e.g., the second electrode layer 2B) of the power generation unit structure 30.

[0043] The particles 11 are transition metal oxides having a perovskite crystal structure. As an example, the particles 11 have conductivity due to proton hopping conduction. The transition metal oxides having a perovskite crystal structure and conductivity due to proton hopping conduction will be described later. (First Substrate 3A, Second Substrate 3B)

[0044] The conductive polymer layer 3 may be a substrate 3. The conductive polymer layer 3A may be a first substrate 3A. The conductive polymer layer 3B may be a second substrate 3B.

[0045] 1 , the first substrate 3A and the second substrate 3B may be made of, for example, a conductive material, such as iron, aluminum, copper, or an alloy of aluminum and copper. Furthermore, the first substrate 3A and the second substrate 3B may be made of, for example, a conductive semiconductor such as Si or GaN, or a conductive polymer. When the first substrate 3A and the second substrate 3B are made of a conductive material, wiring for connecting them to the first electrode layer 2A and the second electrode layer 2B is not required.

[0046] For example, if the first substrate 3A is a semiconductor, it may have a degenerated portion in contact with the first electrode layer 2A. In this case, the contact resistance between the first electrode layer 2A and the first substrate 3A can be reduced compared to when the first substrate 3A does not have a degenerated portion. Furthermore, the first substrate 3A may have a degenerated portion on a surface other than the surface in contact with the first electrode layer 2A. In this case, the contact resistance with the wiring (e.g., the first wiring 4) electrically connected to the first substrate 3A can be reduced.

[0047] 1 , semiconductors may be used for the first substrate 3A and the second substrate 3B. In this case, contact resistance can be reduced by providing a degenerated portion on the contact surfaces of the first substrate 3A and the second substrate 3B that come into contact as the power generating elements 100 are stacked.

[0048] The degenerate portion described above can be generated, for example, by ion-implanting a high concentration of n-type dopant into a semiconductor, or by coating a semiconductor with a material such as glass containing n-type dopant and then performing a heat treatment after the coating.

[0049] The impurities doped into the first semiconductor substrate 3A include known impurities such as P, As, and Sb for n-type and B, Ba, and Al for p-type. The impurity concentration in the degenerate portion is, for example, 1×10 １９ ions / cm ３ If so, electrons can be emitted efficiently.

[0050] For example, if the first substrate 3A is a semiconductor, the resistivity of the first substrate 3A is, for example, 1×10 －６ Ω・cm or more 1×10 ６ The specific resistance of the first substrate 3A is 1×10 －６ If the resistivity is less than Ω cm, it is difficult to select a material. ６ If it is greater than Ω·cm, there is a concern that current loss will increase.

[0051] Although the above description has been given of the case where the first substrate 3A is a semiconductor, the second substrate 3B may also be a semiconductor. In this case, the description will be omitted as it is the same as above. (Intermediate layer 1)

[0052] The intermediate layer 1 is provided on the second electrode layer 2B. The first electrode layer 2A is provided on the insulating layer 10 of the intermediate layer 1. The intermediate layer 1 also functions to maintain a gap between the first electrode layer 2A and the second electrode layer 2B in a predetermined direction (first direction Z). In the power generating element 100, which does not require a temperature difference between the electrodes when converting thermal energy into electrical energy, the amount of power generation can be increased by suppressing variations in the gap on the surface along the second direction X and the third direction Y.

[0053] In this regard, when forming the intermediate layer 1, if a process of introducing a liquid such as a solvent containing microparticles 11 into the gap between the second electrode layer 2B and the first electrode layer 2A is used, it is necessary to provide a support member or the like to maintain the gap. However, the formation of the support member or the like can increase the variation in the gap. In contrast, in the power generating element 100 of the first embodiment, the first electrode layer 2A is provided on the insulating layer 10 that constitutes the intermediate layer 1, so there is no need to provide a support member or the like to maintain the gap, and it is possible to suppress the variation in the gap caused by the accuracy of the formation of the support member or the like. This makes it possible to increase the amount of power generation.

[0054] In the power generating unit structure 30 of Fig. 3, the intermediate layer 1 can be made of a conductive and flexible material. Furthermore, as will be described later, the first electrode layer 2A, the second electrode layer 2B, and the external electrode layer 3 can also be made of flexible materials. When such materials are used, the power generating unit structure 30 and the power generating element 100 in which the power generating unit structures 30 are stacked also have flexibility as a whole. Here, in this specification, "flexibility" refers to the property of a material to flexibly bend under external force, and refers to the property of being flexible and not easily broken even when bent. A state in which there is little resistance to bending and the material can flexibly deform is referred to as "high flexibility."

[0055] The insulating layer 10 contains particles 11 exhibiting a perovskite structure and supports the first electrode layer 2A and the second electrode layer 2B. The particles 11 are fixed in a dispersed state in the insulating layer 10. In this case, movement of the particles 11 in the gap is suppressed. This prevents the particles 11 from being unevenly distributed on one side of the first electrode layer 2A or the second electrode layer 2B over time, which would otherwise cause a decrease in the amount of electron movement. This makes it possible to stabilize the amount of power generation.

[0056] Here, the "insulating layer" may be a layer that has insulating properties with respect to electric current but has the property of conducting heat. In fact, it is preferable that the layer has high thermal conductivity for conducting heat.

[0057] The insulating layer 10 is formed, for example, by solidifying a coated non-conductive material. The insulating layer 10 is, for example, solid. The insulating layer 10 may contain, for example, a residue of a diluent or an unsolidified portion of the non-conductive material.

[0058] The insulating layer 10 may contain, for example, one type of material, or may contain multiple materials depending on the application. The insulating layer 10 may be configured to include multiple layers containing different materials, or may include a configuration in which each layer is stacked. When the insulating layer 10 includes multiple layers, for example, each layer may have dispersed therein particles 11 containing different materials.

[0059] For the insulating layer 10, for example, a material described in ISO 1043-1 or JIS K 6899-1 may be used.

[0060] As described above, the material of the insulating layer 10 used in the intermediate layer 1 can be solidified with the microparticles 11 dispersed therein and can be a flexible insulating material. In this case, an organic polymer compound is preferable. When the insulator contains an organic polymer compound, the insulator can be formed flexibly, and therefore the power generating element 100 can be formed in a shape suitable for the intended use, such as curved or bent.

[0061] Examples of organic polymer compounds include polyimide, polyamide, polyester, polycarbonate, poly(meth)acrylate, radical polymerization type photo- or thermosetting resin, photocationic polymerization type photo- or thermosetting resin, epoxy resin, copolymer containing an acrylonitrile component, polyvinylphenol, polyvinyl alcohol, polystyrene, novolac resin, polyvinylidene fluoride, silicone resin, and mixtures thereof.

[0062] The plurality of fine particles 11 are dispersed within the insulating layer 10. The intermediate layer 1 is obtained, for example, by applying an insulator in which the fine particles 11 are dispersed to the second electrode layer 2B.

[0063] Alternatively, the insulating layer 10 may include, for example, a hydrophilic material. In this case, the water molecules can be easily maintained in close proximity to the fine particles. Materials such as polyvinyl alcohol, methyl cellulose, and polyethylene glycol are used as the insulating layer 10. Examples of hydrophilic materials include well-known materials such as nonionic polymers, anionic polymers, cationic polymers, acrylic resins, polyester resins, and polyurethane resins.

[0064] As another possibility, an inorganic substance may be used as the insulating layer 10. Examples of inorganic substances include porous inorganic substances such as zeolite and diatomaceous earth, as well as cage molecules.

[0065] The thickness of the insulating layer 10 is a finite value that defines the above-mentioned gap. The thickness of the insulating layer 10 is a finite value of, for example, 500 μm or less. The thickness of the insulating layer 10 affects the value and variation of the above-mentioned gap.

[0066] The particles 11 are nanoparticles, and their particle diameter is a finite value, for example, equal to or less than 1 / 10 of the thickness of the intermediate layer 1 in the predetermined direction Z(+). When the particle diameter of the particles 11 is equal to or less than 1 / 10 of the thickness of the intermediate layer 1 in the predetermined direction Z(+), it becomes easier to form the intermediate layer 1 containing the particles 11 between the first electrode layer 2A and the second electrode layer 2B. This improves workability when manufacturing the power generating element 100.

[0067] Here, "nanoparticles" refers to a substance containing multiple particles. The microparticles 11 are particles having a particle diameter of, for example, 2 nm or more and 100 nm or less. The microparticles 11 may include, for example, particles having a median diameter (median diameter: D50) of 3 nm or more and 8 nm or less, or may include, for example, particles having an average particle diameter of 3 nm or more and 8 nm or less. The median diameter or average particle diameter can be measured, for example, using a particle size distribution measuring instrument. As the particle size distribution measuring instrument, for example, a particle size distribution measuring instrument using dynamic light scattering (e.g., Zetasizer Ultra manufactured by Malvern Panalytical, etc.) may be used.

[0068] The fine particles 11 are made of a material having a perovskite crystal structure, and may contain, for example, at least one of titanium and zirconium as a constituent element.

[0069] The particles 11 may contain one type of material or may contain a plurality of materials depending on the application.

[0070] The fine particles 11 include, for example, a metal oxide. For example, the fine particles 11 including a metal oxide include zirconia (ZrO ２ ), titania (TiO ２ ), alumina (Al ２ O ３ ), iron oxide (Fe ２ O ３ , Fe ３ O ４ ), copper oxide (CuO), zinc oxide (ZnO), yttria (Y ２ O ３ ), niobium oxide (Nb ２ O ５ ), molybdenum oxide (MoO ３ ), indium oxide (In ２ O ３ ), tin oxide (SnO ２ ), tantalum oxide (Ta ２ O ５ ), tungsten oxide (WO ３ ), lead oxide (PbO), bismuth oxide (Bi ２ O ３ ), ceria (CeO ２ ), antimony oxide (Sb ２ O ５ , Sb ２ O ３ The fine particles 11 are made of, for example, a metal oxide of at least one element selected from the group consisting of metals and Si, such as barium titanate (BaTiO ３ ), strontium titanate (SrTiO ３ ), calcium titanate (CaTiO ３ ), lead titanate (PbTiO ３ ), tin titanate (SnTiO ３ ), cadmium titanate (CdTiO ３), and strontium zirconate (SrZrO ３ ) may be included.

[0071] As shown in FIG. 5 (described later), the fine particles 11 include, for example, a coating 11a on their surfaces. The thickness of the coating 11a is a finite value, for example, 20 nm or less. By providing such a coating 11a on the surfaces of the fine particles 11, it is possible to suppress aggregation when the fine particles 11 are dispersed in the insulating layer 10. It is also possible to increase the possibility that electrons will move between the first electrode layer 2A and the fine particles 11, between multiple fine particles 11, and between the second electrode layer 2B and the fine particles 11 by utilizing the tunneling effect, for example.

[0072] The coating 11a may be made of a material having, for example, a carboxyl group, a phosphate group, a thiol group, or a disulfide group. A material having a carboxyl group may be a fatty acid such as oleic acid. A material having a phosphate group may be a long-chain alkyl phosphate such as oleyl phosphate. A material having a thiol group may be an alkanethiol such as dodecanethiol. A material having a disulfide group may be an alkanedisulfide. (Proton Hopping)

[0073] A general description of "proton hopping conduction" will be given below. For example, as shown in FIG. 6, moisture contained in the atmosphere around the power generating element 100 is supplied to the intermediate layer 1. The water molecules supplied to the intermediate layer 1 can react with metal ions such as barium that constitute the perovskite structure. This causes hydronium (H ３ O ＋ ), and hydroxide ions (OH － ) is produced. The hydronium transfers a proton (H ＋ In this case, the rate of proton transfer tends to be much faster than ionic conduction.

[0074] The first metal of the first electrode layer 2A and the second metal of the second electrode layer 2B have different work functions. For example, the work function of the first electrode layer 2A is greater than the work function of the second electrode layer 2B. In this case, an electric field is generated in the gap. Due to the electric field in the gap generated based on the difference in work functions between the first electrode layer 2A and the second electrode layer 2B, protons move toward the low-potential side and hydroxide ions move toward the high-potential side. The protons then accept electrons from the electrode layer 2 on the low-potential side, and the hydroxide ions supply electrons to the electrode layer 2 on the high-potential side. This activates the movement of electrons between the first electrode layer 2A and the second electrode layer 2B. This makes it possible to improve the amount of power generation.

[0075] The fine particles 11 may have a work function between the work function of the first electrode layer 2 A and the work function of the second electrode layer 2 B. Alternatively, for example, the fine particles 11 may have a work function other than between the work function of the second electrode layer 2 B and the work function of the first electrode layer 2 A.

[0076] The term "work function" refers to the minimum energy required to extract electrons from a solid into a vacuum. The work function can be measured using, for example, ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), or Auger electron spectroscopy (AES).

[0077] In addition, when it is possible to utilize the fact that the work functions are different even if the metal materials are the same, the first electrode layer 2A and the second electrode layer 2B may be made of the same metal material. In this case, the work functions will be different due to differences in the surface conditions of the metal materials (for example, differences in the oxidation state or crystallinity of the surface).

[0078] The power generating element 100 utilizes an electron emission phenomenon that occurs between the first electrode layer 2A and the second electrode layer 2B, which have a work function difference, due to the supply of thermal energy from the outside. Therefore, the power generating element 100 emits more electrons as the absolute temperature increases.

[0079] The material of the first electrode layer 2A and the material of the second electrode layer 2B may be, for example, a material consisting of a single element such as iron, aluminum, or copper, or may be, for example, an alloy material consisting of two or more elements. The material of the first electrode layer 2A and the second electrode layer 2B may be, for example, a non-metallic conductive material. Examples of non-metallic conductive materials include carbon-based materials such as graphene and conductive polymers.

[0080] The thickness of the first electrode layer 2A and the second electrode layer 2B in the first direction Z is, for example, 4 nm to 1 μm, and may be, for example, 4 nm to 50 nm.

[0081] The gap, which indicates the distance between the first electrode layer 2A and the second electrode layer 2B, can be set arbitrarily by changing the thickness of the insulating layer 10. For example, by narrowing the gap, it is possible to increase the electric field generated between the first electrode layer 2A and the second electrode layer 2B, thereby increasing the amount of power generated by the power generating element 100. Furthermore, for example, by narrowing the gap, it is possible to reduce the thickness of the power generating element 100 in the first direction Z.

[0082] The gap defined by the thickness of the insulating layer 10 is a finite value, for example, 500 μm or less. The gap is, for example, 10 nm or more and 1 μm or less. For example, if the gap is 200 nm or less, it may lead to a decrease in the amount of power generation due to variations in the gap on the surface along the second direction X and the third direction Y. Furthermore, if the gap is larger than 1 μm, the electric field generated between the first electrode layer 2A and the second electrode layer 2B may be weakened. For these reasons, it is preferable that the gap is larger than 200 nm and 1 μm or less. [Comparative Example]

[0083] Next, a power generating element 100 and a power generating device 200 according to a comparative example will be described with reference to Fig. 4 and Fig. 5. As shown in Fig. 4, the power generating element 100 and the power generating device 200 according to the comparative example do not have water guide holes 20.

[0084] 5, the particles 11 are dispersed in the insulating layer 10, and for example, some of them may be exposed from the insulating layer 10. The particles 11 may be filled in gaps, for example, and the insulating layer 10 may be provided in the gaps between the particles 11. The particle diameter of the particles 11 is, for example, smaller than the gap. Here, too, the particle diameter of the particles 11 is set to a finite value, for example, 1 / 10 or less of the gap.

[0085] 5 , water is not supplied from the electrode layer 2, and therefore water is not easily supplied to the intermediate layer 1. For example, as shown in FIG. 5 , it is conceivable that water could be supplied from the side surface of the intermediate layer 1, but this would result in a lower water supply efficiency than when water guide holes 20 are provided in the electrode layer 2.

[0086] In other words, in the laminated structure of the electrode and intermediate layer as in the comparative example, water is supplied to the intermediate layer only from the peripheral portion of the electrode. Therefore, the insufficient water supply to the intermediate layer causes problems of insufficient output of the thermoelectric conversion element and a decrease in output over time. One possible way to address this issue is to make the electrodes comb-shaped, but this would result in a complicated wiring shape and would require high patterning costs.

[0087] For example, as a result of an experiment, when comparing power generation capacity in hot water at 85°C, in a state without through holes (comparison example), after one hour, the power generation capacity was about 700 nW / cm 2 After 15 hours, the output was 420 nW / cm 2 In contrast, in the case of the power generating element with the through holes (the power generating element of the first embodiment), the power output decreased to 850 nW / cm after one hour. 2 Even after 15 hours, the output was 784 nW / cm 2 was maintained.

[0088] The size of the water conduction holes is preferably at least large enough to allow the supply of water. A larger total area is preferable from the perspective of supplying water to the intermediate layer 1, but if the total area exceeds a certain level, the electrode area is sacrificed and output decreases. Therefore, the diameter of the water conduction holes is not particularly limited, but it is desirable for the diameter to be 1 nm or more and the total cross-sectional area to be 50% or less of the electrode area. That is, the diameter of each water conduction hole is 1 nm or more, and if the first electrode layer 2A has water conduction holes, the total cross-sectional area of ​​the multiple water conduction holes in the first electrode layer 2A is 50% or less of the area in the XY plane of the first electrode layer 2A. If the second electrode layer 2B has water conduction holes, the total cross-sectional area of ​​the multiple water conduction holes in the second electrode layer 2B is 50% or less of the area in the XY plane of the second electrode layer 2B. The method for forming the water conduction holes may be either a chemical method or a mechanical method, as described below. (Method for Manufacturing the Power Generation Element 100)

[0089] Next, a method for manufacturing the power generating element 100 according to the first embodiment will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a flowchart showing the method for manufacturing the power generating element 100 according to the first embodiment. Figs. 8(a) to (e) are schematic cross-sectional views showing the manufacturing process of the power generating element 100 according to the first embodiment.

[0090] The manufacturing method of the power generating element 100 according to the first embodiment is a manufacturing method of the power generating element 100 that converts thermal energy into electrical energy, and includes: a second electrode layer forming step of forming a second electrode layer 2B made of a second metal; and an intermediate layer forming step of forming an intermediate layer 1 containing a plurality of dispersed transition metal oxide microparticles 11 on a predetermined direction (first direction Z) side of the second electrode layer 2B, wherein the microparticles 11 are transition metal oxides having a perovskite crystal structure; a first electrode layer forming step of forming a first electrode layer 2A made of a first metal having a work function different from that of the second metal on the predetermined direction (first direction Z) side of the intermediate layer 1; and a water conduction hole forming step of forming water conduction holes 20 that penetrate the second electrode layer 2B, the intermediate layer 1, and the first electrode layer 2A.

[0091] Referring to FIG. 7 , in the second electrode formation step shown in step S10, for example, a second electrode layer 2B is formed. In the second electrode formation step, for example, as shown in FIG. 8( a), the second electrode layer 2B is formed on a substrate 3B. Although not particularly limited, the substrate 3B may be a conductive polymer layer 3B, and the second electrode layer 2B may be formed thereon by, for example, sputtering or vacuum deposition in a reduced pressure environment, or by using a known electrode formation technique. In the second electrode formation step, the substrate 3B may be a semiconductor substrate. Alternatively, instead of the second substrate 3B, the second electrode layer 2B may be formed by processing an elongated electrode material to a desired size. In this case, the second substrate 3B may not be used. However, by using a conductive polymer layer as the second substrate 3B, the power generating element 100 can be made flexible, as described below.

[0092] In the second electrode forming step, for example, when a film-like (sheet-like) member is used as the conductive polymer layer 3B, the second electrode layer 2B can be formed on the conductive polymer layer 3B, and the conductive polymer layer 3B and the second electrode layer 2B can be wound up in a roll. Thereafter, for example, in at least one of the intermediate layer forming step, the first electrode forming step, and the sealing material forming step described below, the roll can be cut to an area appropriate for the intended use.

[0093] In the intermediate layer formation process shown in step S11, as shown in FIG. 8B, for example, an intermediate layer 1 including an insulating layer 10 is formed on the second electrode layer 2B. In the intermediate layer formation process, for example, a non-conductive material containing dispersed fine particles 11 is applied to the surface of the second electrode layer 2B, and the non-conductive material is solidified to form the insulating layer 10. In this way, the intermediate layer 1 including the insulating layer 10 in which the fine particles 11 are dispersed is formed.

[0094] In the intermediate layer formation step, a non-conductive material is applied to the surface of the second electrode layer 2B by a known application technique such as screen printing, spin coating, etc. The thickness of the applied non-conductive material can be set arbitrarily depending on the design of the gap described above.

[0095] Alternatively, the intermediate layer forming step may involve mixing a fine particle material into the base material and solidifying it by laser irradiation, thereby forming the insulating layer 10 containing the fine particles 11, and thus the intermediate layer 1.

[0096] 8C, the first electrode formation step shown in step S12 forms a first electrode layer 2A on the intermediate layer 1. The first electrode layer 2A may be formed using a known electrode formation technique such as nanoimprinting.

[0097] Alternatively, the first electrode formation step may involve forming the first electrode layer 2A on the surface of the intermediate layer 1 by sputtering or vacuum deposition under reduced pressure. In this case, once the first electrode layer 2A is formed, the main surface of the first electrode layer 2A contacts the intermediate layer 1 without being exposed to the atmosphere or the like. This makes it possible to suppress fluctuations in the work function of the first electrode layer 2A. This allows for further stabilization of the amount of power generation.

[0098] In the first electrode formation step, for example, the first electrode layer 2A may be formed by bringing the surface of the first electrode layer 2A, which has been previously provided on the conductive polymer layer 3A, into contact with the surface of the intermediate layer 1. In this case, variations in the surface condition of the first electrode layer 2A caused by the surface condition of the intermediate layer 1 can be suppressed compared to when the first electrode layer 2A is formed directly on the surface of the intermediate layer 1. This makes it possible to increase the amount of power generation.

[0099] For example, when a film-like (sheet-like) member is used as the first substrate 3A, this can be realized by preparing a conductive polymer layer 3A on which the first electrode layer 2A is formed, and for example, the conductive polymer layer 3A and the first electrode layer 2A may be prepared in a rolled state. Thereafter, for example, before or after the sealing material forming step described below, the rolled state may be cut to an area according to the intended use.

[0100] In the first electrode formation step, for example, the intermediate layer 1 and the first electrode layer 2A may be heated after forming the first electrode layer 2A on the intermediate layer 1. Heating the intermediate layer 1 and the first electrode layer 2A may be performed, for example, instead of or in addition to the heating in the intermediate layer formation step. In this case, the surface of the intermediate layer 1 that contacts the first electrode layer 2A is easily flattened. This makes it possible to suppress the occurrence of a small gap between the intermediate layer 1 and the first electrode layer 2A. This makes it possible to increase the amount of power generation.

[0101] The second electrode forming step, the intermediate layer forming step, and the first electrode forming step constitute a laminated structure forming step.

[0102] In addition to the laminated structure forming step, a conductive polymer layer forming step may be provided in which a conductive polymer layer 3 having conductivity and flexibility is formed in a predetermined direction (first direction Z) of the laminated structure 110 .

[0103] Furthermore, a lamination step may be provided in which the laminate structure forming step and the conductive polymer layer forming step are repeated in sequence.

[0104] The water guide hole forming step shown in step S13 forms water guide holes 20 that penetrate the first electrode layer 2A, intermediate layer 1, and second electrode layer 2B. As shown in Figure 8(d) , in the water guide hole forming step, the water guide holes 20 that penetrate the first electrode layer 2A, intermediate layer 1, and second electrode layer 2B may be formed, for example, by a mechanical drilling method, a dry etching method, or the like.

[0105] In the sealing layer forming process shown in step S14, as shown in FIG. 8( e), for example, a sealing layer 6 is formed in contact with at least one of the first electrode layer 2A, the intermediate layer 1, and the second electrode layer 2B. The sealing layer 6 is formed using a known technique such as nanoimprinting. By carrying out the above-described steps, the power generating element 100 of this embodiment is formed. [Modification of the manufacturing method of the power generating element 100]

[0106] Next, a power generating element 100 according to a modified example of the first embodiment will be described with reference to Fig. 9 and Fig. 10. Descriptions that overlap with those of the first embodiment will be omitted. Fig. 9 is a schematic cross-sectional view showing a power generating element 100 according to a modified example of the first embodiment. Figs. 10(a) to 10(e) are schematic cross-sectional views showing manufacturing processes for the power generating element 100 according to the modified example of the first embodiment.

[0107] 9 and 10(a) to (g) below, the first electrode layer 2A and the second electrode layer 2B may be interchangeable. Similarly, the water guide hole 20A and the water guide hole 20B may be interchangeable. Similarly, the conductive polymer layer 3B may be interchangeable with the conductive polymer layer 3A. Furthermore, the terms "high work function" and "low work function" may be interchangeable.

[0108] 9, as an example, the water guide holes 20 are provided only in the first electrode layer 2A as water guide holes 20A. However, the water guide holes 20 may be provided only in the second electrode layer 2B as water guide holes 20B.

[0109] In the second electrode formation step shown in Figure 10(a), a second electrode layer 2B is formed on a substrate 3B. Although not particularly limited, the description will be given assuming that the substrate 3B is a conductive polymer layer 3B and that the second electrode layer 2B is formed thereon. That is, the second electrode layer 2B made of a second metal is formed on the conductive polymer layer 3B. In the intermediate layer formation step shown in Figure 10(b), an intermediate layer 10 including an insulating layer 10 is formed on the second electrode layer 2B.

[0110] 10(c), a first electrode layer 2A is formed on a predetermined direction side (first direction Z side) of the intermediate layer 1. The first electrode layer 2A is a conductive polymer layer having a work function different from that of the second metal, and has dispersed therein particles 21 made of a predetermined material, for example, metal particles 21. The first electrode layer 2A is formed using, for example, a material having a work function lower than that of the second electrode layer 2B.

[0111] In the first electrode forming step, the first electrode layer 2A is formed by, for example, applying a conductive polymer layer onto the intermediate layer 1.

[0112] 10( d ), in the water guide hole forming step, the metal particles 21 of the first electrode layer 2A are selectively etched to form the water guide holes 20 that penetrate the first electrode layer 2A. Here, the predetermined material means a material that can be selectively etched away with respect to the intermediate layer 1. When the particles 21 are metal particles 21, for example, wet etching using an acid that can etch the metal particles 21 is conceivable.

[0113] As shown in FIG. 10(e), a sealing layer 6 is formed in contact with at least one of the first electrode layer 2A, the intermediate layer 1, and the second electrode layer 2B.

[0114] According to the configuration of the power generating element 100 of the first embodiment as described above, water is stably supplied to the intermediate layer 1 through the water-conducting holes, so that it is possible to stably maintain power generation efficiency in a power generating element having an intermediate layer containing fine particles of transition metal oxide having a perovskite crystal structure. Note that the above-described improvement in power generation efficiency may be due to the proton hopping phenomenon. [Second embodiment] (Configuration in which the power generating element and heat-resistant solvent are sealed with a sealing member)

[0115] Next, a power generating element 100 and a power generating device 200 according to a second embodiment will be described with reference to Fig. 11. The aspects described in the second embodiment can be applied to, for example, a third embodiment described later.

[0116] As shown in FIG. 11 , the power generating device 200 of the second embodiment includes a power generating element 100 including a laminated structure 110 composed of an intermediate layer 1, an electrode layer 2, and a substrate 3 (for example, a conductive polymer layer 3), and a sealing member 7 that encloses the power generating element 100 together with a heat-resistant solvent 8.

[0117] As the sealing member 7, for example, a film material made by laminating resin and aluminum foil, such as that used in battery pouches, can be used.

[0118] The heat-resistant solvent 8 can be, for example, ethylene glycol or propylene glycol, which has a free mixing ratio with water. By adjusting the mixing ratio with water and the strength of the pouch material, it is possible to make the vapor pressure of the mixture of the heat-resistant solvent 8 and water less than the internal pressure resistance of the sealing member 7 when the temperature of the heat source in contact with the power generation device 200 is equal to or higher than the boiling point of water and equal to or lower than a predetermined temperature.

[0119] The power generating element 100 sealed in the sealing member 7 has the same configuration as that described in the first embodiment.

[0120] The heat source in contact with the power generation device 200 is, for example, a cylindrical pipe (a container 300 shown in FIG. 16, which will be described later) through which a fluid at a predetermined temperature (for example, a fluid above the boiling point of water) flows.

[0121] As explained in FIG. 6, the water molecules supplied to the intermediate layer 1 can react with metal ions such as barium that constitute the perovskite structure. This causes hydronium (H ３ O ＋ ), and hydroxide ions (OH － ) is produced. Then, hydronium (H ３ O ＋ ), and hydroxide ions (OH － ) receives electrons from electrode 2 or supplies electrons to the electrode, water is produced again by recombination.

[0122] 11 , in a power generating element 100 having an intermediate layer containing fine particles of transition metal oxide having a perovskite crystal structure, water is stably supplied to the intermediate layer 1 through the water conducting holes 20, and power generation efficiency can be stably maintained even when the power generating element 100 is in contact with a heat source whose temperature is equal to or higher than the boiling point of water.

[0123] Next, a power generating element 100 and a power generating device 200 according to a third embodiment will be described with reference to FIGS.

[0124] Fig. 12 is a schematic cross-sectional view showing a power generating unit structure 30 of a power generating element 100 according to the third embodiment. Fig. 13 is a schematic cross-sectional view showing a power generating device 200 in which power generating unit structures 30 according to the third embodiment are stacked. Fig. 14 is a flowchart showing a method for manufacturing the power generating element 100 and the power generating device 200 according to the third embodiment. Figs. 15(a) to 15(g) are schematic cross-sectional views showing the manufacturing process of the power generating element 100 and the power generating device 200 according to the third embodiment.

[0125] The power generating unit structure 30 shown in Fig. 12 is a power generating unit structure 30 in the case where the power generating element 100 has a stacked structure, and a plurality of such units can be stacked as shown in Fig. 13. Furthermore, when a plurality of power generating unit structures 30 are stacked to supply power to the outside as shown in Fig. 13, this is called a "power generating device 200." In the third embodiment, a configuration will be described in which the power generating element 100 is flexible and can be wound into a roll.

[0126] As shown in FIG. 12 , the power generation unit structure 30 of the power generation element 100 has a minimum configuration for generating power, which is made up of a first electrode layer 2-1 (2A-1) made of a first metal formed on a first main surface 3 a of the conductive polymer layer 3-1 (3A-1), an intermediate layer 1, and a second electrode layer 2-2 (2B-2) made of a second metal formed on a second main surface 3 b of the conductive polymer layer 3-2 (3B-2) facing the first main surface 3 a, with the intermediate layer 1 sandwiched between them.

[0127] Furthermore, as shown in FIG. 12, a first electrode layer 2-1 (2A-1) made of a first metal is formed on a first main surface 3a of the conductive polymer layer 3-2 (3B-2), and a second electrode layer 2-2 (2B-2) made of a second metal is formed on a second main surface 3b of the conductive polymer layer 3-1 (3A-1).

[0128] That is, in the power generation unit structure 30, a first electrode layer 2-1 (2A-1) (hereinafter, when referred to collectively, simply referred to as the "second electrode layer 2A") is formed on a first main surface 3a of the conductive polymer layer 3 (hereinafter, when referred to collectively, simply referred to as the "conductive polymer layer 3"), and a second electrode layer 2-2 (2B-2) (hereinafter, when referred to collectively, simply referred to as the "second electrode layer 2B") is formed on a second main surface 3b.

[0129] The first electrode layer 2A is formed so as to be mechanically supported by the first main surface 3a of the conductive polymer layer 3A, and the second electrode layer 2B is formed so as to be mechanically supported by the second main surface 3b that faces the first main surface 3a in a predetermined direction (first direction Z).

[0130] As described above, the first electrode layer 2A is formed so as to be mechanically supported on the first main surface 3a of the conductive polymer layer 3, and the second electrode layer 2B is formed so as to be mechanically supported on the second main surface 3b. This allows the conductive polymer layer 3 to have the mechanical strength of the first electrode layer 2A and the second electrode layer 2B, thereby enhancing bending durability and preventing tearing during the manufacturing process.

[0131] Here, "mechanically supported" means that, prior to the formation of the power generation unit structure 30, the first electrode layer 2A and the second electrode layer 2B, which are thin films, are each supported by the conductive polymer layer 3 so as to maintain their mechanical strength.

[0132] 13 , the power generation device 200 can be formed by stacking a plurality of power generation unit structures 30 in a predetermined direction (first direction Z). The power generation device 200 can be connected to a load R via a first wiring 4 and a second wiring 5. (Conductive polymer layer 2)

[0133] As described above, when producing the power generating unit structure 30, the conductive polymer layer 2 is used as the substrate.

[0134] The conductive polymer layer 2 is a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin or thermosetting resin contained in the conductive polymer layer 2 include polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polycycloolefin (PCO), polyethylene terephthalate (PET), polyethernitrile (PEN), polytetrafluoroethylene (PTFE), styrene butadiene rubber (SBR), polyacrylonitrile (PAN), polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVdF), epoxy resin, silicone resin, or a mixture thereof. From the viewpoint of electrical stability, polyethylene (PE), polypropylene (PP), and polymethylpentene (PMP) are preferred. These thermoplastic resins or thermosetting resins may be used alone or in combination. (Thickness of the Conductive Polymer Layer 2)

[0135] The thickness of the conductive polymer layer 2 is preferably 10 to 200 μm, more preferably 50 to 150 μm. A conductive resin layer thickness of 30 μm or more is preferable because the conductive resin layer has sufficient strength. Furthermore, a conductive resin layer thickness of 200 μm or less, preferably 100 μm or less, and more preferably 60 μm or less is preferable because the electrical resistance (volume resistivity) in the thickness direction is low. If the second electrode layer 3 and the first electrode layer 4 are thin metal layers, the durability to repeated bending may be poor and the tear strength may be low. Therefore, forming the conductive polymer layer 2 with an appropriate thickness allows the production of a power generating element 100 with high bending resistance and tear strength that can withstand the manufacturing process. (Preferable physical properties of resin made of conductive polymer material)

[0136] The conductive polymer layer 2 of the power generating element 100 according to this embodiment preferably has a volume resistivity of 500 Ω cm or less and a thickness of 50 to 150 μm. In addition, in consideration of flexibility, the conductive polymer layer 2 preferably has an elastic modulus of 30 MPa or less.

[0137] Furthermore, by thinning the conductive polymer layer 2 to a predetermined thickness or less, it is possible to reduce the total thickness when the power generating elements 100 are stacked. As a result, when the power generating device 200 made up of the power generating elements 100 is installed or attached to a heat source, there are fewer restrictions on the location where the power generating device 200 can be installed or attached to the heat source.

[0138] Furthermore, as a power generating element, it is desirable that the conductive polymer layer 2 have a high thermal conductivity. For example, the thermal conductivity is desirably 0.1 to 50 W / mK, and more desirably 5 W / mK or higher.

[0139] In order for the conductive polymer layer 2 to exhibit sufficient conductive function, it is preferable that the conductive filler is uniformly dispersed in the conductive polymer layer 2 .

[0140] Examples of conductive filler materials include, but are not limited to, metals (nickel, aluminum, stainless steel (SUS), silver, copper, titanium, etc.), conductive carbon (graphite, carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, etc.), carbon nanotubes, etc.), and mixtures thereof. The conductive filler may be a particulate ceramic material or a resin material coated with a conductive material (a metal one of the above-mentioned conductive fillers) by plating or the like. These conductive fillers may be used alone or in combination of two or more. Furthermore, alloys or metal oxides of these may also be used.

[0141] Among conductive fillers, metals and conductive carbons are preferred from the viewpoint of electrical stability. Among metals, nickel particles are preferred. Among conductive carbons, carbon black or a mixture of carbon black and carbon nanotubes is preferred, and acetylene black or a mixture of acetylene black and carbon nanotubes is more preferred.

[0142] The shape (form) of the conductive filler is not limited to a particulate form, and may be a form other than a particulate form, such as a carbon nanotube, which is a form that has been put into practical use as a so-called filler-based conductive material.

[0143] In addition to the thermoplastic resin or thermosetting resin and the conductive filler, other components (dispersants, crosslinking accelerators, crosslinking agents, colorants, ultraviolet absorbers, plasticizers) and the like can be added to the conductive polymer layer 2 as appropriate, within the range that does not impair the effects of the present invention.

[0144] FIG. 14 is a flowchart showing a method for manufacturing a power generating element 100 according to the third embodiment of the present invention.

[0145] 15(a) to 15(f) are schematic cross-sectional views showing the manufacturing process of the power generating element 100 according to the third embodiment of the present invention.

[0146] As shown in FIG. 14, the flowchart showing the method for manufacturing the power generating element 100 according to the third embodiment includes steps S20 to S25.

[0147] Steps S20 to S22 in Fig. 14 represent a base sheet forming step. The base sheet forming step includes a conductive polymer layer forming step (step S20), a first electrode forming step (step S21), and a second electrode forming step (step S22).

[0148] As shown in steps S20 to S22, in the base sheet forming step, a plurality of sheet-shaped base sheets 40 are formed (FIGS. 15(a) to 15(c)). In the base sheet forming step, the number of base sheets to be laminated is previously manufactured.

[0149] As shown in step S20, in the conductive polymer layer forming step, conductive and flexible conductive polymer layer 3 is formed in a sheet shape (FIG. 5(a)).

[0150] Subsequently, as shown in step S21, in the first electrode formation step, a second electrode layer 2A made of a first metal having a first work function is formed on the first main surface 3a of the conductive polymer layer 3 so as to be mechanically supported by the conductive polymer layer 3 ( FIG. 5(b) ).

[0151] As shown in step S22, in the second electrode formation step, a second electrode layer 2B made of a second metal having a second work function is formed on a second main surface 2b opposite to the first main surface 3a so as to be mechanically supported by the conductive polymer layer 3. The second work function is different from the first work function.

[0152] Steps S20 to S22 form a plurality of sheet-like base sheets 40 (FIG. 15(c)). For example, a plurality of sheet-like conductive polymer layers 3 of a predetermined size may be prepared, and electrode layers 2A, 2B may be formed on each main surface of each sheet-like conductive polymer layer 3. Alternatively, a sheet-like base sheet 40 having a large area may be formed first, and then cut and divided into desired sizes to form a plurality of base sheets 40 of the same size.

[0153] The formation of the first electrode layer 2A and the second electrode layer 2B is not particularly limited, but a film formation method capable of forming a metal layer on the surface of a resin, such as a vacuum deposition method or a sputtering method, or an electroless plating method, can be used.

[0154] As mentioned above, "mechanically supported" means that at the stage when the base sheet 40 is formed before the laminated structure is formed, the first electrode layer 2A and the second electrode layer 2B are supported by the conductive resin layer 3 so as to maintain mechanical strength.

[0155] As shown in step S23, in the laminated structure formation process, an intermediate layer 1 is formed on the second electrode layer 2B of the base sheet 40 (FIG. 5(d)), and then the base sheet 40 and the intermediate layer 1 are repeatedly laminated, thereby forming a plurality of unit structures in sequence to form a laminated structure 50 (FIGS. 5(e) and (f)).

[0156] That is, the first electrode layer 2A of one of the plurality of base sheets 40 is brought into contact with the intermediate layer 1 formed on the second electrode layer 2B of another base sheet 40. The other base sheet corresponds to the role of the one base sheet in the next unit structure forming step, and the same lamination process is repeated.

[0157] At least the following two methods are conceivable as a process for solidifying the insulating layer 10 in the intermediate layer 1.

[0158] First, after applying the intermediate layer onto the electrode, solidification (solvent drying, curing by light or heat) is carried out layer by layer. This process is preferable when the intermediate layer contains a solvent.

[0159] Alternatively, secondly, after the step of sequentially forming and stacking unit structures is completed, it is possible to perform a process of solidifying the insulating layer 10 in the intermediate layer 1 by, for example, a heat treatment.

[0160] However, the process for solidifying the insulating layer 10 is not limited to such a processing process, and the timing of solidification can be adjusted depending on the characteristics of the material used to form the insulating layer 10.

[0161] As shown in step S24, after forming the laminated structure 110, in the outermost electrode forming step, an outermost electrode layer 5 of a predetermined thickness is adhered to the first electrode layer 2A and the second electrode layer 2B that are the outermost layers of the finally formed laminated structure, or an outermost electrode layer is additionally formed. Note that instead of providing the electrode layer 5, the laminated structure forming step may be performed without initially providing the first electrode layer 2A or the second electrode layer 2B that correspond to the outermost layers on the outermost base sheet 40, thereby resulting in a configuration in which the conductive polymer layer 3 appears on the surface.

[0162] 15(d), it is also possible to first adhere the base sheet 40 to the outermost electrode layer having a predetermined thickness, or to form the outermost electrode layer 5 on the first electrode layer 2A of the base sheet 40. Then, the intermediate layer 1 may be formed on the second electrode layer 2B of the base sheet 40.

[0163] 15(g), in the water guide hole forming step shown in step S25, water guide holes 20 are provided that penetrate the first electrode layer 2A, intermediate layer 1, second electrode layer 2B, conductive polymer layer 3, and outermost electrode layer of the laminated structure 50. Assuming that the outermost electrode layer has been formed, the "water guide hole forming step" can be, for example, a step similar to the water guide hole forming step (S13) described with reference to FIG.

[0164] By the steps described above, it is possible to form the power generating element 100 having the layered structure shown in FIG.

[0165] As described above, according to the manufacturing method of this embodiment, it is possible to easily manufacture the power generating element 100 that has high bending durability and can be placed on the surface of a curved heat source or can be wound.

[0166] 15(a) to 15(c), the conductive polymer layer 3 of the power generating element 100 according to the third embodiment is a sheet-like material, and the first electrode layer 2A is formed in advance on the first main surface 2a of the conductive polymer layer 3 so as to be mechanically supported by the conductive polymer layer 3, before the formation of the laminated structure 50. The second electrode layer 2B is formed in advance on the second main surface 2b of the conductive polymer layer 3 so as to be mechanically supported by the conductive polymer layer 3, before the formation of the laminated structure 50.

[0167] As shown in FIG. 15( d ), the intermediate layer 1 of the power generating element 100 according to the third embodiment is formed by applying a material in which nanoparticles 11 are dispersed in an insulating material onto the second electrode layer 2B formed on the sheet-like conductive polymer layer 3, and then solidifying the material into a flexible state.

[0168] As a result, the first electrode layer 2A, the second electrode layer 2B, and the conductive polymer layer 3 are also flexible, and therefore, according to this embodiment, it is possible to easily manufacture the power generating element 100 that has high bending durability and can be placed on the surface of a curved heat source A.

[0169] Furthermore, by forming the first electrode layer 2A and the second electrode layer 2B so as to be mechanically supported by the conductive polymer layer 3, it is possible to suppress a decrease in tear strength due to the first electrode layer 2A and the second electrode layer 2B being thin layers, and it is possible to suppress unintentional tearing of the first electrode layer 2A and the second electrode layer 2B during the manufacturing process of the power generation element 100.

[0170] FIG. 16 shows a specific example in which the power generating device 200 according to the third embodiment is used in a power generating cartridge.

[0171] In the following description, the power generating element 100 of the power generating cartridge 200 according to the third embodiment has a flexible sheet shape, is rolled up, and is housed in a cylindrical container 300 .

[0172] The power generation cartridge is, for example, a power generation device 200 in which the power generation element 100 described with reference to Fig. 1 or 13 is formed into a sheet and wound into a roll with the first electrode layer 2A on the inside and the second electrode layer 2B on the outside, and housed in a water-permeable outer cylinder 300. The outermost electrode may be the outermost electrode 3 or 5, as described with reference to Figs. 1, 14, and 15. Furthermore, as shown in Fig. 16, the sheet may be processed so that the first electrode layer 2A appears on the outside at the outermost part of the roll, allowing the electrodes to be pulled out from the first electrode layer 2A and the second electrode layer 2B.

[0173] Alternatively, electrodes may be separately drawn out from the first electrode layer 2A and the second electrode layer 2B to the outside.

[0174] The power generation cartridge can be placed in a heat source such as hot water while still housed in the cylindrical or tubular container 300 .

[0175] The container 300 is provided with, for example, fine water-conducting holes (not shown). When the container 300 is immersed in hot water, the hot water is supplied from the water-conducting holes into the container 300. Therefore, the hot water is supplied to the intermediate layer 1 from the water-conducting holes 20 provided in the first electrode layer 2A or the second electrode layer 2B of the power generation device 200, and the power generation device 200 generates electricity.

[0176] The power generating cartridge according to the third embodiment further includes a container 300 for accommodating the power generating element 100, and the container 300 has a structure that allows a heat medium containing moisture, which is a heat source for thermal energy, to be supplied from the outside.

[0177] The electric power generated by the power generation device 200 is output to the load R through the first wiring 4 and the second wiring 5 as shown in FIGS.

[0178] Here, as an example, the detection device R can be configured to measure a physical quantity of the surface of the target object, such as the surface temperature.

[0179] As a method for measuring the temperature, well-known temperature measurement methods such as infrared rays and thermocouples can be used. Furthermore, since the detection device R functions as an IoT (Internet of Things) device, it is possible to transmit measurement result data to the outside, for example, by a predetermined wireless communication method. Power for such communication is also supplied from the power generation device 200.

[0180] Furthermore, the physical quantity measured by the detector R is not limited to temperature. Therefore, the detector R may be a temperature detector, a current detector, a voltage detector, a pressure detector, or any other device that detects other physical quantities.

[0181] As described above, several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims.

[0182] The number, shape, and position of the water-conducting holes are not particularly limited as long as they function as paths for supplying moisture from the outside of the electrode layer to the intermediate layer. For example, the water-conducting holes may be slits that extend elongately in one direction in a plan view.

[0183] REFERENCE SIGNS LIST 100 Power generating element 1 Intermediate layer 10 Insulating layer 11 Fine particles 2 (2A) First electrode layer 2 (2B) Second electrode layer 20 Water guide hole 21 Metal particle 3 Conductive polymer layer 4 First wiring 5 Second wiring 6 Sealing layer 7 Sealing member

Claims

1. A power generation element for converting thermal energy into electrical energy, comprising a laminated structure having a layer structure stacked in a predetermined direction, the laminated structure including at least one power generation unit structure, the power generation unit structure including: a first electrode layer and a second electrode layer made of metals having different work functions; and an intermediate layer provided between the first electrode layer and the second electrode layer and having a plurality of dispersed fine particles, each of the fine particles being a transition metal oxide having a perovskite crystal structure, and at least one of the first electrode layer and the second electrode layer having a plurality of water-conducting holes that serve as paths for supplying moisture from outside the electrode layers to the intermediate layer.

2. The power generating element according to claim 1, wherein the water conducting hole is a hole that extends from the outside of the first electrode layer, through the intermediate layer, to the outside of the second electrode layer.

3. A power generation element as described in claim 2, wherein the power generation unit structures are stacked in the predetermined direction, and the water guide holes are water guide holes that extend from the outer surface of one outermost layer of the plurality of power generation unit structures stacked in the predetermined direction, through the plurality of power generation unit structures, to the other outermost layer of the plurality of power generation unit structures.

4. A power generating element according to any one of claims 1 to 3, wherein the diameter of the water guide hole is 1 nm or more, and the total cross-sectional area of ​​the plurality of water guide holes is 50% or less of the area of ​​the first electrode layer or the second electrode layer in which the water guide holes are formed.

5. A power generating element according to any one of claims 1 to 3, wherein the first electrode layer, the second electrode layer and the intermediate layer are made of a flexible material.

6. A power generation element for converting thermal energy into electrical energy, comprising: a laminated structure having a layer structure stacked in a predetermined direction, the laminated structure including at least one power generation unit structure, the power generation unit structure including: a first electrode layer and a second electrode layer made of metals having different work functions; and an intermediate layer provided between the first electrode layer and the second electrode layer and including a plurality of dispersed fine particles, each of the fine particles being a transition metal oxide having a perovskite crystal structure, at least one of the first electrode layer and the second electrode layer having a plurality of water-conducting holes that serve as paths for supplying moisture from outside the electrode layer to the intermediate layer, a sealing member for sealing the laminated structure, and a heat-resistant solvent containing moisture that is sealed in the sealing member together with the laminated structure.

7. The power generation element described in claim 6, wherein the heat-resistant solvent has a free mixing ratio with water and has a vapor pressure lower than the internal pressure resistance of the sealing member when the temperature of the heat energy source is equal to or higher than the boiling point of water and equal to or lower than a predetermined temperature.

8. A power generating element according to any one of claims 1 to 7, wherein each of the particles has conductivity due to proton hopping conduction.

9. A power generation cartridge comprising: a power generation element for converting thermal energy into electrical energy, the power generation element comprising a laminated structure having a layer structure laminated in a predetermined direction, the laminated structure comprising at least one power generation unit structure, the power generation unit structure comprising: a first electrode layer and a second electrode layer made of metals having different work functions and having flexibility; and an intermediate layer provided between the first electrode layer and the second electrode layer and having a plurality of dispersed fine particles, each of the fine particles being a transition metal oxide having a perovskite crystal structure, at least one of the first electrode layer and the second electrode layer having a plurality of water-conducting holes that serve as paths for supplying moisture from outside the electrode layer to the intermediate layer, and further comprising a container for accommodating the power generation element, the container having a structure that allows a heat medium containing moisture, which is a heat source of the thermal energy, to be supplied from outside.

10. The power generating cartridge described in claim 9, wherein the first electrode layer, the second electrode layer and the intermediate layer are made of a flexible material, and the power generating element has a sheet shape and is rolled up and housed in the container.

11. An electronic device for measuring a physical quantity of an object to be measured, comprising: a power generating element according to any one of claims 1 to 5; and a detection device that receives a supply of electrical energy from the power generating element and measures the physical quantity of the object to be measured.

12. A method for manufacturing a power generation element that converts thermal energy into electrical energy, comprising: a first electrode layer forming step of forming a first electrode layer made of a first metal; and an intermediate layer forming step of forming an intermediate layer containing a plurality of dispersed transition metal oxide fine particles on a predetermined direction side of the first electrode layer, the fine particles being transition metal oxides having a perovskite crystal structure; a second electrode layer forming step of forming a second electrode layer on the predetermined direction side of the intermediate layer made of a second metal having a work function different from that of the first metal; and a water conduction hole forming step of forming water conduction holes that penetrate the first electrode layer, the intermediate layer, and the second electrode layer.

13. A method for manufacturing a power generation element that converts thermal energy into electrical energy, comprising: a first electrode layer forming step of forming a first electrode layer made of a first metal; and an intermediate layer forming step of forming an intermediate layer containing a plurality of dispersed fine particles on a predetermined direction side of the first electrode layer, wherein the fine particles are a transition metal oxide having a perovskite crystal structure; a second electrode layer forming step of forming a second electrode layer on the predetermined direction side of the intermediate layer, the second electrode layer being made of a conductive polymer having a work function different from that of the first metal and containing dispersed metal particles; and a water conduit forming step of selectively etching the metal particles of the second electrode layer to form water conduits from the second electrode layer to the intermediate layer.

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