Cooling source and cooling device using thermal power generation element

Abstract

It uses a thermal power generation element that does not require a temperature gradient. [Solution] The cooling device 100 has a plurality of reference cells 30, each of which contains a heat-utilization power generation element 1 having a basic configuration in which a material layer 5 containing a thermoelectric conversion material and an electrolyte layer 4 containing an electrolyte are stacked in a container 20 formed from a highly thermally conductive material, and a control unit 62 that controls the power generation of the heat-utilization power generation element 1 contained in each reference cell 30. The control unit 62 sequentially switches between the reference cells 30 that contain the heat-utilization power generation element 1 to be generated, and performs cooling by power generation of the heat-utilization power generation element 1 continuously or intermittently.

Description

[Technical Field]

[0001] The present invention relates to a cooling source using a thermal power generation element and a cooling device. [Background technology]

[0002] One method of generating electricity using thermal energy is to use the Seebeck effect, which converts thermal energy into electrical energy through thermoelectric conversion using a temperature gradient.

[0003] Patent Documents 1 and 2 propose a semiconductor-sensitized thermal cell that generates electricity by utilizing an oxidation-reduction reaction caused by thermally excited charges in a semiconductor. Hereinafter, this type of thermal power generation element will also be referred to as an "STC." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6803076 [Patent Document 2] International Publication No. 2022 / 191101 Summary of the Invention [Problem to be solved by the invention]

[0005] STC is a thermal power generation element that does not require a temperature gradient, and can generate power even when installed in an isothermal environment. This type of thermal power generation element that does not require a temperature gradient can be made smaller and lighter than a thermal power generation element that does require a temperature gradient, as it does not require cooling equipment. Thermal power generation elements that do not require a temperature gradient are expected to be used in a variety of situations. [Means for solving the problem]

[0006] The present disclosure provides: This is a cooling source that uses a thermal power generation element that is not dependent on a temperature gradient.

[0007] Another aspect of the present disclosure is a thermal power generation element having a basic configuration in which a first layer connected to a first electrode and containing a thermoelectric conversion material and a second layer connected to a second electrode and containing an electrolyte are stacked; a reference cell in which the thermal power generation element is housed in a container made of a material with high thermal conductivity; a control device that controls the power generation of the thermal power generation element, a plurality of the reference cells; The control device is a cooling device configured to sequentially switch between reference cells that house the heat-utilizing power generation elements that generate power, and to continuously or intermittently perform cooling by power generation of the heat-utilizing power generation elements. [Effects of the Invention]

[0008] According to the present invention, the heat absorbed by the thermal power generation element when it generates power can be used for cooling. The thermal power generation element returns to a state where it can generate power after discharging, so it can serve as a cooling source that can be used repeatedly. Furthermore, by configuring a cooling device that includes multiple reference cells that house thermal power generation elements, the generated electricity can be utilized and the thermal power generation elements can be cooled by absorbing heat by sequentially switching between the reference cells that generate electricity. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram illustrating the configuration of a thermal power generation element and the mechanism of power generation. FIG. [Figure 2] 1 is a schematic diagram illustrating the configuration of a thermal power generation element and the mechanism of power generation. FIG. [Figure 3] FIG. 2 is a schematic diagram showing the waveform of the output voltage of a thermal power generation element. [Figure 4] FIG. 2 is a diagram illustrating an example of the configuration of a cooling device. [Figure 5]FIG. 1 is a schematic diagram of a test device for performing a confirmation test using a test cell. [Figure 6] 6 is a graph summarizing the relationship between load conditions and temperature differences when a confirmation test was carried out using the test cell shown in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0010] First, definitions of terms used in this specification will be explained. The term "cooling source" refers to an element that absorbs heat from the surroundings to lower its temperature, and functions as a destination for thermal energy. In this embodiment, a thermal power generation element that absorbs heat from the surroundings to lower its temperature and generates power using the absorbed thermal energy, without relying on the temperature gradient of the installation environment, is given as an example of a cooling source.

[0011] "Thermoelectric conversion material" means a material that can convert thermal energy into electrical energy without depending on the temperature gradient of the installation environment. For example, when the "thermoelectric conversion material" is a semiconductor, it means a semiconductor that can generate thermally excited charges when placed in a predetermined temperature environment, even if there is no temperature difference.

[0012] A "cooling device" is a device that includes at least a plurality of reference cells that house thermal power generation elements as cooling sources, and a control device that controls the power generation by the thermal power generation elements housed in each reference cell. In a cooling device, the control device sequentially switches between the thermal power generation elements that generate power, thereby enabling the device to perform both the function of lowering temperature by absorbing heat from the surroundings and the function of generating power by absorbing thermal energy. Therefore, in this specification, "cooling device" refers to a device that has both the function of cooling by absorbing thermal energy and the function of generating power by absorbing thermal energy.

[0013] "Switching the reference cells to generate electricity in sequence" means that when each of the reference cells that make up the "cooling device" contains one thermal power generation element, the thermal power generation element to generate electricity is switched in sequence.

[0014] Hereinafter, an embodiment of the present invention will be described taking as an example a semiconductor-sensitized thermal power generating element 1 that generates power by utilizing an oxidation-reduction reaction caused by thermally excited charges in a semiconductor. FIG. 1 is a schematic diagram illustrating the configuration of a thermal power generation element 1 and the mechanism of power generation.

[0015] As shown in Figure 1, the thermoelectric power generation element 1 (STC) is a semiconductor-sensitized battery having a basic configuration in which an electrolyte layer 4 in which charge-transporting ion pairs can move and a material layer 5 containing a thermoelectric conversion material are sandwiched between a sheet-shaped positive electrode 2 (electrode) and a sheet-shaped negative electrode 3 (electrode).

[0016] [electrode] The positive electrode 2 and the negative electrode 3 are formed of a material that (a) can transport electrons and (b) is insoluble in the electrolyte. Examples of materials that can be used for the electrodes include titanium, gold, platinum, silver, copper, tin, tungsten, niobium, tantalum, aluminum, graphene, molybdenum, indium, vanadium, rhodium, niobium, chromium, nickel, and carbon. The metals exemplified here may be used alone or in alloys with other metals, such as stainless steel, or any combination of the exemplified metals. The positive electrode 2 and the negative electrode 3 may be made of different materials (metals), or may be made of the same material (metal).

[0017] Furthermore, other materials such as fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), zinc oxide (ZnO), indium oxide (In2O3), tin oxide (SnO2), IZO (In-Zn-O), or IGZO (In-Ga-Zn-O) may also be used as the electrode constituent material.

[0018] [Electrolyte layer] The electrolyte layer 4 may be any layer containing an electrolyte through which two ions of a charge-transporting ion pair (described later) can move. For example, the electrolyte is a solid electrolyte or an electrolyte solution. The electrolyte contained in the electrolyte layer 4 may have an oxidation-reduction level (energy level of oxidation-reduction) at an appropriate position relative to the valence band position (energy level of the valence band) of the semiconductor contained in the material layer 5, and may be any electrolyte that allows charge-transporting ion pairs to move back and forth within the electrolyte. The electrolyte is formed so that the semiconductor contained in the material layer 5 generates a sufficient number of thermally excited electrons (e - It is preferable that the material is physically and chemically stable at the temperature at which the electrons (h) and holes (h) are generated (hereinafter also referred to as the "power generation temperature").

[0019] Depending on the temperature, the electrolyte takes the form of an electrolyte solution (liquid electrolyte) or a solid electrolyte. In this specification, the term "electrolyte solution" refers to a solution (liquid) state at the power generation temperature, and the term "solid electrolyte" refers to a solid state electrolyte in which charge-transporting ion pairs can move at the power generation temperature. The electrolyte may also include a molten salt, an ionic liquid, or a deep eutectic solvent. Molten salts are salts consisting of cations and anions in a molten state, while ionic liquids are molten salts with relatively low melting points (for example, 100°C or less, or 150°C or less). In this specification, a molten salt in a solid state is referred to as a "solid electrolyte," and a molten salt in a solution state is referred to as an "electrolyte solution (liquid electrolyte)." Specific examples of electrolyte solutions (liquid electrolytes), solid electrolytes, and molten salts are given below, but they may overlap with each other.

[0020] The electrolyte solution used is in a solution (liquid) state at the above-mentioned power generation temperature. As an example, a solution containing a compound (electrolyte) that generates ion species such as methoxide ions, hydrogen ions, ammonium ions, pyridinium ions, lithium ions, sodium ions, potassium ions, calcium ions, magnesium ions, aluminum ions, iron ions, copper ions, zinc ions, cobalt ions, fluoride ions, cyanide ions, thiocyanate ions, chloride ions, acetate ions, sulfate ions, carbonate ions, phosphate ions, hydrogen carbonate ions, and bromine ions can be used as the electrolyte solution.

[0021] The solid electrolyte is preferably an electrolyte that exists in a solid state at high temperatures, which allows power generation in a high-temperature environment. As an example, a sodium ion conductor, a copper ion conductor, a lithium ion conductor, a silver ion conductor, a hydrogen ion conductor, a strontium ion conductor, an aluminum ion conductor, a fluorine ion conductor, a chloride ion conductor, or an oxide ion conductor can be used as the solid electrolyte.

[0022] More specifically, RbAg4I5, Li3N, Na2O·11Al2O3, Sr-β alumina, Al2(WO4)3, PbF2, PbCl2, (ZrO2) 0.9 (Y2O3) 0.1 , (Bi2O3) 0.75 (Y2O3) 0.25 , CuZr2(PO4)3, CuTi2(PO4)3, Cu x Nb 1-x Ti 1+x (PO4)3, H 0.5 Cu 0.5 Zr2(PO4)3, Cu 1+x Cr x Ti 2-x (PO4)3, Cu 0.5 TiZr(PO4)3, CuCr2Zr(PO4)3, Cu2ScZr(PO4)3, CuSn2(PO4)3, CuHf2(PO4)3, Li7La3Zr2O 12 , Li7La3Zr 2-x Nb x O 12, Li7La3Zr 2-x Ta x O 12 , Li5La3Ta2O 12 , Li 0.33 La 0.55 TiO3, Li 1.5 Al 0.5 Ge 1.5 P3O 12 , Li 1.3 Al 0.3 Ti 1.7 P3O 12 , Li3PO4 (LiPON), Li4SiO4-Li3PO4, Li4SiO4, or Li3BO3, etc., can be used as the solid electrolyte.

[0023] Molten salts can also be used as solid electrolytes or electrolyte solutions. When used in a relatively low-temperature environment, ionic liquids can also be used. Deep Eutectic Solvents (DES) can be used as ionic liquids.

[0024] As an example, a molten salt that can be used includes (a) at least one cation selected from the group consisting of imidazolium cation, pyridinium cation, piperidinium cation, pyrrolidinium cation, phosphonium cation, morpholinium cation, sulfonium cation, and ammonium cation, and (b) at least one anion selected from the group consisting of carboxylate anion, sulfonate anion, halogen anion, tetrafluoroborate, hexafluorophosphate, bis(trifluoromethanesulfonyl)imide, and bis(fluorosulfonyl)imide.

[0025] The electrolyte layer 4 may contain alkali metal ions as an additive. The alkali metal ions may be, for example, lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, or francium ions. Preferably, the alkali metal ions may be lithium ions, sodium ions, or potassium ions. By including alkali metal ions in the electrolyte layer 4, the life of the thermal power generation element 1 can be extended. Furthermore, the discharge characteristics can be restored by applying heat or vibration to the thermal power generation element 1 and leaving it. The alkali metal ions may be added to the electrolyte in the form of, but not limited to, halides, perchlorates (e.g., LiClO), sulfates, or strong acid salts. Various alkali metal compounds can be used as long as they are in a form that does not deteriorate the solvent.

[0026] The halogen that forms a halide with the alkali metal ion can be fluorine, chlorine, bromine, iodine, or astatine. For example, compounds of alkali metal ions with chlorine can include LiCl, NaCl, KCl, RbCl, CsCl, or FrCl. The amount of alkali metal compound added is not particularly limited, but by adding 0.001 to 100 parts by weight, preferably 0.01 to 10 parts by weight, and more preferably 0.03 to 0.1 parts by weight per 100 parts by weight of the electrolyte, the battery life of the thermal power generation element 1 can be extended.

[0027] The electrolyte layer 4 may contain components other than a solid electrolyte or an electrolyte solution. For example, the electrolyte layer 4 may contain a polar solvent (water, methanol, toluene, tetrahydrofuran, etc.) that dissolves or disperses the electrolyte, a binder (polyvinyl alcohol, methyl cellulose, acrylic resin, agar, etc.) that binds the electrolyte, and a sintering aid (magnesium oxide, yttrium oxide, calcium oxide, etc.) that helps form the hole transporting material.

[0028] [Material layer] The material layer 5 is a layer containing a thermoelectric conversion material capable of generating thermally excited electrons and holes by heat. Examples of the thermoelectric conversion material capable of generating thermally excited electrons and holes by heat include semiconductors. In this embodiment, the material layer 5 has a two-layer structure in which a semiconductor layer 51 containing a semiconductor and an electron transport layer 52 containing an electron transport material are stacked. In the material layer 5, one surface in the thickness direction of the electron transport layer 52 is in full or partial contact with the negative electrode 3. The other surface in the thickness direction of the electron transport layer 52 is in full or partial contact with one surface in the thickness direction of the semiconductor layer 51. The other surface in the thickness direction of the semiconductor layer 51 is in full or partial contact with the electrolyte layer 4.

[0029] The material layer 5 may have only the semiconductor layer 51 containing a semiconductor, i.e., a single layer structure. If the negative electrode 3 is a strip made of a conductive material, one end (part) of the strip is provided in contact with or connected to the material layer 5 (electron transport layer 52). Furthermore, as an example, a spacer material such as a protective layer may be interposed on at least a part of the surface of the material layer 5 (semiconductor layer 51) facing the electrolyte layer 4, so that the material layer 5 (semiconductor layer 51) and the electrolyte layer 4 are not in direct contact with each other.

[0030] The semiconductor constituting the semiconductor layer 51 is a thermally excited electron (e - Any material that can generate electrons (e) and holes (h) may be used. There are no particular limitations. As an example, the semiconductor included in the semiconductor layer 51 can be a metal semiconductor, a tellurium compound semiconductor, a silicon germanium (Si-Ge) compound semiconductor, a silicide compound semiconductor, a skutterudite compound semiconductor, a clathrate compound semiconductor, a Heusler compound semiconductor, a half-Heusler compound semiconductor, a metal oxide semiconductor, an organic semiconductor, a sulfide semiconductor, or any other semiconductor.

[0031] Examples of metal semiconductors include Si semiconductors and Ge semiconductors. Specific examples of tellurium compound semiconductors include Bi-Te compounds and related compounds (e.g., Bi2Te3, Sb2Te3, CsBi4Te6, Bi2Se3, Bi 0.4 Sb 1.6 Te3, Bi2(Se,Te)3, (Bi,Sb)2(Te,Se)3, (Bi,Sb)2Te3, Bi2Te 2.95 Se 0.05 etc.), Pb-Te compounds (e.g., PbTe, Pb 1-x Sn x Te).

[0032] Other tellurium compounds include SnTe, Ge-Te, AgSbTe2, Ag-Sb-Ge-Te compounds (e.g., GeTe-AgSbTe2 (TAGS)), Ga2Te3, (Ga 1-x In x )2Te3, Tl2Te-Ag2Te, Tl2Te-Cu2Te, Tl2Te-Sb2Te3, Tl2Te-Bi2Te3, Ti2Te-GeTe, Ag8Tl2Te5, Ag9TlTe5, Tl9BiTe6, Tl9SbTe6, Tl9CuTe5, Tl4SnTe3, Tl4PbTe3, Tl 0.02 Pb 0.98 Te etc.

[0033] Specific examples of silicon-germanium (Si-Ge) compound semiconductors include Si x Ge 1-x , or SiGe-GaP. Specific examples of silicide compound semiconductors include β-FeSi2 and its variants (e.g., Fe 1-x Mn x Si2, Fe 0.95 Mn 0.05 Si (2-y) Al y , FeSi (2-y) Al y , Fe 1-y Co y Si2), Mg2Si, MnSi 1.75-x , Ba8Si 46 , Ba8Ga 16 Si 30, or CrSi2, etc.

[0034] Specific examples of skutterudite compound semiconductors include: Compounds of formula TX3 (wherein T is a transition metal selected from Co, Fe, Ru, Os, Rh, and Ir, and X is a pnictogen selected from P, As, and Sb), derivatives of said compounds of formula RM4X 12 (wherein R is a rare earth element selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; M is a transition metal selected from Fe, Ru, Os, and Co; and X is a pnictogen selected from P, As, and Sb), y Fe 4-x Co x Sb 12 , (CeFe3CoSb 12 ) 1-x (MoO2) x , or (CeFe3CoSb 12 ) 1-x (WO2) x Examples include:

[0035] Specific examples of clathrate compound semiconductors include: formula M8X 46 (M is selected from Ca, Sr, Ba, Eu, and X is selected from Si, Ge, Sn), or a derivative thereof, represented by formula (II)8(III) 16 (IV) 30 (II is a group II element, III is a group III element, and IV is a group IV element) 16 (IV) 30 Examples of the compound include Ba8Ga x Ge 46-x , Ba 8-x (Sr,Eu) x Au6Ge 40 , or Ba 8-x EU x Cu6Si 40 Examples include:

[0036] Specific examples of Heusler compound semiconductors include Fe2VAl, (Fe 1-x Re x )2VAl, or Fe2(V 1-x-y Ti x Ta y )Al can be mentioned.

[0037] Specific examples of half-Heusler compound semiconductors include MSiSn (M is Ti, Zr, or Hf), MNiSn (M is Ti or Zr), MCoSb (M is Ti, Zr, or Hf), and LnPdX (Ln is selected from La, Gd, and Er, and X is Bi or Sb).

[0038] Metal oxide semiconductors include In2O3-SnO2, (CaBi)MnO3, Ca(Mn, In)O3, and Na x V2O5, V2O5, ZnMnGaO4 and its derivatives, LaRhO3, LaNiO3, SrTiO3, SrTiO3:Nb, Bi2Sr2Co2O y , Na x CoO2, NaCo2O4, CaPd3O4, formula Ca a M 1 b Co c M 2 d Ag e O f (M 1 is one or more elements selected from Na, K, Li, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Pb, Sr, Ba, Al, Bi, Y and rare earth elements, and M 2 is one or two elements selected from Ti, V, Cr, Mn, Fe, Ni, Cu, Mo, W, Nb, Ta, and Bi, and 2.2≦a≦3.6, 0≦b≦0.8, 2≦c≦4.5, 0≦d≦2, 0≦e≦0.8, and 8≦f≦10), ZnO, Na(Co,Cu)2O4, ZnAlO, Zn 1-x Al x O, or La 1.98 Sr 0.02 CuO4 can be mentioned.

[0039] The organic semiconductor may include an organic perovskite, a polyaniline, a polyacetylene, a polythiophene, a polyalkylthiophene, or a polypyrrole.

[0040] Examples of sulfide semiconductors include Ag2S, ZnS, and CdS.

[0041] Other thermoelectric compounds include alloys containing Co and Sb (e.g., CoSb3, CeFe3CoSb 12 , CeFe4CoSb 12 , or YbCo4Sb 12 ), alloys containing Zn and Sb (e.g., ZnSb, Zn3Sb2, or Zn4Sb3), alloys containing Bi and Sb (e.g., Bi 88 Sb 12 ), CeInCu2, (Cu,Ag)2Se, Gd2Se3, CeRhAs, or CeFe4Sb 12 , Li 7.9 B 105 , BaB6, SrB6, CaB6, AlPdRe compounds (e.g., Al 71 Pd 20 (Re 1-x Fe x )9), AlCuFe quasicrystal, Al 82.6-x Re 17.4 Si x 1 / 1 cubic approximation crystal, YbAl3, YbMn x Al3, β-CuAgSe, B4C / Ba3C, (Ce 1-x La x )Ni2, (Ce 1-x La x )In3 can be mentioned.

[0042] The electron transport material contained in the electron transport layer 52 is not particularly limited as long as its electron conduction band level (energy level of the electron conduction band) is the same as or positive to the electron conduction band level (energy level of the electron conduction band) of the thermoelectric conversion material in the material layer 5. When the electron conduction band levels of the thermoelectric conversion material and the electron transport material have been measured, a person skilled in the art can appropriately select an appropriate electron transport material for the thermoelectric conversion material in material layer 5 according to the values ​​of those levels (energy levels). Furthermore, for materials whose electron conduction band levels are unknown, the levels (energy levels) of the semiconductor and electron transport material can be measured by, for example, electrochemical measurement or inverse photoemission spectroscopy (IPES). Therefore, a person skilled in the art can appropriately select an appropriate electron transport material depending on the thermoelectric conversion material in material layer 5 used in the thermoelectric power generation element.

[0043] The electron transport material may be, for example, an N-type metal oxide containing at least one selected from the group consisting of niobium, titanium, zinc, tin, vanadium, indium, tungsten, tantalum, zirconium, molybdenum, and manganese, an N-type metal sulfide, an alkali metal halide, an alkali metal, or an electron-transporting organic compound.

[0044] More specifically, the electron transport material can be, for example, titanium oxide, tungsten oxide, zinc oxide, niobium oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, zinc sulfide, or SrTiO3. The electron transporting organic material may be, for example, an N-type conductive polymer, an N-type low molecular weight organic semiconductor, a π-electron conjugated compound, a carbon material, or a surfactant. Specific examples of the compound include oxadiazole derivatives, triazole derivatives, perylene derivatives, or quinolinol metal complexes, cyano group-containing polyphenylene vinylenes, boron-containing polymers, bathocuproine, bathophenanthrene, hydroxyquinolinatoaluminum, oxadiazole compounds, benzimidazole compounds, naphthalene tetracarboxylic acid compounds, phosphine oxide compounds, phosphine sulfide compounds, fluoro group-containing phthalocyanines, fullerenes and derivatives thereof, phenylene vinylene polymers, and perylene tetracarboxylic acid imide derivatives.

[0045] The difference in electron conduction band level between the electron transport material and the semiconductor is not limited, but is preferably 0.01 to 1 V, more preferably 0.01 to 0.5 V, even more preferably 0.01 to 0.3 V, and most preferably 0.05 to 0.2 V. For example, the difference between the electron conduction band level of β-FeSi2 and that of n-type silicon, that is, the level difference between the electron conduction band levels, is about 0.01V.

[0046] The mechanism of power generation in the thermal power generation element 1 will be described below. 1, in a cooling source 10 using a thermal power generation element 1, the thermal power generation element 1 is connected to a load R via a connection line L2 connected to a positive electrode 2 and a connection line L3 connected to a negative electrode 3. A switch SW is provided on the connection line L3. When the switch SW is turned on while heat is being applied to the thermal power generation element 1, the thermal power generation element 1 starts to generate power.

[0047] The thermal power generating element 1 (STC) of the present disclosure generates electricity by combining thermally excited electrons and holes in the semiconductor layer 51 with the oxidation-reduction reaction of the electrolyte. The thermoelectric conversion material (semiconductor, for example, germanium) contained in the semiconductor layer 51 is a substance that can generate a sufficient number of thermally excited electrons and holes for power generation at a certain temperature or higher. Therefore, when an appropriate temperature is applied to the thermoelectric conversion material, a sufficient number of thermally excited electrons and holes are generated to generate electricity.

[0048] The electron conduction band level of the electron transport material contained in the electron transport layer 52 is more positive (energy level) than the electron conduction band level of the thermoelectric conversion material contained in the semiconductor layer 51. Therefore, electrons generated in the semiconductor layer 51 move from the semiconductor layer 51 to the electron transport layer 52 and then move to the electrode (negative electrode 3). On the other hand, the redox level of the electrolyte contained in the electrolyte layer 4 is negative relative to the valence band position (valence band energy level) of the thermoelectric conversion material contained in the semiconductor layer 51. Therefore, holes are transported from the semiconductor layer 51 to the electrode (positive electrode 2).

[0049] That is, an oxidation-reduction reaction of ions occurs in the electrolyte, electrons are transported from the electrode (positive electrode 2) to the semiconductor layer 51, and holes are transported from the semiconductor layer 51 to the electrode (positive electrode 2). Through this mechanism, electrons move from the negative electrode 3 to the positive electrode 2, and electricity can be generated. In the cooling source 10, when the switch SW is turned on, electrons move from the negative electrode 3 to the positive electrode 2 via the load R, generating a current that flows within the circuit of the cooling source 10. In the embodiment, a semiconductor-sensitized thermoelectric power generating element is fabricated by combining a thermoelectric conversion material, an electron transport material, and an electrolyte that satisfy these conditions.

[0050] [Power generation temperature] As an example, the thermal energy generation element 1 is a thermoelectric conversion material that generates thermally excited electrons and holes, and the thermally excited electron density is 10 10 / m 3 Power is generated in an environment where the temperature is above this limit. The thermally excited electron density is 10 10 / m 3 It is sufficient if it is more than 10 15 / m 3 More preferably, 10 18 / m 3 More preferably, 10 20 / m 3 or more, and most preferably 10 22 / m 3 The higher the thermally excited electron density, the higher the power generation efficiency that can be obtained. Therefore, although the thermally excited electron density differs depending on the thermoelectric conversion material, the temperature at which the thermal energy generation element 1 starts to generate power is when the thermally excited electron density is 10 10 / m 3 The temperature is preferably 10 15 / m 3It is more preferably 10 18 / m 3 More preferably, it is a temperature at which 20 / m 3 The temperature is preferably 10 22 / m 3 This is the temperature at which the temperature is equal to or higher than this.

[0051] The power generation temperature of the present disclosure is preferably a temperature at which charge-transporting ion pairs can move back and forth within the electrolyte. The specific temperature is not limited, but is, for example, 0°C or higher, preferably 30°C or higher, more preferably 40°C or higher, more preferably 60°C or higher, and even more preferably 80°C or higher. The upper limit of the temperature is not particularly limited as long as it is a temperature at which the charge-transporting ion pair can move back and forth within the electrolyte, but is, for example, 1500°C or lower, and preferably 1000°C or lower.

[0052] The temperature at which a heat-utilizing power generation element (thermoelectric power generation element) actually generates power (power generation temperature) is the temperature at which a sufficient number of thermally excited electrons and holes for power generation are generated in the thermoelectric conversion material in the semiconductor layer 51. Furthermore, the power generation temperature also depends on the ease of electron movement inherent to the material. It is also affected by the ease of electron movement at the interface between the electrolyte layer 4 and / or the electron transport layer 52 and the semiconductor layer 51. These conditions can be considered as appropriate.

[0053] Charge-transporting ion pairs that shuttle through an electrolyte are two stable ions with different valences (see Figure 1). Charge-transporting ion pairs can also be ions of the same element with different valences. The valence band level of the thermoelectric conversion material (semiconductor) contained in the semiconductor layer 51 is more positive than the redox level of the charge-transporting ion pair in the electrolyte layer 4. Therefore, at the interface between the semiconductor layer 51 and the electrolyte layer 4, the ion that is more easily oxidized of the two ions (Ox / Red) is oxidized to become the other ion. As a result, electrons (e - ) and holes (h) are transported. Furthermore, at the interface between the positive electrode 2 and the electrolyte layer 4, the ion that is more easily reduced of the two ions undergoes a reduction reaction.

[0054] For example, in the case of copper ions, monovalent copper ions and divalent copper ions are preferred. In the case of iron ions, divalent iron ions and trivalent iron ions are preferred. Specific examples of monovalent copper ions include CuCl, CuBr, copper(I) acetate, copper(I) iodide, and copper(I) sulfate. Specific examples of divalent copper ions include CuCl2, CuTSFI2, copper(II) acetate, copper(II) sulfate, or copper(II) acetylacetonate. Specific examples of divalent iron ions include Fe(C5H5)2 (ferrocene), K4[Fe(CN)6], iron(II) acetylacetonate, iron(II) chloride, iron(II) sulfate, or iron(II) acetate. Specific examples of ferric ions include FeCl3, K3[Fe(CN)6], iron(III) acetylacetonate, or iron(III) sulfate.

[0055] By applying heat to the thermal power generation element 1, the following (i) to (vi) occur. (i) The electrons (e - ) is given energy by the addition of heat (=thermal excitation). (ii) Thermally excited electrons (e - ) migrates to the more stable electron transport layer 52. (iii) When the electrodes (positive electrode 2, negative electrode 3) are connected to a load R, electrons (e - ) travels through the negative electrode 3 in contact with the material layer 5, the connection line L3, the load R, and the connection line L2, and then travels to the positive electrode 2 side, which is the opposite electrode. (iv) Electrons transferred to the positive electrode 2 (e - ) is the oxide ions (Cu) of the electrolyte contained in the electrolyte layer 4 on the electrode surface in contact with the electrolyte layer 4. 2+ (Ox)) to reduce ions (Cu + (Red)). (v) The holes (h) in the semiconductor of the semiconductor layer 51 are converted into reduced ions (Cu + (Red)) to oxide ions (Cu 2+ (Ox)). (vi) The oxidized and reduced ions in the electrolyte layer 4 move within the electrolyte. This causes electrons (e - ) and holes (h) are transported.

[0056] Figure 2 is a diagram illustrating the distribution of ions in the electrolyte of the electrolyte layer 4. Figure 2(a) schematically illustrates a state in which the distribution of ions in the electrolyte is uniform and the thermal power generation element 1 is capable of discharging. Figure 2(b) schematically illustrates a state in which the distribution of ions in the electrolyte is non-uniform and the discharging of the thermal power generation element 1 has stopped. Fig. 3 is a schematic diagram showing an example of the waveform of the output voltage of the thermal power generation element 1. Fig. 3 shows the change in output voltage when the switch SW is repeatedly opened and closed in accordance with the characteristics of the thermal power generation element 1.

[0057] The thermal power generation element 1 generates electricity by converting thermal energy into electrical energy through a combination of thermally excited charges in a semiconductor and an oxidation-reduction reaction in an electrolyte. As the oxidation-reduction reaction is repeated in the thermal power generating element 1, the Fermi level of the semiconductor layer 51 and the oxidation-reduction level of the electrolyte in the electrolyte layer 4 reach a chemical equilibrium state, which causes the discharge of the thermal power generating element 1 to end.

[0058] In this state, there is a bias in the distribution of ions in the electrolyte of the electrolyte layer 4. As shown in FIG. 2(b), when the discharge is completed, the oxide ions (Cu 2+ The concentration of reduced ions (Cu (Ox)) decreases from the material layer 5 toward the positive electrode 2. + The concentration of oxidized ions (Cu (Red)) decreases from the positive electrode 2 toward the material layer 5. 2+ (Ox)) is the highest, while the concentration of reduced ions (Cu +(Red)) has the highest concentration.

[0059] After the discharge of the thermal power generation element 1 is completed, if the switch SW is opened while heat is still being applied to the thermal power generation element 1 to disconnect the thermal power generation element 1 from the load R, the thermally excited electrons in the semiconductor layer 51 will have nowhere to go, and as a result, the equilibrium state of the electrolyte in the electrolyte layer 4 will change. Specifically, the ions in the electrolyte of the electrolyte layer 4 diffuse to eliminate the uneven distribution. As a result, the oxide ions (Cu 2+ (Ox)) and the concentration of reduced ions (Cu + The bias in the concentration of red (red) gradually disappears, and the thermal power generation element 1 returns to its initial state (see (a) in Figure 2) where discharge is possible. As shown in Figure 3, after the switch SW is turned off, the voltage that the thermal power generation element 1 can output recovers (Figure 3: voltage recovery).

[0060] When the ions in the electrolyte have diffused and the imbalance in ion distribution has been eliminated (see (a) in Figure 2), the switch SW is closed and the thermal power generation element 1 is connected to the load R, and the thermal power generation element 1 begins discharging again (Figure 3: Discharge).

[0061] In this way, the thermal power generation element 1 stops generating electricity when it continues discharging and reaches a chemical equilibrium state (see (b) in Figure 2). Even after power generation ends, it can be restored to a state where it can generate electricity again (see (a) in Figure 2) by transitioning to a state where no power is extracted.

[0062] A large open circuit voltage (OCV) is generated when heat is applied to the thermal power generation element 1. As shown in Figure 3, when the switch SW is closed (ON), the thermal power generation element 1 starts discharging. For example, if the load R is a battery, the power of the heat-utilizing power generation element 1 is supplied to the battery, and the battery is charged.

[0063] The voltage of the thermal power generation element 1 drops quickly due to discharge, then gradually decays and drops to a voltage value that indicates the end of discharge. If the switch SW is opened (OFF) at this timing, the thermal power generation element 1 is disconnected from the load R, and the voltage of the thermal power generation element 1 recovers. Then, when the imbalance in the distribution of ions in the thermal power generation element 1 is resolved (recovered) to the point where discharge is possible (see (a) of Figure 2), the switch SW is closed (ON) again, and the thermal power generation element 1 begins discharging again.

[0064] In this embodiment, by opening and closing the switch SW, the cooling source 10 using the thermal power generation element 1 automatically repeats a power generation cycle consisting of a discharge phase (cooling phase) and a voltage recovery phase (non-cooling phase). The thermal power generation element 1 generates power by converting thermal energy into electrical energy, regardless of the temperature gradient in the installation environment. During this process, heat absorption occurs as the power is generated, cooling the area around the thermal power generation element 1.

[0065] Here, if the cooling source 10 is equipped with a plurality of thermal power generation elements 1, by sequentially switching the thermal power generation elements 1 that are performing the discharging phase (cooling phase), it is possible to continuously perform cooling associated with the power generation of the thermal power generation elements 1. Note that if at least two thermal power generation elements 1 are provided, the period during which cooling associated with the power generation of the thermal power generation elements 1 can be extended by alternately switching the thermal power generation element 1 that performs discharging.

[0066] FIG. 4 is a schematic diagram illustrating a cooling device 100 that employs the cooling source 10. As shown in FIG. In the cooling device 100, a plurality of switches SW are provided on a substrate 61 that is equipped with an MPU (controller 62) that performs arithmetic processing. One side of each switch SW is connected to a first port P1, and the other side is connected to the electrode (negative electrode) of the corresponding reference cell 30. The electrode (positive electrode) of each reference cell 30 is commonly connected to a second port P2 on the substrate 61.

[0067] The reference cell 30 has a basic configuration in which a thermal power generation element 1 is housed in an insulating container 20 made of a material with high thermal conductivity. The thermal power generation element 1 has a basic configuration (see Figure 1) in which a material layer 5 (first layer) containing a thermoelectric conversion material and an electrolyte layer 4 (second layer) containing an electrolyte are stacked between a first electrode sheet, a positive electrode 2, and a second electrode sheet, a negative electrode 3. As an example, the material layer 5 contains a semiconductor, and the thermal power generation element 1 is a semiconductor-sensitized thermal power generation element (STC) that generates electricity by utilizing an oxidation-reduction reaction caused by thermally excited charges in the semiconductor. It should be noted that a plurality of thermal power generation elements 1 (cooling sources 10) may be housed in each of the reference cells 30. The layer structure of the thermal power generation element 1 is not limited to that shown in FIG.

[0068] In the cooling device 100, a plurality of reference cells 30 are stacked, and the negative electrode of each reference cell 30 is individually connected to the switch SW. The on / off of the switches SW is controlled by a control unit 62 on a substrate 61. In this embodiment, the plurality of reference cells 30 are divided into a predetermined number of groups GW (GW1, GW2, ...), and the on / off of the switches SW corresponding to each group is collectively controlled by the control unit 62.

[0069] When using the cooling device 100, the cooling device 100 is installed near a heat source, and then the first port P1 and the second port P2 are connected to a load. The control unit 62 turns on the switch SW corresponding to the group to which the reference cell 30 that generates power belongs (hereinafter referred to as the "power generation group"), putting the reference cell 30 in the power generation group into a power generation state. For other groups that do not generate power (hereinafter referred to as the "non-power generation group"), the control unit 62 turns off the switch SW, putting the reference cell 30 in the non-power generation group into a recovery state (voltage recovery and rebalancing of ion distribution). The control unit 62 switches the power generation group based on a predetermined condition (for example, a voltage threshold or a timer). For example, if GW1 in Fig. 4 is a power generation group and the other groups GW2 and GW3 are non-power generation groups, the control unit 62 sets the group GW2 as a new power generation group and sets the groups GW1 and GW3 as non-power generation groups. As a result, the reference cells 30 in the group GW2 enter a power generating state, the reference cells 30 in the group GW1 enter a recovery state, and the reference cells 30 in the group GW3 remain in the recovery state. Thereafter, the control unit 62 sets the group GW3 as a new power generation group and sets the groups GW1 and GW2 as non-power generation groups based on a predetermined condition.

[0070] In this way, the control unit 62 switches the power generation group including the reference cell 30 to be put into a power generating state between the groups GW1 to GW3 in order. This ensures a continuous heat absorption effect of the reference cell 30 during power generation, and allows the cooling of the heat utilization power generation element 1 due to power generation to continue uninterrupted.

[0071] In the embodiment, the reference cells 30 that are put into a power generating state are switched in sequence to ensure that power is generated in any one of the heat power generation elements 1, thereby continuously and uninterruptedly cooling the cells 30. Alternatively, the reference cells 30 that are put into a power generating state may be switched in sequence to intermittently generate power, thereby intermittently cooling the cells 30.

[0072] In the above-described embodiment, it is described that the generated power is supplied to the load. For example, if a battery capable of storing power is used as the load, the cooling device 100 can perform cooling and charging of the battery. Furthermore, if the load is an intermittently driven sensor (e.g., a temperature sensor), the temperature sensor can be driven with the power generated by the cooling device 100. This eliminates the need to provide a separate power supply line or power source for driving the temperature sensor, thereby reducing the possibility that the overall device configuration of the cooling device 100, including the temperature sensor, will become large.

[0073] [Confirmation test] FIG. 5 is a schematic diagram of a test device when a confirmation test is performed using the test cell C. FIG. 6 is a graph summarizing the relationship between the load conditions and the temperature difference ΔT when a confirmation test was carried out using the test cell C shown in FIG.

[0074] Test cell C was fabricated by arranging a sheet-shaped semiconductor-sensitized heat-utilizing power generation element 1A with a four-layer structure (positive electrode, negative electrode, material layer containing thermoelectric conversion material, and electrolyte layer) and an element 1B that does not contain ions in the electrolyte layer, facing each other via a heat insulator 7. By placing the heat insulator between 1A and 1B, direct heat transfer between the two elements was suppressed. Here, "containing no ions in the electrolyte layer" means that there is no movement of the two ions of the charge-transporting ion pair.

[0075] The fabricated test cell C was placed in a test container 8, and the test container 8 was immersed in a water bath 9 filled with boiling water to heat the air inside the test container 8. In this state, one of the heat-utilization power generation elements 1A was connected to a load R to generate electricity, while the other element 1B, which did not contain ions in its electrolyte layer, was used as a reference and was not connected to the load R (and did not generate electricity). The temperature difference ΔT between them (=temperature of the thermal power generation element 1A - temperature of the element 1B which does not contain ions in the electrolyte layer) was evaluated.

[0076] A thermocouple sensor was used for temperature measurement. The temperature of the thermal power generation element 1A was obtained under conditions where the temperature of the reference element 1B, which does not contain ions in the electrolyte layer, was in the range of 30.0 to 80.0°C, and the above ΔT was calculated. The load conditions were switched between an open circuit and a resistive load (e.g., R = 100Ω, 1 kΩ, 6.8 kΩ). As a result, ΔT was smallest when the temperature of the thermal power generation element 1A was around 50 to 60°C, and a maximum cooling of approximately -5°C was obtained when the load was connected. On the other hand, the amount of cooling was small in the reference, and it was confirmed that there was a significant heat absorption effect during power generation.

[0077] In the above-described embodiment, a sheet-like thermal power generation element 1 is used in which an electrolyte layer 4 in which charge-transporting ion pairs are mobile and a material layer 5 containing a thermoelectric conversion material are sandwiched between sheet-like electrodes (a positive electrode 2 and a negative electrode 3). The thermal power generation element 1 is not limited to this embodiment. For example, the thermal power generation element may be one that employs comb-shaped electrodes in which positive electrodes 2 and negative electrodes 3 are printed on a substrate and alternately arranged at intervals.

[0078] The above embodiment has been described as an example of a semiconductor sensitized thermoelectric generator 1 (STC) that is not dependent on the temperature gradient of the installation environment. The thermoelectric generation technologies shown in Table 1 below may also be used. [Table 1]

[0079] [Graded band gap] Thermoelectric power generation using a graded bandgap employs an element with a gradient connection from a semiconductor with a narrow bandgap to a semiconductor with a wide bandgap, and is characterized by generating a flow of charge by utilizing the difference in the amount of thermally excited charge generated due to the size of the bandgap. A thermal power generation element using this graded band gap can be used as the thermal power generation element of the present invention.

[0080] [Thermally Activated Delayed Fluorescence (TADF)] This device is characterized by using an organic light-emitting material in which thermally excited charges do not easily recombine, and by separating the thermally excited charges using an electron transport layer and a hole transport layer, generating a current and thus generating electricity. This thermally excited delayed fluorescence element can be used as the heat-utilizing power generation element of the present invention.

[0081] [TPV (Thermophotovoltaics)] When light is incident on a photovoltaic (PV) cell, light with energy corresponding to the band gap of the PV cell is absorbed and converted into electricity. Instead of sunlight, a thermophotovoltaic power generation element (solar cell) that uses thermal radiation from a heated object (high-temperature emitter) as incident light can be used as a thermal power generation element. The thermal radiation of a high-temperature emitter changes its spectrum and radiant flux depending on the temperature. By using a heated emitter and a selective emitter / filter to shape the radiation and couple it to a nearby PV cell (solar cell), an electromotive force is generated, and electricity derived from the thermal radiation can be extracted.

[0082] [Molecular Piezoelectricity] The technology is characterized by generating electricity by utilizing the fact that the movement of liquid molecules increases at high temperatures, and these molecules collide with piezoelectric materials, generating pressure. This molecular pressure power generation element can be used as the heat-utilizing power generation element of the present invention.

[0083] [Metamaterial Thermoelectrics] By attaching a metamaterial that easily absorbs specific wavelengths to one side of a Seebeck-type thermoelectric material, the artificial nanostructure increases phonon scattering while maintaining electron transport, improving the balance between effective thermal conductivity and the Seebeck coefficient (ZT). When the Seebeck voltage generated under a temperature gradient is coupled to an external circuit, a potential difference is generated, allowing high-output electricity to be extracted even at the same temperature T. This power generation element utilizing metamaterial thermoelectric conversion can be used as the heat-utilizing power generation element of the present application.

[0084] [Using temperature changes over time] The redox equilibrium at the electrode-electrolyte interface shifts with temperature, resulting in a temperature coefficient of electromotive force derived from the reaction entropy. Based on this, the chemical potential difference caused by the temperature change of the entire cell is stored in a circuit, allowing electricity to be extracted directly from heat. This power generation element used for generating electricity by utilizing the temperature change of the entire cell can be used as the heat-utilizing power generation element of the present invention.

[0085] [Nanoparticle hopping] The technology is characterized by the fact that a solution containing dispersed nanoparticles is placed between electrode materials with different work functions, and the property of electrons moving to the electrode with the larger work function is utilized to generate a flow of electrons and generate electricity. This technology works by causing a potential difference between electrodes, which is caused by a difference in work function, to cause electrons to hop from one electrode to the other via nanoparticles, resulting in the transfer of charge between the electrodes and the generation of an electric current. A power generating element used for generating electricity using this hopping conduction can be used as the heat-utilizing power generating element of the present invention.

[0086] [Graphene-based Energy Conversion] Because graphene is light and thin, the film vibrates in response to thermal fluctuations (ripples / Brownian motion) at room temperature. When the non-equilibrium component originating from these fluctuations, which is maintained by heating and cooling, is coupled to a rectifier circuit such as an asymmetric electrode or diode, an average potential difference is generated, which can be extracted as a minute DC power. A power generation element that uses this graphene for power generation can be used as the heat-utilizing power generation element of the present application.

[0087] As described above, the cooling source 10 according to this embodiment has the following configuration. (1) The cooling source 10 uses a thermal power generation element 1 that is not dependent on the temperature gradient of the installation environment.

[0088] The thermal power generation element 1 absorbs heat when generating electricity using heat. Therefore, if a cooling source 10 using the thermal power generation element 1 is installed near a heat source that needs to be cooled, it is possible to suppress heating of the heat source while generating electricity using the heat of the heat source. This makes it possible to suppress heating of the heat source while effectively utilizing the exhaust heat of the heat source. For example, if the cooling source 10 is attached to a board on which a CPU, which is a processing unit, is mounted, the heat generated by the CPU during processing can be used by the thermal power generation element 1 to cool the CPU while generating power. This prevents the CPU from overheating, and the heat from the CPU can be used to generate electricity, which can be used to power devices mounted on the board or to charge batteries connected to the board.

[0089] (2) In (1) above, The thermal power generation element 1 is The basic structure is such that a material layer 5 (first layer) containing a thermoelectric conversion material and an electrolyte layer 4 (second layer) containing an electrolyte are stacked between a positive electrode 2, which is a first electrode sheet, and a negative electrode 3, which is a second electrode sheet.

[0090] The thermal power generation element 1 has a basic structure consisting of four layers, and by connecting the connection wire L2 connected to the positive electrode 2 and the connection wire L3 connected to the negative electrode 3 to the load R, it is possible to generate and absorb heat stably. In particular, unlike Seebeck-type thermoelectric generators, the thermal power generation element 1 can generate electricity using heat without requiring a temperature gradient in the installation environment. Therefore, since no mechanism for generating a temperature gradient is required, the thermal power generation element 1 can be made smaller. This makes it possible to provide a compact thermal power generating element 1 that reliably functions as a cooling source.

[0091] (3) In (1) or (2) above, The thermal power generation element 1 can be cooled as the element 1 generates power.

[0092] This allows the thermal power generation element 1 to generate power using the exhaust heat from the heat source and perform cooling associated with the power generation in parallel. For example, if the thermal power generation element 1 is attached to an MPU (controller 62) installed on a substrate 61 (see FIG. 4), heat generated during arithmetic processing in the controller 62 can be used to generate power to drive the controller 62, while also cooling the controller 62.

[0093] (4) In any one of (1) to (3) above, The cooling source 10 has at least two thermal power generation elements 1. The cooling source 10 switches the heat utilization power generation element 1 that generates power, and cooling associated with power generation is carried out continuously or intermittently.

[0094] If the total number of thermal power generation elements 1 is large and power generation can always be performed by at least one thermal power generation element 1, interruption of the cooling effect due to power generation stoppage can be prevented by switching the thermal power generation element 1. In this case, power generation using the waste heat of the heat source can be continued while the heat source and the surrounding space can be continuously cooled for a long period of time. In addition, if the total number of thermal power generation elements 1 is small and it is not possible to generate power in at least one thermal power generation element 1 at all times, intermittent power generation and cooling can be performed continuously by switching the thermal power generation element 1 that is generating power. This allows for continuous intermittent power generation using the waste heat from the heat source. By installing the thermal power generation element 1 in a container that limits heat exchange with the outside, the inside of the container can be cooled stably even when cooling occurs intermittently.

[0095] (5) In any one of (1) to (4) above, The thermal power generating element 1 is a semiconductor-sensitized thermal power generating element that generates electricity by utilizing an oxidation-reduction reaction caused by thermally excited charges in a semiconductor.

[0096] By using semiconductor-sensitized thermal power generation elements 1, once a predetermined time has passed since power generation was stopped, the semiconductor-sensitized thermal power generation elements 1 will return to a state where they can generate power again. Therefore, by determining the total number of thermal power generation elements 1 taking into consideration the time it will take to return to a state where they can generate power, it is possible to continuously cool the heat source. Furthermore, efficient power generation is possible using oxidation-reduction reactions caused by thermally excited charges, so that stable power generation and heat absorption can be achieved even with waste heat in the low temperature range, thereby improving the effectiveness of the cooling source 10.

[0097] (6) In any one of (1) to (4) above, The thermal power generation element 1 is any one of a thermal power generation element for generating electricity using a graded band gap, a thermal power generation element for generating electricity using thermally excited delayed fluorescence, a thermal power generation element for thermophotovoltaic power generation, a thermal power generation element for molecular piezoelectric power generation, a thermal power generation element for generating electricity using metamaterial thermoelectric conversion, a thermal power generation element for generating electricity using temperature changes over time, a thermal power generation element for generating electricity using nanoparticle hopping, and a thermal power generation element for generating electricity using graphene.

[0098] Since a variety of types of thermal power generation elements can be used, the optimum power generation element for the cooling source 10 can be selected depending on the conditions and environment of the heat source. Each method allows power generation without the need for a temperature gradient in the installation environment, and also allows for efficient cooling by utilizing the heat absorption effect during power generation.

[0099] The present disclosure may also be identified as a cooling device 100 . (7) The cooling device 100 is a material layer 5 (first layer) to which a negative electrode 3 (first electrode) is connected and which contains a thermoelectric conversion material; a thermal power generation element 1 having a basic structure in which a positive electrode 2 (second electrode) is connected to the thermal power generation element 1 and an electrolyte layer 4 (second layer) containing an electrolyte are stacked; a reference cell 30 in which the thermal power generation element 1 is housed in a container 20 made of a material with high thermal conductivity; and a control unit 62 (control device) that controls the power generation of the heat-utilizing power generation element 1 housed in the reference cell 30. The cooling device 100 includes a plurality of reference cells 30 . The control unit 62 sequentially switches the reference cells 30 that house the heat power generation elements 1 to be power-generated, and performs cooling of the heat power generation elements 1 by power generation continuously or intermittently.

[0100] By using the reference cell 30 in which the thermal power generation element 1 is housed in a container 20 with high thermal conductivity, heat transfer from the heat source to the thermal power generation element 1 can be made more efficient. If the total number of reference cells 30 is large and power generation can always be performed in at least one reference cell 30's thermal power generation element 1, interruption of the cooling effect due to power generation halts can be prevented by switching the reference cell 30 that is generating power. In this case, power generation using the waste heat of the heat source can be continued, while the heat source and the surrounding space can be continuously cooled for a long period of time. Furthermore, if the total number of reference cells 30 is small and power generation cannot always be performed in at least one reference cell 30's heat-utilizing power generation element 1, intermittent power generation and cooling can be continued by switching the reference cell 30 that is generating power. By individually controlling the power generation of the heat-utilizing power generating element 1 of each reference cell 30, the cooling effect can be exerted continuously or intermittently.

[0101] (8) In (7) above, The plurality of reference cells 30 are arranged in a plurality of groups GW. The control unit 62 controls each group to generate power, and switches between groups to continuously or intermittently cool the heat power generation elements 1 by generating power.

[0102] By grouping the thermal power generation elements and generating power in groups, it is possible to efficiently control a large number of thermal power generation elements, resulting in higher power generation capacity and higher cooling capacity. Switching between groups improves the continuity of cooling, allowing heat sources to be cooled stably for long periods of time.

[0103] (9) In (7) or (8) above, The thermal power generation element 1 is The semiconductor-sensitized thermal power generation element 1 generates electricity by utilizing an oxidation-reduction reaction caused by thermally excited charges in a semiconductor.

[0104] By incorporating the semiconductor-sensitized thermal power generation element 1 into the cooling device 100, the entire device can perform both power generation and cooling even in low temperature ranges. As a cooling device 100 that actively utilizes the waste heat from the heat source, it is possible to operate with high efficiency and energy conservation.

[0105] (10) In (7) or (8) above, The thermal power generation element 1 is any one of a thermal power generation element for generating electricity using a graded band gap, a thermal power generation element for generating electricity using thermally excited delayed fluorescence, a thermal power generation element for thermophotovoltaic power generation, a thermal power generation element for molecular piezoelectric power generation, a thermal power generation element for generating electricity using metamaterial thermoelectric conversion, a thermal power generation element for generating electricity using temperature changes over time, a thermal power generation element for generating electricity using nanoparticle hopping, and a thermal power generation element for generating electricity using graphene.

[0106] Since various types of thermal power generation elements can be used, the optimum power generation element can be selected as the cooling source 10 of the cooling device 100 depending on the conditions and environment of the heat source. Each method allows power generation without the need for a temperature gradient in the installation environment, and also allows for efficient cooling by utilizing the heat absorption effect during power generation.

[0107] The semiconductor-sensitized thermal power generation element 1 (STC) according to the present disclosure can generate electricity and perform cooling by being placed in a constant temperature environment, without requiring a temperature gradient in the installation environment. Therefore, the thermal power generation element 1 (STC) can generate electricity by utilizing heat from various heat sources such as geothermal energy, solar heat, waste heat from factories and data centers, body heat, room temperature of the installation environment, etc. Furthermore, the heat absorbed when generating electricity by the thermal power generation element 1 can cool the surrounding area. Furthermore, if the load connected to the cooling device 100 is a battery device, the power generated by utilizing the heat of the heat source can be stored in the battery. The power stored in the battery can also be used to drive various devices as needed. Furthermore, by incorporating the sensor that monitors the temperature of the heat source, etc., it is possible to continue monitoring the temperature of the heat source by installing it near the heat source even in an environment where it cannot be connected to a power source. Furthermore, the semiconductor sensitized thermal power generation element 1 is not limited to being installed on a fixed heat source. For example, the thermal power generation element 1 can also be installed in a heat flow of a liquid or gas to generate power. Furthermore, since the semiconductor sensitized thermal power generation element 1 does not require a cooling device, it is easy to miniaturize the thermal power generation element 1, the cooling source 10 that uses the thermal power generation element, and the cooling device 100.

[0108] The present invention is not limited to the above-described embodiment and modified examples, and can be modified as appropriate within the scope of the technical concept of the present invention. Furthermore, the modified examples may not only be applied to the embodiment, but at least a portion of the content of each modified example may also be applied to other modified examples. [Explanation of symbols]

[0109] 1, 1A: Thermal power generation element 10: Cooling source 100: Cooling device 2: Positive electrode (electrode sheet) 3: Negative electrode (electrode sheet) 4: Electrolyte layer 5: Material layer 51: Semiconductor layer 52: Electron transport layer 8: Test container 9: Water bath 20: Container 30: Reference cell 61: Circuit board 62: Control unit

Claims

1. A cooling source using a thermal power generation element that does not depend on a temperature gradient, The thermal power generation element is A cooling source having a basic configuration in which a first layer containing a thermoelectric conversion material and a second layer containing an electrolyte are stacked between a first electrode sheet and a second electrode sheet.

2. 10. The cooling source of claim 1, A cooling source capable of cooling the thermal power generation element in conjunction with power generation.

3. 10. The cooling source of claim 1, The thermal power generation element includes at least two of the thermal power generation elements, A cooling source in which cooling accompanying power generation is carried out continuously or intermittently by switching the heat utilization power generation element that generates power.

4. The cooling source according to any one of claims 1 to 3, The thermal power generation element is A cooling source is a semiconductor-sensitized thermal power generation element that generates electricity by utilizing the oxidation-reduction reaction caused by thermally excited charges in semiconductors.

5. The cooling source according to any one of claims 1 to 3, The thermal power generation element is any one of a thermal power generation element for thermophotovoltaic power generation, a thermal power generation element for molecular piezoelectric power generation, a thermal power generation element for power generation using temperature changes over time, a thermal power generation element for power generation using nanoparticle hopping, and a thermal power generation element for power generation used in power generation using graphene.

6. A cooling source using a thermal power generation element that is not dependent on a temperature gradient, The thermal power generation element is A cooling source is a semiconductor-sensitized thermal power generation element that generates electricity by utilizing the oxidation-reduction reaction caused by thermally excited charges in semiconductors.

7. A cooling source using a thermal power generation element that is not dependent on a temperature gradient, The thermal power generation element is any one of a thermal power generation element for thermophotovoltaic power generation, a thermal power generation element for molecular piezoelectric power generation, a thermal power generation element for power generation using temperature changes over time, a thermal power generation element for power generation using nanoparticle hopping, and a thermal power generation element for power generation used in power generation using graphene.

8. a thermal power generation element having a basic structure in which a first layer connected to a first electrode and containing a thermoelectric conversion material and a second layer connected to a second electrode and containing an electrolyte are stacked; a reference cell in which the thermal power generation element is housed in a container made of a material with high thermal conductivity; a control device that controls the power generation of the thermal power generation element, a plurality of the reference cells; The control device is a cooling device in which the control device sequentially switches between reference cells that house the heat-utilizing power generation elements to generate power, and continuously or intermittently performs cooling by power generation of the heat-utilizing power generation elements.

9. 9. The cooling device according to claim 8, the plurality of reference cells are arranged in a plurality of groups; The control device causes each group to generate power, and by switching between the groups, the cooling device performs cooling by power generation of the thermal power generation elements continuously or intermittently.

10. The cooling device according to claim 8 or claim 9, The thermal power generation element is A cooling device that is a semiconductor-sensitized thermal power generation element that generates electricity by utilizing the oxidation-reduction reaction caused by thermally excited charges in semiconductors.

11. The cooling device according to claim 8 or claim 9, The cooling device, wherein the thermal power generation element is any one of a thermal power generation element for thermophotovoltaic power generation, a thermal power generation element for molecular piezoelectric power generation, a thermal power generation element for power generation using temperature changes over time, a thermal power generation element for power generation using nanoparticle hopping, and a thermal power generation element for power generation using graphene.

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