WO2022259759A1 - 熱電変換素子、熱電変換モジュール、及び、熱電変換素子の製造方法 - Google Patents
熱電変換素子、熱電変換モジュール、及び、熱電変換素子の製造方法 Download PDFInfo
- Publication number
- WO2022259759A1 WO2022259759A1 PCT/JP2022/017564 JP2022017564W WO2022259759A1 WO 2022259759 A1 WO2022259759 A1 WO 2022259759A1 JP 2022017564 W JP2022017564 W JP 2022017564W WO 2022259759 A1 WO2022259759 A1 WO 2022259759A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- thermoelectric conversion
- conversion element
- layer
- metal layer
- bonding layer
- Prior art date
Links
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 322
- 238000004519 manufacturing process Methods 0.000 title claims description 29
- 239000000463 material Substances 0.000 claims abstract description 169
- 229910052751 metal Inorganic materials 0.000 claims abstract description 80
- 239000002184 metal Substances 0.000 claims abstract description 80
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 65
- 239000000956 alloy Substances 0.000 claims abstract description 65
- 229910052797 bismuth Inorganic materials 0.000 claims abstract description 58
- 229910052787 antimony Inorganic materials 0.000 claims abstract description 54
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 49
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 42
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 36
- 239000000203 mixture Substances 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 6
- 238000003825 pressing Methods 0.000 claims description 6
- 238000001237 Raman spectrum Methods 0.000 claims description 4
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 3
- 238000011049 filling Methods 0.000 claims description 3
- 238000000465 moulding Methods 0.000 claims description 2
- 229910052709 silver Inorganic materials 0.000 claims description 2
- 239000012071 phase Substances 0.000 description 30
- 238000005245 sintering Methods 0.000 description 28
- 239000000843 powder Substances 0.000 description 21
- 229910000789 Aluminium-silicon alloy Inorganic materials 0.000 description 14
- 239000013078 crystal Substances 0.000 description 12
- 238000010586 diagram Methods 0.000 description 12
- 238000005304 joining Methods 0.000 description 9
- 238000012360 testing method Methods 0.000 description 9
- 238000002490 spark plasma sintering Methods 0.000 description 8
- 238000000354 decomposition reaction Methods 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 6
- 238000001069 Raman spectroscopy Methods 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 238000002441 X-ray diffraction Methods 0.000 description 5
- 239000012298 atmosphere Substances 0.000 description 5
- 239000012535 impurity Substances 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 238000003746 solid phase reaction Methods 0.000 description 5
- 229910021389 graphene Inorganic materials 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 3
- 239000012300 argon atmosphere Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 238000005551 mechanical alloying Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 229910018125 Al-Si Inorganic materials 0.000 description 2
- 229910018520 Al—Si Inorganic materials 0.000 description 2
- 229910002535 CuZn Inorganic materials 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000002135 nanosheet Substances 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 229910018989 CoSb Inorganic materials 0.000 description 1
- 229910018985 CoSb3 Inorganic materials 0.000 description 1
- 229910017639 MgSi Inorganic materials 0.000 description 1
- 235000010724 Wisteria floribunda Nutrition 0.000 description 1
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 1
- 229910052769 Ytterbium Inorganic materials 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- 229910000416 bismuth oxide Inorganic materials 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- TYIXMATWDRGMPF-UHFFFAOYSA-N dibismuth;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Bi+3].[Bi+3] TYIXMATWDRGMPF-UHFFFAOYSA-N 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 238000009616 inductively coupled plasma Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000000550 scanning electron microscopy energy dispersive X-ray spectroscopy Methods 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 238000010671 solid-state reaction Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 229910052712 strontium Inorganic materials 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 229910000855 zintl phase Inorganic materials 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/85—Thermoelectric active materials
- H10N10/851—Thermoelectric active materials comprising inorganic compositions
- H10N10/853—Thermoelectric active materials comprising inorganic compositions comprising arsenic, antimony or bismuth
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/01—Manufacture or treatment
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/81—Structural details of the junction
- H10N10/817—Structural details of the junction the junction being non-separable, e.g. being cemented, sintered or soldered
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/82—Connection of interconnections
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/85—Thermoelectric active materials
- H10N10/851—Thermoelectric active materials comprising inorganic compositions
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/85—Thermoelectric active materials
- H10N10/851—Thermoelectric active materials comprising inorganic compositions
- H10N10/855—Thermoelectric active materials comprising inorganic compositions comprising compounds containing boron, carbon, oxygen or nitrogen
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/85—Thermoelectric active materials
- H10N10/857—Thermoelectric active materials comprising compositions changing continuously or discontinuously inside the material
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N19/00—Integrated devices, or assemblies of multiple devices, comprising at least one thermoelectric or thermomagnetic element covered by groups H10N10/00 - H10N15/00
Definitions
- thermoelectric conversion element a thermoelectric conversion module
- method for manufacturing a thermoelectric conversion element a thermoelectric conversion element
- thermoelectric conversion elements are known.
- a thermoelectric conversion module is used in which a p-type thermoelectric conversion element made of a p-type thermoelectric conversion material and an n-type thermoelectric conversion element made of an n-type thermoelectric conversion material are electrically connected.
- This thermoelectric conversion module enables power generation based on the temperature difference caused by the inflow of thermal energy.
- a metal member may be previously bonded to the end face portion of the thermoelectric conversion material using a bonding material or the like. It is easy to handle or assemble a thermoelectric conversion element whose end faces are metal members.
- Patent Document 1 discloses a thermoelectric conversion element configured by bonding a thermoelectric conversion material having a CoSb 3 -based alloy as a main phase and a Cu electrode with an Al—Si-based bonding material.
- Patent Document 2 discloses a thermoelectric conversion element configured by joining an n-type thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase and a metal member made of a CuZn alloy. .
- Patent Document 3 discloses an n-type thermoelectric conversion material containing carbon and having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase.
- Non-Patent Document 1 discloses a p-type thermoelectric conversion material containing graphene nanosheets and having an Sb-rich Mg 3 (Sb, Bi) 2 -based alloy as a main phase.
- An object of the present disclosure is to provide a novel thermoelectric conversion element.
- thermoelectric conversion layer a P-type thermoelectric conversion layer; a first metal layer; a second metal layer; a first bonding layer that bonds the first surface of the thermoelectric conversion layer and the first metal layer; a second bonding layer that bonds the second surface of the thermoelectric conversion layer and the second metal layer;
- a thermoelectric conversion element comprising The thermoelectric conversion layer has an alloy containing Mg and at least one of Sb and Bi as a main phase, and is made of a P-type thermoelectric conversion material containing carbon, at least one of the first bonding layer and the second bonding layer contains Al and Si; A thermoelectric conversion element is provided.
- thermoelectric conversion element According to the present disclosure, a novel thermoelectric conversion element can be provided.
- FIG. 1 is a schematic diagram showing an example of the thermoelectric conversion element of the present disclosure.
- FIG. 2 is a schematic diagram of the La 2 O 3 -type crystal structure of the present disclosure.
- FIG. 3 is a diagram showing the Raman spectroscopy spectrum of the thermoelectric conversion material of the present disclosure.
- FIG. 4 is a schematic diagram showing an example of the thermoelectric conversion module of the present disclosure.
- FIG. 5 is a schematic diagram showing a modification of the thermoelectric conversion module of the present disclosure.
- FIG. 6 is a schematic diagram showing one form of use of the thermoelectric conversion module of the present disclosure.
- FIG. 7 is a process drawing showing an example of a method for producing the thermoelectric conversion material of the present disclosure.
- FIG. 1 is a schematic diagram showing an example of the thermoelectric conversion element of the present disclosure.
- FIG. 2 is a schematic diagram of the La 2 O 3 -type crystal structure of the present disclosure.
- FIG. 3 is a diagram showing the Raman spectroscopy spectrum of the thermoelectric conversion
- FIG. 8 is a process drawing showing an example of a method for manufacturing the thermoelectric conversion element of the present disclosure.
- FIG. 9 is a schematic diagram showing an example of a method for manufacturing the thermoelectric conversion element of the present disclosure.
- FIG. 10 is a schematic diagram showing a modification of the method for manufacturing the thermoelectric conversion element of the present disclosure.
- FIG. 11 is an observation view after a durability test of the thermoelectric conversion element produced in Example 1.
- FIG. FIG. 12 is an observation view of the thermoelectric conversion element produced in Comparative Example 1 after the durability test.
- thermoelectric conversion material containing a Mg 3 (Sb, Bi) 2 -based alloy as a main phase has high thermoelectric conversion characteristics up to about 400°C.
- thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase deteriorates due to decomposition of the compound at 527° C. or higher, and the thermoelectric conversion characteristics are lowered.
- thermoelectric conversion element using a thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase must be used at 400° C. or higher in order to achieve high thermoelectric conversion characteristics, and must be resistant to decomposition. It is desirable to be used at a temperature of 520°C or less, which is durable.
- the criteria for selecting the bonding material used to fabricate the thermoelectric conversion element are that it has heat resistance up to the upper limit temperature for use of the element, and that it can be bonded at 520°C or less, which is the temperature at which the element does not deteriorate.
- thermoelectric conversion element using a bonding material composed of an AlSi alloy and a thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase had a low resistance at room temperature and good initial characteristics. .
- the bonding material composed of the AlSi alloy and the thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as the main phase It was found that the thermoelectric conversion element used was decomposed. Therefore, a thermoelectric conversion element using a thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase requires further measures to suppress decomposition when using an AlSi alloy as a bonding material. .
- Patent Document 1 discloses a thermoelectric conversion element configured by bonding a thermoelectric conversion material having a CoSb3-based alloy as a main phase and a Cu electrode with an Al—Si based bonding material. There is no report on the decomposition of the thermoelectric conversion element using .
- Patent Document 2 discloses a thermoelectric conversion element configured by joining an n-type thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase and a metal member made of a CuZn alloy.
- a thermoelectric conversion element using a thermoelectric conversion material having an Mg 3 (Sb, Bi) 2 system alloy as a main phase and using an AlSi alloy as a bonding material.
- Patent Document 3 discloses a thermoelectric conversion material whose main phase is an n-type Mg 3 (Sb, Bi) 2 alloy containing carbon. Bi) There is no report on a thermoelectric conversion material having a 2 -system alloy as a main phase.
- Non-Patent Document 1 discloses a p-type thermoelectric conversion material containing graphene nanosheets with an Sb-rich Mg 3 (Sb, Bi) 2 alloy as the main phase. There is no report about the decomposition of the thermoelectric conversion element in the presence of heat.
- thermoelectric conversion material having an n-type Mg 3 (Sb, Bi) 2 system alloy as a main phase as disclosed in Patent Document 2 and Patent Document 3 and AlSi It is considered that an n-type thermoelectric conversion element using an alloy cannot function as an element. This is because Si in the AlSi alloy reacts with Mg to form MgSi, which causes Mg deficiency and easily becomes p-type.
- thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase, a bonding material composed of an AlSi alloy and Mg 3 (Sb, Bi) 2
- a thermoelectric conversion element using a thermoelectric conversion material whose main phase is a system alloy can suppress decomposition in the air at 450°C.
- a thermoelectric conversion element using a bonding material composed of an AlSi alloy and a thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase can be used at high temperatures such as 400 ° C. or higher and 520 ° C. or lower. can be stably obtained even under the conditions of
- FIG. 1 is a schematic diagram showing an example of a thermoelectric conversion element according to an embodiment of the present disclosure.
- a thermoelectric conversion element 10a shown in FIG. 1 includes a thermoelectric conversion layer 11, a first metal layer 14a, a second metal layer 14b, a first bonding layer 13a, and a second bonding layer 13b.
- the first bonding layer 13a bonds the first surface 12a of the thermoelectric conversion layer 11 and the first metal layer 14a.
- the second bonding layer 13b bonds the second surface 12b of the thermoelectric conversion layer 11 and the second metal layer 14b.
- the shape of the thermoelectric conversion element 10a is, for example, a rectangular parallelepiped.
- the shape of the thermoelectric conversion element 10a may be, for example, a cube, another prism, a cylinder, or a cylinder, as long as it is a three-dimensional shape that can form layers.
- thermoelectric conversion layer 11 is a middle layer portion of the thermoelectric conversion element 10a, and the thickness of the thermoelectric conversion element 10a is, for example, 0.5 mm or more and 5.0 mm or less. In other words, the thickness of the thermoelectric conversion element 10a satisfies the formula 0.5 mm ⁇ tE ⁇ 5.0 mm, for example.
- tE represents the thickness of the thermoelectric conversion element 10a of the present disclosure.
- the thermoelectric conversion layer 11 is made of a thermoelectric conversion material containing carbon, with an alloy containing Mg and at least one of Sb and Bi as the main phase.
- the thermoelectric conversion material of the present disclosure is a p-type thermoelectric conversion material.
- the content of Mg, Sb and Bi in the thermoelectric conversion material can be determined, for example, by X-ray diffraction method (XRD) or SEM-EDX combining scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). can be determined according to
- thermoelectric conversion material of the present disclosure may be a thermoelectric conversion material whose main phase is an alloy containing Mg and at least one of Sb and Bi, and has a subphase composed of another alloy.
- the thermoelectric conversion material of the present disclosure has, for example, a Mg 3 (Sb, Bi) 2 -based alloy as a main phase.
- Mg3 (Sb,Bi) 2 -based alloys include materials in which some elements of Mg3 (Sb,Bi) 2 and Mg3 (Sb,Bi) 2 are replaced with other elements.
- the Mg 3 (Sb, Bi) 2 -based alloy is a material in which some elements of Mg 3 (Sb, Bi) 2 are replaced with other elements, the content of the other elements is It is less than the content of Mg and less than the sum of the content of Sb and the content of Bi.
- the Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material is desirably used at a temperature of 520° C. or less, which has durability against decomposition.
- a Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material containing more Sb than Bi (that is, Sb-rich) is expected to have high thermoelectric properties in a temperature range of 400° C. or higher. Therefore, the operating temperature range of the Sb-rich Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material is preferably 300° C. or higher and 520° C. or lower, more preferably 350° C. or higher and 520° C. or lower, and still more preferably It is 400° C. or more and 520° C. or less.
- the operating temperature range t1 of the Sb-rich Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material preferably satisfies the condition of 300°C ⁇ t1 ⁇ 520°C, more preferably 350°C ⁇ t1 ⁇ 520°C. and more preferably 400°C ⁇ t1 ⁇ 520°C.
- the operating temperature range of the Bi-rich Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material is preferably 200° C. or higher and 520° C. or lower, more preferably 300° C. or higher and 520° C. or lower, and still more preferably It is 300° C. or more and 500° C. or less.
- the usage temperature range t2 of the Bi-rich Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material preferably satisfies the condition of 200°C ⁇ t2 ⁇ 520°C, more preferably 300°C ⁇ t2 ⁇ 520°C. and more preferably 300°C ⁇ t2 ⁇ 500°C.
- the operating temperature range of the Bi-rich Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material is preferably 200° C. or higher and 520° C. or lower, more preferably 300° C. or higher and 520° C. or lower, and still more preferably It is 300° C. or more and 500° C. or less.
- the usage temperature range t2 of the Bi-rich Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material preferably satisfies the condition of 200°C ⁇ t2 ⁇ 520°C, more preferably 300°C ⁇ t2 ⁇ 520°C. and more preferably 300°C ⁇ t2 ⁇ 500°C.
- composition of the thermoelectric conversion material of the present disclosure may have a subphase or the like composed of another alloy when the main phase is a Mg 3 (Sb, Bi) 2 based alloy.
- thermoelectric conversion material of the present disclosure is represented by Formula (1): Mg 3-m A X Sb 2-Z Bi Z , for example.
- a in Formula (1) contains at least one element species selected from the group consisting of Na, Li, and Ag.
- the value of m in formula (1) is preferably -0.39 or more and 0.42 or less. More preferably, it is in the range of -0.39 or more and 0.30 or less. More preferably, it is in the range of -0.30 or more and 0.20 or less. In other words, the value of m preferably satisfies the formula -0.39 ⁇ m ⁇ 0.42. More preferably, the formula -0.39 ⁇ m ⁇ 0.30 is satisfied. More preferably, the formula -0.30 ⁇ m ⁇ 0.20 is satisfied.
- the value of x in formula (1) is preferably in the range of over 0 and 0.12 or less. More preferably, it is in the range of more than 0 and 0.10 or less. More preferably, it is in the range of 0.001 or more and 0.05 or less. In other words, the value of x preferably satisfies the formula 0 ⁇ x ⁇ 0.12. More preferably, the formula 0 ⁇ x ⁇ 0.10 is satisfied. More preferably, the formula 0.001 ⁇ x ⁇ 0.05 is satisfied.
- the value of z in formula (1) is preferably in the range of 0 or more and 2.0 or less. More preferably, it is in the range of 0.01 or more and less than 2.0. More preferably, it is in the range of 0.5 or more and less than 2.0. In other words, the value of z preferably satisfies the equation 0 ⁇ z ⁇ 2.0. More preferably, the formula 0.01 ⁇ z ⁇ 2.0 is satisfied. More preferably, the formula 0.5 ⁇ z ⁇ 2.0 is satisfied.
- thermoelectric conversion material of the present disclosure has a La 2 O 3 type crystal structure.
- FIG. 2 is a schematic diagram of the La 2 O 3 type crystal structure.
- Thermoelectric conversion materials according to the present disclosure may be monocrystalline or polycrystalline.
- each crystal grain that constitutes the thermoelectric conversion material has a La 2 O 3 type crystal structure.
- the La 2 O 3 type crystal structure in the thermoelectric conversion material of the present disclosure was clarified by X-ray diffraction measurement. According to the results of X-ray diffraction measurement, Mg is located at the C1 site, and at least one element of Sb and Bi is located at the C2 site. The C1 site and C2 site form a bond as indicated by the dotted line in FIG.
- the first metal layer 14a and the second metal layer 14b shown in FIG. 1 are end faces of the thermoelectric conversion element 10a.
- the thickness of each layer of the first metal layer 14a and the second metal layer 14b is, for example, 0.005 mm or more and 0.3 mm or less, and may be 0.005 mm or more and 0.2 mm or less.
- the thickness of each layer of the first metal layer 14a and the second metal layer 14b satisfies, for example, the formula 0.005 mm ⁇ tM ⁇ 0.3 mm and the formula 0.005 mm ⁇ tM ⁇ 0.2 mm.
- tM represents the thickness of each layer of the first metal layer 14a and the second metal layer 14b of the present disclosure.
- the thickness of each layer may be the same or different.
- the first metal layer 14a of the present disclosure is not limited to a specific material.
- the first metal layer 14a contains Cu or a Cu alloy, for example.
- the second metal layer 14b of the present disclosure is not limited to a specific material.
- the second metal layer 14b contains Cu or a Cu alloy, for example.
- the first metal layer 14a and the second metal layer 14b may contain impurities of 1% or less.
- Impurities are, for example, metal impurities such as Al, Fe, Co, or Ni.
- Impurities are, as another example, non-metallic impurities such as oxygen or carbon.
- the first bonding layer 13a is between the first surface 12a of the thermoelectric conversion layer 11 and the first metal layer 14a. Desirably, the first bonding layer 13a is in direct contact with the first surface 12a of the thermoelectric conversion layer 11 .
- the first bonding layer 13a may be in direct contact with the first metal layer 14a, or may not be in direct contact with the interposition of a diffusion layer or the like.
- the second bonding layer 13b is between the second surface 12b of the thermoelectric conversion layer 11 and the second metal layer 14b. Desirably, the second bonding layer 13b is in direct contact with the second surface 12b of the thermoelectric conversion layer 11 .
- the second bonding layer 13b may be in direct contact with the second metal layer 14b, or may not be in direct contact with the interposition of a diffusion layer or the like.
- At least one of the first bonding layer and the second bonding layer contains Al and Si.
- Si contained in at least one of the first bonding layer and the second bonding layer provided in the thermoelectric conversion element of the present disclosure is preferably more than 0.0 at % and 25.0 at % or less. More preferably, it is 5.0 at % or more and 20.0 at % or less. More preferably, it is 5.0 at % or more and 15.0 at % or less. In other words, at least one of the first bonding layer and the second bonding layer of the present disclosure preferably satisfies the formula 0.0at% ⁇ SC ⁇ 25.0at%.
- SC represents the content ratio of Si contained in at least one of the first bonding layer and the second bonding layer provided in the thermoelectric conversion element of the present disclosure. More preferably, the formula 5.0at% ⁇ SC ⁇ 20.0at% is satisfied. More preferably, the formula 5.0at% ⁇ SC ⁇ 15.0at% is satisfied.
- each layer of the first bonding layer 13a and the second bonding layer 13b is, for example, 0.01 mm or more and 0.3 mm or less.
- the thickness of each layer of the first bonding layer 13a and the second bonding layer 13b satisfies the formula 0.01 mm ⁇ tB ⁇ 0.3 mm, for example.
- tB represents the thickness of each layer of the first bonding layer 13a and the second bonding layer 13b of the present disclosure.
- Carbon contained in the thermoelectric conversion material of the present disclosure is preferably a carbon material having at least one allotrope such as graphene or graphite. More preferably, it is a carbon material containing graphite, which is an allotrope, as a main component. Carbon is contained, for example, inside or at the grain boundary of each crystal grain that constitutes the thermoelectric conversion material of the present disclosure.
- the carbon contained in the thermoelectric conversion material of the present disclosure is 0.01 at% or more and 1.2 at% or less. More preferably, it is 0.1 at % or more and 1.0 at % or less. More preferably, it is 0.1 at % or more and 0.8 at % or less.
- the thermoelectric conversion material of the present disclosure preferably satisfies the formula 0.01at% ⁇ CC ⁇ 1.2at%.
- CC represents the content of carbon in the thermoelectric conversion material of the present disclosure. More preferably, the formula 0.10at% ⁇ CC ⁇ 1.0at% is satisfied. More preferably, the formula 0.10at% ⁇ CC ⁇ 0.8at% is satisfied.
- the mass ratio of the thermoelectric conversion material is 100 or less with respect to the mass ratio of carbon of 1. More preferably, the mass ratio of carbon to thermoelectric conversion material is 1:80 or less.
- FIG. 3 shows the results of Raman spectroscopy for determining the presence or absence of carbon.
- the wavelength of the light source used in Raman spectroscopy is 488 nm.
- the peak around 180 cm ⁇ 1 shown in FIG. 2 is the peak representing the Mg 3 (Sb, Bi) 2 alloy.
- two peaks near 1300 to 1650 cm ⁇ 1 shown in FIG. 2 are peaks representing carbon.
- thermoelectric conversion material of the present disclosure is indicated by a solid line (legend: solid line).
- a solid line legend: solid line.
- the thermoelectric conversion material of the present disclosure when the peak intensity of the Mg 3 (Sb, Bi) 2 alloy is 1000, at least one of the two carbon peak intensities is 500 or more. is judged to contain carbon.
- the thermoelectric conversion material of the present disclosure satisfies the formula (M2) 0.5 ⁇ IC/IM.
- IC represents the peak intensity of the carbon in the Raman spectrum
- IM represents the peak intensity of the Mg 3 (Sb, Bi) 2 based alloy in the Raman spectrum.
- thermoelectric conversion material containing no carbon is indicated by a dashed line (legend: dashed line).
- a carbon peak may be observed by using a sintered mold made of carbon.
- the peak intensity of Mg 3 (Sb, Bi) 2 based alloy is 1000, the peak intensity of carbon is less than 500.
- a carbon-free Mg 3 (Sb, Bi) 2 -based thermoelectric conversion material satisfies the formula (M3) 0.5>IC/IM.
- thermoelectric conversion material containing no carbon and thermoelectric conversion material containing carbon of the present disclosure can be distinguished.
- thermoelectric conversion module A thermoelectric conversion module in which the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the present disclosure are electrically connected can be provided.
- FIG. 4 shows an example of the thermoelectric conversion module of the present disclosure.
- the thermoelectric conversion module 100 includes the p-type thermoelectric conversion element 10a and the n-type thermoelectric conversion element 20a, as shown in FIG. and The p-type thermoelectric conversion element 10a and the n-type thermoelectric conversion element 20a are electrically connected in series.
- the p-type thermoelectric conversion element 10a and the n-type thermoelectric conversion element 20a are electrically connected by an external electrode 31, for example.
- the n-type thermoelectric conversion element 20a includes an n-type thermoelectric conversion layer 21, a third metal layer 24a, a fourth metal layer 24b, a third bonding layer 23a, and a fourth bonding layer 23b.
- the third bonding layer 23a bonds the third surface 22a of the n-type thermoelectric conversion layer 21 and the third metal layer 24a.
- the fourth bonding layer 23b bonds the fourth surface 22b of the n-type thermoelectric conversion layer 21 and the fourth metal layer 24b.
- the n-type thermoelectric conversion layer 21 in the present disclosure is made of, for example, an n-type thermoelectric conversion material whose main phase is an alloy containing Mg and at least one of Sb and Bi. More specifically, for example, it is made of an n-type thermoelectric conversion material containing a Mg 3 (Sb, Bi) 2 -based alloy as a main phase.
- thermoelectric conversion module 100 the atomic ratios of Sb and Bi contained in the p-type thermoelectric conversion material and the n-type thermoelectric conversion material that form a pair may or may not match.
- the ratio of the number of atoms is the same, the difference in thermal expansion coefficient between the p-type thermoelectric conversion material and the n-type thermoelectric conversion material tends to be small. Therefore, the thermal stress generated in the thermoelectric conversion module is likely to be reduced.
- composition of the n-type thermoelectric conversion material in the present disclosure is not limited to a specific composition.
- composition of the n-type thermoelectric conversion material of the present disclosure is represented, for example, by Formula (3): Mg 3+m R a T b X 2-e Ze .
- R in formula (3) contains at least one element species selected from the group consisting of Ca, Sr, Ba, and Yb.
- T in the formula (3) contains at least one element species selected from the group consisting of Mn and Zn.
- X in formula (3) contains at least one element species selected from the group consisting of Sb and Bi.
- Z in the formula (3) contains at least one element species selected from the group consisting of Se and Te.
- the value of m in formula (3) is -0.39 or more and 0.42 or less. In other words, the value of m satisfies the formula -0.39 ⁇ m ⁇ 0.42.
- the value of a in formula (3) is 0 or more and 0.12 or less. In other words, the value of a satisfies the equation 0 ⁇ a ⁇ 0.12.
- the value of b in formula (3) is 0 or more and 0.48 or less. In other words, the value of b satisfies the equation 0 ⁇ b ⁇ 0.48.
- the value of e in formula (3) is 0.001 or more and 0.06 or less. In other words, the value of e satisfies the formula 0.001 ⁇ e ⁇ 0.06.
- the n-type thermoelectric conversion material of the present disclosure can have any composition within the range of formula (3).
- the n-type thermoelectric conversion material of the present disclosure is also desirably a thermoelectric conversion material having a Mg 3 (Sb, Bi) 2 -based alloy as a main phase.
- the n-type thermoelectric conversion material also has a La 2 O 3 type crystal structure.
- the n-type thermoelectric conversion material may be monocrystalline or polycrystalline.
- the third metal layer 24a and the fourth metal layer 24b are end faces of the n-type thermoelectric conversion element 20a.
- the thickness of each layer of the third metal layer 24a and the fourth metal layer 24b is, for example, 0.005 mm or more and 2 mm or less.
- the thickness of each layer of the third metal layer 24a and the fourth metal layer 24b may be the same or different.
- composition of the third metal layer 24a and the composition of the fourth metal layer 24b may be the same as the composition of the first metal layer 14a and the composition of the second metal layer 14b, respectively. In this case, electrical connection with the external electrodes can be simplified.
- FIG. 5 shows a modification of the thermoelectric conversion module according to the present disclosure.
- the thermoelectric conversion module 200 includes the p-type thermoelectric conversion element 10a and the n-type thermoelectric conversion element 20b, as shown in FIG. are electrically connected by the external electrode 31 .
- the n-type thermoelectric conversion element 20b includes an n-type thermoelectric conversion layer 21, a third metal layer 24a, and a fourth metal layer 24b. As shown in FIG. 5, in the n-type thermoelectric conversion element 20b, the third surface 22a of the n-type thermoelectric conversion layer 21 and the third metal layer 24a are directly bonded. Similarly, the fourth surface 22b of the n-type thermoelectric conversion layer 21 and the fourth metal layer 24b are directly bonded.
- both the p-type thermoelectric conversion element 10a and the n-type thermoelectric conversion element 20a may include bonding layers, like the thermoelectric conversion module 100 of FIG.
- only the p-type thermoelectric conversion elements 10a may include the bonding layer as in the thermoelectric conversion module 200 of FIG.
- FIG. 6 shows one form of use of the thermoelectric conversion module 100 of the present disclosure.
- the p-type thermoelectric conversion element 10a is electrically connected to the external electrode 32 by the second metal layer 14b.
- the n-type thermoelectric conversion element 20a is electrically connected to the external electrode 33 by the fourth metal layer 24b.
- the first wiring 41 and the second wiring 42 play a role of extracting electric power generated in the p-type thermoelectric conversion element 10a and the n-type thermoelectric conversion element 20a to the outside.
- the second wiring 42 is connected to the external electrode 33 .
- thermoelectric conversion material is not limited to a specific method.
- the thermoelectric conversion material is, for example, an alloy powder containing Mg, at least one of Sb and Bi, and carbon, is energized by a spark plasma sintering method (SPS), and the alloy powder is sintered at a temperature of 500 ° C. or higher.
- SPS spark plasma sintering method
- the thermoelectric conversion material has an alloy containing Mg and at least one of Sb and Bi as a main phase, contains carbon, and is p-type.
- the thermoelectric conversion material has, for example, a Mg 3 (Sb, Bi) 2 -based alloy as a main phase, contains carbon, and is p-type.
- the alloy powder is, for example, polycrystalline powder. In SPS, the alloy powder is filled into a die made of carbon, for example.
- a predetermined pressure is applied to the alloy powder during sintering. The magnitude of the pressure is, for example, 10 MPa to 100 MPa.
- the sintering temperature of the alloy powder in sintering is, for example, lower than the melting temperature of the alloy, for example, 700° C. or less.
- the energization time for the alloy powder in sintering is not limited to a specific value. The energization time is, for example, 2 minutes to 1 hour.
- FIG. 7 shows a process diagram of a method for manufacturing the thermoelectric conversion material of the present disclosure.
- FIG. 7 shows in more detail one example of the method of manufacturing the thermoelectric conversion material of the present disclosure.
- the method for producing the thermoelectric conversion material of the present disclosure is not limited to the examples below.
- a powdery MgSbBiA alloy is obtained by a solid phase reaction of raw materials Mg particles, Sb particles, Bi particles, and dope material A powder.
- An example of the solid-phase reaction method is the mechanical alloying method.
- another method such as a melting method may be adopted as a method of solid-phase reaction.
- step S2 the powder MgSbBiA alloy and carbon are mixed.
- An example of the mixing method is the mechanical alloying method.
- As a mixing method another method such as a ball mill method may be adopted.
- step S3 the precursor powder, which is a mixture of MgSbBiA and carbon, is subjected to sintering to obtain single crystals or polycrystals of MgSbBiA and carbon.
- sintering for example, a spark plasma sintering method or a hot press method can be adopted.
- the obtained sintered body may be used as a thermoelectric conversion material as it is. Further, heat treatment may be performed on the obtained sintered body. In this case, the sintered body after heat treatment can also be used as a thermoelectric conversion material.
- FIG. 8 shows a process diagram of a method for manufacturing a thermoelectric conversion element of the present disclosure.
- FIG. 9 shows an example of a method for manufacturing the thermoelectric conversion element of the present disclosure. This method is described below. However, the method of manufacturing the thermoelectric conversion element of the present disclosure is not limited to the following examples.
- step S10 in FIG. 8 the mold 50 in FIG. of material 14d are filled in this order. This filling is done under an inert atmosphere. After sintering, the material 11c of the thermoelectric conversion layer is subjected to surface oxide film removal treatment.
- the sintering temperature of the thermoelectric conversion material can be made higher than 500°C. If the sintering temperature is higher than 500° C., the thermoelectric conversion material is a polycrystalline body, and if the polycrystalline body is kept at a high temperature, the crystal grains become coarse. That is, grain growth occurs. A thermoelectric conversion material composed of grown crystal grains may have improved thermoelectric properties.
- the bonding temperature is preferably 300° C. or higher and 500° C.
- the junction temperature in the manufacturing method of the thermoelectric conversion element of the present disclosure preferably satisfies 300°C ⁇ t ⁇ 500°C.
- t represents the bonding temperature for obtaining the laminate. More preferably, 400°C ⁇ t ⁇ 450°C is satisfied. More preferably, 410°C ⁇ t ⁇ 430°C is satisfied.
- the shape may be devised so that the contact area of the materials that make up each layer is large.
- the material constituting the first bonding layer and the second bonding layer is powdered to form the first metal layer and the second metal layer.
- the material to be used is plate-like, lump-like, or powder-like.
- step S20 the above-described material filled in the mold 50 is heated and pressurized at a predetermined temperature to obtain a joined body.
- sintering is performed in an inert atmosphere by pressing the material in the pressing direction 51 indicated by the black arrow and applying a current 52 corresponding to the bonding temperature in the direction of the white arrow.
- a sintering method for example, a spark plasma sintering method or a hot press method can be adopted.
- thermoelectric conversion element which is a laminated body bonded by sintering, is removed from the mold 50.
- FIG. 10 shows a modification of the method for manufacturing the thermoelectric conversion element of the present disclosure.
- a precursor powder which is a mixture of powder MgSbBiA before sintering and carbon, is used as a material for the thermoelectric conversion layer.
- the mold 50 is filled with the material 14c for the first metal layer, the material 13c for the first bonding layer, the material 11c for the thermoelectric conversion layer, the material 13d for the second bonding layer, and the material 14d for the second metal layer in this order. do.
- This filling is done in an inert atmosphere.
- the material is pressed in a pressing direction 51 indicated by a black arrow, and a current 52 corresponding to the joining temperature is applied in the direction indicated by a white arrow to perform joining.
- a spark plasma sintering method or a hot press method can be adopted. According to this modification, the sintering of the thermoelectric conversion material, the sintering of the thermoelectric conversion material, and the joining of the thermoelectric conversion layer and the metal layer can be performed at once, thereby simplifying the process.
- thermoelectric conversion element of the present disclosure shown in FIGS. 9 and 10
- the material is pressed and joined in the upward and downward pressing directions 51 indicated by black arrows.
- the magnitude of the pressure in the upward and downward directions is the same.
- the magnitude of pressurization may be the same or may be different.
- thermoelectric conversion layer the first metal layer and the second metal layer are joined (step S20)
- annealing is performed in an inert atmosphere to remove residual stress, thereby removing thermoelectric conversion. Homogenization within the element may be achieved.
- thermoelectric conversion modules 100 and 200 can be assembled and manufactured by a known method using the n-type thermoelectric conversion element 20a or 20b and the p-type thermoelectric conversion element 10a.
- composition analysis evaluation of each layer in the thermoelectric conversion material after sintering and the thermoelectric conversion element after bonding Composition analysis and evaluation of each layer in the thermoelectric conversion material after sintering and the thermoelectric conversion element after bonding can be performed.
- Techniques for this compositional analysis evaluation are, for example, Raman spectroscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma emission spectroscopy. These techniques can also be applied to thermoelectric conversion modules after production.
- thermoelectric conversion element of the present disclosure is not limited.
- the thermoelectric conversion element of the present disclosure can be used in various applications including, for example, conventional thermoelectric conversion elements.
- thermoelectric conversion layer 4 g of Mg 2.99 Na 0.01 Sb 1.0 Bi 1.0 prepared by solid phase reaction and 0.1 g of carbon powder (20 ⁇ m powder manufactured by Kojundo Chemical Co., Ltd.) were weighed inside a glove box. The inside of the glove box was controlled to an argon atmosphere until the thermoelectric conversion material was obtained. Next, each weighed material was enclosed in a stainless container for mechanical alloying together with stainless balls in a glove box. After that, it was made into a mixed powder by a normal temperature pulverizer (manufactured by SPEX, model: 8000D type). Next, the mixed powder was filled into a sintering space of a carbon die and compacted using a carbon punch. The die was a sintered mold with a diameter of 10 mm.
- the die was housed in the chamber of a spark plasma sintering device (Model: SPS515S manufactured by Fuji Denpa Koki Co., Ltd.).
- the chamber was controlled to an argon atmosphere.
- a current was then applied to the die by the sintering device while a pressure of 50 MPa was applied to the die packing. Due to the application of current, the temperature of the die reached the sintering temperature of 680° C. and was maintained at that temperature for 10 minutes. Heating was then stopped by gradually reducing the current. After confirming that the temperature of the die had dropped to room temperature, the sintered body was removed from the die.
- a surface oxide layer forming a surface of the sintered body, which is a thermoelectric conversion material, in contact with the sintering mold was polished, and then the sintered body was washed with acetone.
- the thickness of the sintered body was about 5 mm.
- the Cu plate had a diameter of 10 mm and a thickness of 0.2 mm.
- the AlSi powder contained 88% Al and 12% Si by weight.
- the sintering space of a carbon die is filled with one Cu plate, AlSi powder, thermoelectric conversion material, AlSi powder, and one Cu plate in this order, and punched. Compacted with The Cu plate was the material for the metal layer, and the AlSi powder was the material for the bonding layer.
- the die was placed in the chamber of the spark plasma sintering device.
- the chamber was controlled to an argon atmosphere.
- a current was then applied to the die by the sintering device while applying a pressure of 50 MPa to the die packing. Due to the application of current, the temperature of the die reached the maximum junction temperature of 400° C. and was maintained at that temperature for 5 minutes. Heating of the die was then stopped by gradually reducing the current. After the temperature of the die was lowered to room temperature, the thermoelectric conversion element substrate as a laminate was taken out from the die.
- thermoelectric conversion element The thermoelectric conversion element substrate after sintering was cut into a size of 4.3 mm ⁇ 3.6 mm ⁇ 2.7 mm. After polishing the machined surface of the thermoelectric conversion element after cutting, it was washed with acetone. Using a KEITHLEY source meter (model number: 3400), the electrical resistance value of the thermoelectric conversion element was measured according to the four-terminal measurement method. As a result, it was 41 m ⁇ .
- thermoelectric conversion element As a durability test, the thermoelectric conversion element was heated for 2 hours in the air at 450° C., which is close to the upper limit of the operating temperature of the thermoelectric conversion element.
- FIG. 11 is an observation view after a durability test of the thermoelectric conversion element produced in Example 1.
- thermoelectric conversion material was produced in the same manner as in Example 1, except that 4 g of Mg 2.99 Na 0.01 Sb 1.0 Bi 1.0 produced by solid-state reaction was weighed inside the glove box. .
- thermoelectric conversion element substrate as a laminate was obtained in the same manner as in Example 1.
- thermoelectric conversion element The thermoelectric conversion element substrate after sintering was cut into a size of 3.5 mm ⁇ 3.4 mm ⁇ 3.4 mm. After that, the electrical resistance value of the thermoelectric conversion element was measured in the same manner as in Example 1. As a result, it was 30 m ⁇ .
- thermoelectric conversion element As in Example 1, as a durability test, the thermoelectric conversion element was heated for 2 hours in the air at 450° C., which is close to the upper limit of the operating temperature of the thermoelectric conversion element, and the thermoelectric conversion element was decomposed.
- FIG. 12 is an observation view of the thermoelectric conversion element produced in Comparative Example 1 after the durability test. That is, as shown in FIG. 12, the entire device was in the form of yellow and black powder, and the resistance could not be measured.
- the decomposed yellow powder was analyzed by X-ray diffraction (manufactured by Malvern Panalytica, model number: benchtop X-ray diffractometer Aeris), a peak thought to be bismuth oxide was observed.
- thermoelectric conversion element of the present disclosure can be used for various uses including conventional thermoelectric conversion elements.
- Thermoelectric conversion element 11 Thermoelectric conversion layer 11c Thermoelectric conversion layer material 12a First surface 12b Second surface 13a First bonding layer 13b Second bonding layer 13c First bonding layer material 13d Second bonding layer material 14a First metal Layer 14b Second metal layer 14c First metal layer material 14d Second metal layer material 100, 200 Thermoelectric conversion modules 20a, 20b N-type thermoelectric conversion element 21 N-type thermoelectric conversion layer 22a Third surface 22b Fourth surface 23a Third bonding layer 23b Fourth bonding layer 24a Third metal layer 24b Fourth metal layer 31, 32, 33 External electrode 41 First wiring 42 Second wiring 50 Mold 51 Pressing direction 52 Current
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
P型の熱電変換層と、
第1金属層と、
第2金属層と、
前記熱電変換層の第1面及び前記第1金属層を接合する第1接合層と、
前記熱電変換層の第2面及び前記第2金属層を接合する第2接合層と、
を具備する熱電変換素子であって、
前記熱電変換層は、Mgと、Sb及びBiの少なくとも一方とを含有する合金を主相とし、かつ、炭素を含むP型の熱電変換材料からなり、
前記第1接合層及び前記第2接合層の少なくとも一方は、Al及びSiを含有する、
熱電変換素子を提供する。
Mg3(Sb,Bi)2系合金を主相とする熱電変換材料は、400℃程度まで高い熱電変換特性がある。一方で、Mg3(Sb,Bi)2系合金を主相とする熱電変換材料は、527℃以上になると化合物の分解によって劣化し、熱電変換特性が下がる。
以下、本開示の実施形態について図面を参照しながら説明する。
図1は、本開示の実施形態による熱電変換素子の一例を示す模式図である。図1に示す熱電変換素子10aは、熱電変換層11、第1金属層14a、第2金属層14b、第1接合層13a、及び第2接合層13bを具備する。第1接合層13aは、熱電変換層11の第1面12aと第1金属層14aとを接合する。第2接合層13bは、熱電変換層11の第2面12bと第2金属層14bとを接合する。
熱電変換層11は、熱電変換素子10aの中層部であり、熱電変換素子10aの厚さは、例えば0.5mm以上5.0mm以下である。言い換えれば、熱電変換素子10aの厚さは、例えば、数式0.5mm≦tE≦5.0mmが充足される。ここで、tEは、本開示の熱電変換素子10aの厚さを表す。
図1に示される第1金属層14a及び第2金属層14bは、熱電変換素子10aの端面部である。第1金属層14a及び第2金属層14bの各層の厚さは、例えば0.005mm以上0.3mm以下であり、0.005mm以上0.2mm以下であってもよい。言い換えれば、第1金属層14a及び第2金属層14bの各層の厚さは、例えば、数式0.005mm≦tM≦0.3mmが充足され、数式0.005mm≦tM≦0.2mmが充足される。ここで、tMは、本開示の第1金属層14a及び第2金属層14bの各層の厚さを表す。各層の厚さは同じであっても、異なっていても良い。
図1に示す通り、第1接合層13aは、熱電変換層11の第1面12aと第1金属層14aとの間にある。望ましくは、第1接合層13aは、熱電変換層11の第1面12aと直接的に接している。第1接合層13aは、第1金属層14aと直接的に接していてもよいし、拡散層などの介在により直接的に接していなくてもよい。第2接合層13bは、熱電変換層11の第2面12bと第2金属層14bとの間にある。望ましくは、第2接合層13bは、熱電変換層11の第2面12bと直接的に接している。第2接合層13bは、第2金属層14bと直接的に接していてもよいし、拡散層などの介在により直接的に接していなくてもよい。
本開示の熱電変換材料に含有される炭素は、グラフェン又はグラファイト等の同素体の少なくとも1つを具備する炭素材料であることが好ましい。より好ましくは、同素体であるグラファイトを主成分とする炭素材料である。炭素は、一例として、本開示の熱電変換材料を構成する各々の結晶粒の粒内又は粒界などに含有される。
本開示のp型の熱電変換素子と、n型の熱電変換素子と、が電気的に接続された熱電変換モジュールを提供できる。
[熱電変換材料の製造方法]
熱電変換材料を製造する方法は、特定の方法に限定されない。熱電変換材料は、例えば、Mgと、Sb及びBiの少なくとも一方と、炭素とを含有する合金粉末にスパークプラズマ焼結法(SPS)によって通電し、500℃以上の温度でその合金粉末を焼結することを含む製造方法によって製造される。熱電変換材料は、Mgと、Sb及びBiの少なくとも一方と含有する合金を主相とし、炭素を含有し、かつ、p型である。より具体的には、熱電変換材料は、例えば、Mg3(Sb,Bi)2系の合金を主相とし、炭素を含有し、かつ、p型である。合金粉末は、例えば、多結晶体の粉末である。SPSにおいて、合金粉末は、例えばカーボン製のダイに充填される。焼結において合金粉末には所定の圧力が印加される。その圧力の大きさは、例えば10MPaから100MPaである。焼結における合金粉末の焼結温度は、例えば合金の溶融温度未満であり、例えば700℃以下である。焼結における合金粉末への通電時間は、特定の値に限定されない。その通電時間は、例えば、2分間から1時間である。
図8は、本開示の熱電変換素子を製造する方法の工程図を示す。
焼結後の熱電変換材料及び接合後の熱電変換素子における各層の組成分析評価をすることができる。この組成分析評価の手法は、例えば、ラマン分光法、エネルギー分散X線分光法、X線光電子分光法及び誘電結合プラズマ発光分光法である。これらの手法は、製造後の熱電変換モジュールについても適用できる。
[熱電変換層の作製]
固相反応で作製されたMg2.99Na0.01Sb1.0Bi1.0 4g及び炭素粉末0.1g(高純度化学製 20μm粉末)をグローブボックス内部で秤量した。グローブボックス内部は熱電変換材料を得るまでの間、アルゴン雰囲気に制御されていた。次に秤量された各材料を、グローブボックス内にてメカニカルアロイング用のステンレス容器にステンレス球とともに封入した。その後、常温粉砕機(SPEX社製 型式:8000D型)によって混合粉末にした。次に混合粉末を、カーボン製のダイの焼結空間に充填し、カーボン製のパンチを用いて圧粉した。ダイは、10mmの直径を有する焼結型であった。
グローブボックスの内部に、表面酸化層の研磨を行った熱電変換材料、アセトン洗浄を施したCu板、及びAlSi粉末が移された。Cu板は、10mmの直径と、0.2mmの厚みを有していた。AlSi粉末は、質量基準で、88%のAl及び12%のSiを含有していた。グローブボックスの内部において、カーボン製のダイ(成形型)の焼結空間に、1枚のCu板、AlSi粉末、熱電変換材料、AlSi粉末、及び1枚のCu板をこの順番で充填し、パンチで圧粉した。Cu板は、金属層の材料であり、AlSi粉末は接合層の材料であった。
焼結後の熱電変換素子基板を切削し、4.3mm×3.6mm×2.7mmに加工した。切削後の熱電変換素子の加工表面を研磨した後、アセトンで洗浄を行った。KEITHLEY製ソースメータ(型番:3400)を用いて、4端子測定法に従って、熱電変換素子の電気抵抗値を測定した。その結果、41mΩであった。
耐久性テストとして、熱電変換素子の使用温度上限に近い450℃の大気中で2時間、熱電変換素子の加熱を行った。図11は、実施例1で作製された熱電変換素子の耐久性テスト後の観察図である。加熱により、Cu板の最表面が酸化していたため、研磨により酸化層を除去した後で電気抵抗値を測定した。その結果、耐久性テスト後の熱電変換材料の電気抵抗値は、40mΩであり、有意な変化はなかった。
[熱電変換層の作製]
固相反応で作製されたMg2.99Na0.01Sb1.0Bi1.0 4gをグローブボックスの内部で秤量したこと以外は、実施例1と同様にして、熱電変換材料を作製した。
実施例1と同様にして、積層体である熱電変換素子基板を得た。
焼結後の熱電変換素子基板を切削し、3.5mm×3.4mm×3.4mmに加工した。その後、実施例1と同様に、熱電変換素子の電気抵抗値を測定した。その結果、30mΩであった。
実施例1と同様に、耐久性テストとして、熱電変換素子の使用温度上限に近い450℃の大気中で2時間、熱電変換素子の加熱を行ったところ、熱電変換素子は分解した。図12は、比較例1で作製された熱電変換素子の耐久性テスト後の観察図である。すなわち、図12に示されるように、素子全体が黄色及び黒色の粉状になっており、抵抗を測定することができなかった。分解した黄色の粉をX線回折(Malvern Panalytival製 型番:ベンチトップ型X線回折装置 Aeris)で解析したところ、酸化ビスマスと思われるピークが観測された。
11 熱電変換層
11c 熱電変換層の材料
12a 第1面
12b 第2面
13a 第1接合層
13b 第2接合層
13c 第1接合層の材料
13d 第2接合層の材料
14a 第1金属層
14b 第2金属層
14c 第1金属層の材料
14d 第2金属層の材料
100,200 熱電変換モジュール
20a,20b n型の熱電変換素子
21 n型の熱電変換層
22a 第3面
22b 第4面
23a 第3接合層
23b 第4接合層
24a 第3金属層
24b 第4金属層
31,32,33 外部電極
41 第1配線
42 第2配線
50 成形型
51 加圧方向
52 電流
Claims (13)
- P型の熱電変換層と、
第1金属層と、
第2金属層と、
前記熱電変換層の第1面及び前記第1金属層を接合する第1接合層と、
前記熱電変換層の第2面及び前記第2金属層を接合する第2接合層と、
を具備する熱電変換素子であって、
前記熱電変換層は、Mgと、Sb及びBiの少なくとも一方とを含有する合金を主相とし、かつ、炭素を含むP型の熱電変換材料からなり、
前記第1接合層及び前記第2接合層の少なくとも一方は、Al及びSiを含有する、
熱電変換素子。 - 前記熱電変換材料の前記主相は、Mg3(Sb,Bi)2系の合金である、
請求項1に記載の熱電変換素子。 - 前記熱電変換素子において、
前記熱電変換材料の前記主相は、式(1)Mg3―mAxSb2-zBizで表され、
ここで、
Aは、Na、Li、及びAgからなる群より選択される少なくとも1つを含み、
-0.39 ≦ m ≦ 0.42
0 < x ≦ 0.12、
0 ≦ z ≦ 2.0、
によって表される組成を有する、
請求項2に記載の熱電変換素子。 - 0.5 ≦ z < 2.0
である、
請求項3に記載の熱電変換素子。 - 0.001 ≦ x ≦ 0.05である、
請求項3又は4に記載の熱電変換素子。 - 前記熱電変換材料は、下記数式(M2)を満たし、
0.5≦IC/IM 数式(M2)
ここで、
ICは、ラマンスペクトルにおける、前記炭素のピーク強度を表し、
IMは、ラマンスペクトルにおける、Mg3(Sb,Bi)2系の前記合金のピーク強度を表す、
請求項2から5のいずれか一項に記載の熱電変換素子。 - 前記熱電変換材料は、下記数式(M1)を満たし、
0.01at%≦CC≦1.2at% 数式(M1)
ここで、
CCは、前記熱電変換材料における前記炭素の含有割合を表す、
請求項1から6のいずれか一項に記載の熱電変換素子。 - 前記熱電変換素子において、
前記第1接合層及び前記第2接合層の少なくとも一方は、下記数式(M3)を満たし、
0.0at%<SC≦25.0at% 数式(M3)
ここで、
SCは、前記第1接合層及び前記第2接合層の少なくとも一方における、前記Siの含有割合を表す、
請求項1から7のいずれか一項に記載の熱電変換素子。 - 前記熱電変換素子において、
前記第1金属層及び前記第2金属層の少なくとも一方は、Cu又はCu合金を含有する、
請求項1から8のいずれか一項に記載の熱電変換素子。 - p型の熱電変換素子とn型の熱電変換素子とが、電気的に接続されている熱電変換モジュールであって、
前記p型の熱電変換素子は、請求項1から9のいずれか一項に記載の熱電変換素子である熱電変換モジュール。 - 前記n型の熱電変換素子は、
Mgと、Sb及びBiの少なくとも一方とを含有する合金を主相とするn型 の熱電変換材料を具備する、
請求項10に記載の熱電変換モジュール。 - 第1金属層の材料、第1接合層の材料、熱電変換層の材料、第2接合層の材料、及び第2金属層の材料をこの順番で成形型に充填する工程と、
前記成形型の内部に充填された、前記第1金属層の材料、前記第1接合層の材料、前記熱電変換層の材料、前記第2接合層の材料、及び前記第2金属層の材料を、所定の温度で加熱及び加圧して接合し、積層体を得る工程と、
前記成形型から前記積層体を取り出す工程と、を含み、
前記熱電変換層の材料は、Mgと、Sb及びBiの少なくとも一方とを含有する合金及び炭素を含有し、
前記第1接合層の材料及び前記第2接合層の材料は、Al及びSiを含有する、
熱電変換素子の製造方法。 - 前記熱電変換材料の製造方法において、
前記所定の温度は、下記数式(M4)を満たし、
300℃≦t≦500℃ 数式(M4)
ここで、
tは、前記積層体を得るための接合温度を表す、
請求項12に記載の熱電変換素子の製造方法。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202280039632.1A CN117461404A (zh) | 2021-06-08 | 2022-04-12 | 热电转换元件、热电转换模块以及热电转换元件的制造方法 |
JP2023527552A JPWO2022259759A1 (ja) | 2021-06-08 | 2022-04-12 | |
US18/515,335 US20240090332A1 (en) | 2021-06-08 | 2023-11-21 | Thermoelectric conversion element, thermoelectric conversion module, and thermoelectric conversion element producing method |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021095574 | 2021-06-08 | ||
JP2021-095574 | 2021-06-08 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US18/515,335 Continuation US20240090332A1 (en) | 2021-06-08 | 2023-11-21 | Thermoelectric conversion element, thermoelectric conversion module, and thermoelectric conversion element producing method |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2022259759A1 true WO2022259759A1 (ja) | 2022-12-15 |
Family
ID=84425888
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2022/017564 WO2022259759A1 (ja) | 2021-06-08 | 2022-04-12 | 熱電変換素子、熱電変換モジュール、及び、熱電変換素子の製造方法 |
Country Status (4)
Country | Link |
---|---|
US (1) | US20240090332A1 (ja) |
JP (1) | JPWO2022259759A1 (ja) |
CN (1) | CN117461404A (ja) |
WO (1) | WO2022259759A1 (ja) |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6225550B1 (en) * | 1999-09-09 | 2001-05-01 | Symyx Technologies, Inc. | Thermoelectric material system |
KR20030092692A (ko) * | 2002-05-30 | 2003-12-06 | 이지환 | 열전소자와 전극이 일체화된 열전재료의 제조 방법 |
JP2004119833A (ja) * | 2002-09-27 | 2004-04-15 | Toshiba Corp | 熱電素子モジュール及びその製造方法 |
JP2005093532A (ja) * | 2003-09-12 | 2005-04-07 | Toshiba Corp | 熱電素子モジュール |
US20160326615A1 (en) * | 2014-02-18 | 2016-11-10 | University Of Houston System | THERMOELECTRIC COMPOSITIONS AND METHODS OF FABRICATING HIGH THERMOELECTRIC PERFORMANCE MgAgSb-BASED MATERIALS |
WO2017072982A1 (ja) * | 2015-10-27 | 2017-05-04 | パナソニックIpマネジメント株式会社 | 熱電変換材料 |
JP2019207983A (ja) * | 2018-05-30 | 2019-12-05 | パナソニックIpマネジメント株式会社 | 熱電変換材料及びこれを用いた熱電変換素子 |
WO2020003554A1 (ja) * | 2018-06-27 | 2020-01-02 | パナソニックIpマネジメント株式会社 | 熱電変換素子及び熱電変換モジュール |
-
2022
- 2022-04-12 WO PCT/JP2022/017564 patent/WO2022259759A1/ja active Application Filing
- 2022-04-12 CN CN202280039632.1A patent/CN117461404A/zh active Pending
- 2022-04-12 JP JP2023527552A patent/JPWO2022259759A1/ja active Pending
-
2023
- 2023-11-21 US US18/515,335 patent/US20240090332A1/en active Pending
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6225550B1 (en) * | 1999-09-09 | 2001-05-01 | Symyx Technologies, Inc. | Thermoelectric material system |
KR20030092692A (ko) * | 2002-05-30 | 2003-12-06 | 이지환 | 열전소자와 전극이 일체화된 열전재료의 제조 방법 |
JP2004119833A (ja) * | 2002-09-27 | 2004-04-15 | Toshiba Corp | 熱電素子モジュール及びその製造方法 |
JP2005093532A (ja) * | 2003-09-12 | 2005-04-07 | Toshiba Corp | 熱電素子モジュール |
US20160326615A1 (en) * | 2014-02-18 | 2016-11-10 | University Of Houston System | THERMOELECTRIC COMPOSITIONS AND METHODS OF FABRICATING HIGH THERMOELECTRIC PERFORMANCE MgAgSb-BASED MATERIALS |
WO2017072982A1 (ja) * | 2015-10-27 | 2017-05-04 | パナソニックIpマネジメント株式会社 | 熱電変換材料 |
JP2019207983A (ja) * | 2018-05-30 | 2019-12-05 | パナソニックIpマネジメント株式会社 | 熱電変換材料及びこれを用いた熱電変換素子 |
WO2020003554A1 (ja) * | 2018-06-27 | 2020-01-02 | パナソニックIpマネジメント株式会社 | 熱電変換素子及び熱電変換モジュール |
Also Published As
Publication number | Publication date |
---|---|
JPWO2022259759A1 (ja) | 2022-12-15 |
CN117461404A (zh) | 2024-01-26 |
US20240090332A1 (en) | 2024-03-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Tan et al. | Rapid preparation of CeFe 4 Sb 12 skutterudite by melt spinning: rich nanostructures and high thermoelectric performance | |
EP2255906B1 (en) | Fabrication of high performance densified nanocrystalline bulk thermoelectric materials using high pressure sintering technique | |
JP5206768B2 (ja) | ナノコンポジット熱電変換材料、その製造方法および熱電変換素子 | |
WO2017072982A1 (ja) | 熱電変換材料 | |
TWI775887B (zh) | 熱電轉換材料、熱電轉換元件、熱電轉換模組及熱電轉換材料之製造方法 | |
US11114600B2 (en) | Polycrystalline magnesium silicide and use thereof | |
KR102165812B1 (ko) | 파마티나이트계 열전재료의 제조방법 | |
WO2007034632A1 (ja) | 熱電変換材料及びその製造方法 | |
EP2913857B1 (en) | Mg-Si THERMOELECTRIC CONVERSION MATERIAL, METHOD FOR PRODUCING SAME, SINTERED BODY FOR THERMOELECTRIC CONVERSION, THERMOELECTRIC CONVERSION ELEMENT, AND THERMOELECTRIC CONVERSION MODULE | |
JP4854215B2 (ja) | 熱電材料とその製造方法 | |
JP6176885B2 (ja) | p型熱電材料、熱電素子およびp型熱電材料の製造方法 | |
KR101631858B1 (ko) | 침입형 도핑재 첨가에 의해 복합결정구조가 형성된 Te계 열전재료 | |
WO2022259759A1 (ja) | 熱電変換素子、熱電変換モジュール、及び、熱電変換素子の製造方法 | |
WO2021131408A1 (ja) | 熱電変換素子、熱電変換モジュール、接合材、熱電変換素子を製造する方法 | |
US11889761B2 (en) | Thermoelectric conversion module member, thermoelectric conversion module, and method for manufacturing thermoelectric conversion module member | |
CN108695429B (zh) | 热电转换材料及其制造方法 | |
WO2019004373A1 (ja) | 熱電変換材料、熱電変換素子、熱電変換モジュール、及び、熱電変換材料の製造方法 | |
WO2021205803A1 (ja) | 熱電変換素子、熱電変換モジュール、接合材、及び熱電変換素子を製造する方法 | |
JP2016092174A (ja) | 熱電変換材料および熱電変換モジュール | |
WO2022259758A1 (ja) | 熱電変換材料、熱電変換材料用組成物、熱電変換素子、熱電変換モジュール、及び熱電変換材料の製造方法 | |
JP2019125676A (ja) | 多結晶性マグネシウムシリサイド及びその利用 | |
WO2023145339A1 (ja) | 熱電変換材料、熱電変換材料用組成物、熱電変換素子、熱電変換モジュール、熱電変換システム、熱電変換材料用組成物の製造方法、及び熱電変換材料の製造方法 | |
WO2023145338A1 (ja) | 熱電変換材料、熱電変換材料用組成物、熱電変換素子、熱電変換モジュール、熱電変換システム、熱電変換材料用組成物の製造方法、及び熱電変換材料の製造方法 | |
Mishra | Half-Heusler based multicomponent alloys for high temperature thermoelectric applications | |
JP6192015B2 (ja) | 熱電変換材料用圧粉体および焼結成形体とその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22819946 Country of ref document: EP Kind code of ref document: A1 |
|
DPE1 | Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2023527552 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202280039632.1 Country of ref document: CN |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 22819946 Country of ref document: EP Kind code of ref document: A1 |