JP2005277120A - Thermoelectric conversion module and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an unprecedented high efficiency from a heat source in an intermediate temperature range such as exhaust heat from a distributed power source using a gas turbine or a gas engine, exhaust gas from a waste incineration facility, automobile exhaust gas, etc. A thermoelectric conversion module that converts heat into electricity is provided.
In the thermoelectric conversion module of the present invention, the p-type thermoelectric element and the n-type thermoelectric element are alternately arranged in a plurality of through holes provided in a mold, and are electrically connected in series by a copper spray electrode. A connected thermoelectric conversion module, wherein the p-type thermoelectric element is mainly composed of zinc and antimony and has a β-type crystal structure, and the n-type thermoelectric element is mainly composed of cobalt and antimony; Thermal spraying composed of molybdenum or tungsten between the p-type thermoelectric element and the n-type thermoelectric element and the copper spray electrode, made of a material having a filled skutterudite structure in which a part of the crystal void is filled. Has a layer.
[Selection] Figure 1

Description

  The present invention relates to a thermoelectric conversion module that directly converts heat into electricity and a method for manufacturing the same, and is particularly useful in a thermoelectric power generation apparatus that uses exhaust heat in an intermediate temperature range as a heat source.

  A thermoelectric conversion module is usually produced by alternately arranging a plurality of p-type thermoelectric elements and n-type thermoelectric elements and electrically connecting these thermoelectric elements in series via a conductive material such as metal. The This thermoelectric conversion module generates a thermoelectromotive force due to the Seebeck effect by giving a temperature difference to the thermoelectric element, and a part of the heat can be converted into electric power and taken out by connecting an electric load. This power generation device using a thermoelectric conversion module is simple in structure, has no moving parts that generate vibration, noise, wear, etc., and has the characteristics that the scale of the heat source is not selected. It has been attracting attention as a means for recovering and effectively using heat as electric power.

  There are various types of heat sources that can be converted into thermoelectric conversion, but heat sources in the middle temperature range include exhaust heat from distributed power sources using gas turbines and gas engines, exhaust gas from waste incinerators, and exhaust gas from automobiles. Etc. Conventionally, in this medium temperature range, PbTe is used as a representative thermoelectric material, and has been used for solar exploration satellites.

  However, PbTe, which exerted its power in outer space, has a major problem of deterioration due to oxidation. To use it on the ground, it is essential to enclose the entire thermoelectric conversion module in a metal capsule together with an inert gas, which is extremely easy to use. Unfortunately, the PbTe module has not been put into practical use as a thermoelectric conversion module that can be generally used because the performance of the material itself does not reach that of Bi-Te materials used in a low temperature region.

  An example of using a Co—Sb-based material for both a p-type thermoelectric element and an n-type thermoelectric element has been reported (see Patent Document 1), but the reported p-type Co—Sb-based material has dimensionless performance. An index of about 1.2 is not sufficient, and a thermoelectric conversion module incorporating these is a module for a low temperature region from room temperature to 200 ° C.

  In addition, as a characteristic in the middle and high temperature region of the Co—Sb material, it is described in the example of Patent Document 2 that the dimensionless figure of merit at 700 K of the Co—Sb material is 1.0 even at the highest value. Has been. Even if two types of Co-Sb-based materials having such performances are combined as a p-type thermoelectric element and an n-type thermoelectric element, the thermoelectric conversion characteristics are not sufficient, and a practical thermoelectric conversion module for a medium to high temperature region is obtained. It is not possible.

JP 2003-218410 A JP 2002-026400 A

  As described above, practical thermoelectric conversion modules that use medium-temperature region heat sources are virtually nonexistent, and the emergence of thermoelectric conversion modules that effectively use medium-temperature region heat sources is awaited. . Accordingly, the object of the present invention is higher than in the past from heat sources in the middle temperature range, such as exhaust heat from distributed power sources utilizing gas turbines, gas engines, etc., exhaust gas from waste incineration facilities, automobile exhaust gas, etc. It is to provide a thermoelectric conversion module that converts heat into electricity with efficiency.

  The present invention comprises a mold provided with a plurality of through holes and a plurality of electrode grooves connecting between the adjacent through holes, a p-type thermoelectric element and an n-type thermoelectric element, and the p-type thermoelectric element And n-type thermoelectric elements are alternately arranged in the plurality of through holes, and a copper spray electrode is embedded in the electrode groove so as to electrically connect the p-type thermoelectric element and the n-type thermoelectric element in series. The p-type thermoelectric element is mainly composed of zinc and antimony and has a β-type crystal structure, and the n-type thermoelectric element is mainly composed of cobalt and antimony and contains a rare earth element. A sprayed layer made of molybdenum or tungsten is formed between the p-type thermoelectric element and the n-type thermoelectric element and the copper spray electrode, and is made of a material having a filled skutterudite structure filled in a part of the crystal void. Having thermoelectric conversion It relates to the Joule.

  Further, the present invention comprises a material having zinc and antimony as main components and a β-type crystal structure in a through-hole of a mold provided with a plurality of through-holes and a plurality of electrode grooves for connecting the through-holes. A p-type thermoelectric element and an n-type thermoelectric element made of a material having a filled skutterudite structure in which cobalt and antimony are main components and a rare earth element is filled in a part of a crystal gap are alternately installed. And spraying molybdenum or tungsten on the surface of the p-type thermoelectric element and the n-type thermoelectric element to form a sprayed layer, and then the p-type thermoelectric element and the n-type thermoelectric element are alternately electrically connected in series. Further, the present invention relates to the method for manufacturing the thermoelectric conversion module, wherein the electrode groove and the copper spray electrode are formed on the electrode groove and the sprayed layer by thermal spraying.

  The thermoelectric conversion module of the present invention uses a p-type thermoelectric element mainly composed of zinc and antimony and an n-type thermoelectric element mainly composed of cobalt and antimony, and has an adjacent p-type thermoelectric element and n-type thermoelectric element. By using a copper sprayed electrode as the thermal spraying electrode for connecting the p-type thermoelectric element and a structure in which a thermal spray layer of molybdenum or tungsten is formed between the p-type thermoelectric element and the n-type thermoelectric element and the copper sprayed electrode, high thermoelectric characteristics In addition, it was possible to form a thermal spray electrode that could not be formed by a conventional method, and for the first time, a practical thermoelectric conversion module using a medium temperature region as a heat source could be provided.

  Hereinafter, the thermoelectric conversion module of the present invention will be described with reference to the drawings.

  FIG. 1 is a high temperature side sketch showing an example of the thermoelectric conversion module of the present invention. FIG. 1 (a) is a plan view of the thermoelectric conversion module of the present invention on the low temperature surface side, FIG. 1 (b) is a cross-sectional view taken along the line AA ′, and FIG. FIG. As shown in FIG. 1, the thermoelectric conversion module 10 of the present embodiment is an electrically and thermally insulating type provided with a plurality of through holes 12 and a plurality of electrode grooves 13 connecting the adjacent through holes 12. A frame 11, a p-type thermoelectric element 14, and an n-type thermoelectric element 15. The p-type thermoelectric element 14 and the n-type thermoelectric element 15 are alternately arranged in the plurality of through holes 12, and the p-type thermoelectric element A copper spray electrode 17 is embedded in the electrode groove 13 so that 14 and the n-type thermoelectric element 15 are electrically connected in series. The mold 11 is made of an electrically and thermally insulating material. The p-type thermoelectric element 14 is made of a material having zinc and antimony as main components and having a β-type crystal structure, and the n-type thermoelectric element 15 is mainly composed of cobalt and antimony, and a rare earth element is included in a part of the crystal void. It consists of a filled material with a filled skutterudite structure. Furthermore, the thermoelectric conversion module 10 of the present invention is characterized by having a thermal spray layer (underlayer) 16 made of molybdenum or tungsten between the p-type thermoelectric element 14 and the n-type thermoelectric element 15 and the copper spray electrode 17. . The p-type thermoelectric element 14 and the n-type thermoelectric element 15, the molybdenum or tungsten sprayed layer (underlayer) 16, and the copper sprayed electrode 17 are integrally fixed to the mold 11.

  There are two preferred forms of the molybdenum or tungsten sprayed layer (underlayer) 16. One form is a form in which the thickness of the molybdenum or tungsten sprayed layer is limited. The preferable thickness of the sprayed layer made of molybdenum or tungsten is 5 to 50 μm, more preferably 30 to 50 μm. By limiting the thickness of the sprayed layer, there is little stress concentration that causes destruction of the thermoelectric element, and there is no element cracking. Therefore, it can manufacture stably and a yield improves.

  Examples of the method for forming the molybdenum or tungsten sprayed layer (underlayer) 16 include general plasma spraying, gas spraying, arc spraying, and high-speed flame spraying, and plasma spraying is particularly preferable. At this time, in order to obtain a thin sprayed layer of molybdenum or tungsten having a thickness of 5 to 50 μm, the amount of powder supplied at the time of spraying may be reduced or the number of spraying passes may be adjusted appropriately.

  Another preferred form of the molybdenum or tungsten sprayed layer (underlayer) 16 is a form in which the coverage on the p-type thermoelectric element 14 and the n-type thermoelectric element 15 is limited. A form in which the coverage of the molybdenum or tungsten sprayed layer (underlayer) 16 on the p-type thermoelectric element 14 and the n-type thermoelectric element 15 is 50 to 95%, preferably 70 to 90%. As in the case where the thickness of the sprayed layer (underlayer) 16 is limited, the stress concentration causing the destruction of the thermoelectric element is small and the element is not cracked. Therefore, it can manufacture stably and a yield improves. Examples of a method for obtaining a mottled molybdenum or tungsten sprayed layer include a method of vibrating the spraying device during spraying, a method of intermittently supplying powder, a method of using a net-like filter between the spraying device and the object to be sprayed, and the like. However, a method using a mesh filter is preferable from the viewpoint of reproducibility. The molybdenum or tungsten sprayed layer preferably has a thickness of 200 μm or less excluding the voids.

  The copper spray electrode 17 can be formed by a general method such as plasma spraying, gas spraying, arc spraying, flame spraying, etc. In order to obtain a dense and uniform electrode, plasma spraying and gas spraying can be performed. It is desirable to form by a method. The copper sprayed layer constituting the copper sprayed electrode 16 preferably has a porosity of 30% or less, particularly 20% or less (see FIG. 2). Since the copper sprayed electrode is composed of a copper sprayed layer having a porosity of 30% or less, the electrode structure has a dense and excellent electrical conductivity, and the power generation performance is improved.

  Further, as the electrically and thermally insulating mold 11, a mold made of a calcium silicate molded body can be used. Calcium silicate has crystal phases called zonotlite and tobermorite, and those formed by mixing an organic binder into these are called artificial wood. This artificial wood has features such as non-combustibility, low thermal conductivity, light weight, and good workability, and thus is suitable as an insulating form for a thermoelectric conversion module. For example, in terms of thermal conductivity, compared with the general lead glass having 1.2 W / mK, the molded body of calcium silicate is 0.08 W / mK, which is as small as 1/15. Even compared with 0.4 W / mK of polyimide which is a heat resistant resin, it is as small as about 1/5. Moreover, in terms of specific gravity, lead glass and polyimide are as small as about 0.5 compared to 3.0 and 1.4, respectively, which is desirable as an insulating form material for a thermoelectric conversion module.

  The thermoelectric material used as the p-type thermoelectric element 14 is made of a material mainly composed of zinc and antimony and having a β-type crystal structure. The thermoelectric material used as the n-type thermoelectric element 15 is a material having a filled skutterudite structure in which cobalt and antimony are the main components and a rare earth element is filled in a part of a crystal void.

  The thermoelectric conversion module of the present invention having the above-described configuration is applied to a thermoelectric power generation system using a heat source in an intermediate temperature region such as exhaust heat from a power plant, waste heat from a garbage incineration facility, exhaust heat from an automobile, sunlight, etc. Is possible.

  Next, the manufacturing method of the thermoelectric conversion module of the present invention will be described with reference to FIG. 3 taking the case of manufacturing the thermoelectric conversion module of the embodiment shown in FIG. 1 as an example. First, an electrical and thermal insulating material is used to electrically provide a plurality of through holes 12 and a plurality of electrode grooves 13 communicating between the through holes 12 as shown in FIG. In addition, a thermally insulating form 11 is produced. In the case where calcium silicate is used as the insulating material, a calcium silicate molded body is first manufactured by a manufacturing method described in, for example, Japanese Patent Laid-Open Nos. 62-123053 and 3-3635. The insulating mold 11 may be produced by machining the molded body.

  Next, as shown in FIG. 3B, p-type thermoelectric elements 14 and n-type thermoelectric elements 15 are alternately arranged in the through holes 12 of the insulating mold 11 using element spacers 18 and 19. .

  Next, the element spacers 18 and 19 are removed, and as shown in FIG. 3C, molybdenum or tungsten sprayed layers (underlying layers) 16 are formed on both surfaces of the p-type thermoelectric element 14 and the n-type thermoelectric element 15 by plasma spraying or the like. Form. At this time, the molybdenum or tungsten underlayer 16 is a thin sprayed layer having a thickness of 5 to 50 μm or a patchy sprayed layer having a coverage of 50 to 95% on the p-type thermoelectric element 14 and the n-type thermoelectric element 15. Preferably it is. After the molybdenum or tungsten sprayed layer (underlayer) 16 is formed, the copper sprayed electrode 17 is formed so as to cover both surfaces of the insulating mold 11 using copper.

  Next, as shown in FIG. 3 (d), unnecessary sprayed electrodes formed on the insulating mold 11 other than the electrode grooves 13 are removed by grinding using a surface grinder or the like, as shown in FIG. The thermoelectric conversion module of the embodiment is obtained. When the unnecessary sprayed electrode is ground and removed, the surface of the insulating mold 11 is slightly cut away to ensure the flatness of the electrode surface.

  According to the method for manufacturing a thermoelectric conversion module of the present invention, a thermoelectric conversion module having a large area can be manufactured with a relatively simple process, and a thermoelectric conversion module suitable for a large-scale heat source can be obtained.

  The effects of the present invention will be specifically described with reference to examples.

(Example 1)
In this example, as thermoelectric elements, zinc and antimony are the main components, a p-type thermoelectric element made of a material having a β-type crystal structure, cobalt and antimony are the main components, and rare earth elements are part of the crystal voids. An n-type thermoelectric element made of a material having a filled skutterudite structure, a mold made of a calcium silicate molded body as an insulating mold, and a copper spray electrode with a porosity of 8% as an electrode A molybdenum or tungsten sprayed layer having a thickness of 80 μm was used as the molybdenum or tungsten sprayed layer (underlayer). First, the insulating form 11 shown in FIG.4 and FIG.5 was produced by machining (NC router) using the molded object of calcium silicate [The Ube Industries, Ltd. make, registered trademark; Woody serum]. As described above, the molded body of calcium silicate has characteristics such as non-combustibility, low thermal conductivity, light weight, and good workability, and thus is suitable as an insulating form for a thermoelectric conversion module. The manufacturing method of the molded body of calcium silicate shown here is described in detail in, for example, Japanese Patent Application Laid-Open Nos. 62-123053 and 3-3635. 4A is a plan view of the low-temperature surface side of the insulating mold 11 of the thermoelectric conversion module used in this example, and FIG. 5A is the insulating type of the thermoelectric conversion module. 3 is a plan view of a high temperature surface side of a frame 11. FIG.

In module design, for example, when both p-type and n-type materials are BiTe-based materials, the difference in thermoelectric characteristics is small, and designing with the same element shape hardly poses a problem. However, the thermoelectric conversion material used in the present invention requires a detailed design because the p-type and n-type have greatly different thermoelectric characteristics. That is, the Zn—Sb-based material has a low thermal conductivity of about 0.6 to 0.8 W / mK and an electric conductivity of about 30,000 to 40,000 S / m. On the other hand, the Co—Sb-based material has a large thermal conductivity of about 3 to 4 W / mK and an electric conductivity of about 60000 to 70000 S / m. Therefore, it is necessary to optimize the temperature difference of each element while adjusting the heat flux flowing through each element, and to adjust and optimize the internal resistance of the module. Roughly speaking, the element diameter of the Co—Sb-based material with high thermal conductivity and large electric conductivity is small, and conversely, the Zn—Sb-based material with small thermal conductivity and small electric conductivity is designed to increase the element diameter. It becomes. The relationship is
(A _n / A _p ) (h _n / h _p ) ⁻¹ = (ρ _n / ρ _p ) ^1/2 (κ _n / κ _p ) ^−1/2
It is expressed. Here _A n, _{h n,} [rho _n, kappa _n, the cross-sectional area of the respective n-type elements, the height, the specific resistance, by the thermal _{conductivity, A p, h p, ρ} p, κ p is p-type, respectively It represents the cross-sectional area, height, specific resistance, and thermal conductivity of the element. The above-described optimization design is detailed in “Thermoelectric Conversion Engineering: Basics and Applications” (published by Realize, 2001).

Next, according to the method described in detail in Japanese Patent Application No. 2002-11454 previously filed by the inventors, a p-type thermoelectric element composed mainly of zinc and antimony and having a β-type crystal structure is as follows. It was prepared. Weighed 84.0396 g of Zn powder (Rare Metallic, purity 99.99%, particle size 10-30 mesh) and 115.604 g of Sb powder (Rare Metallic, purity 99.99%, particle size 10-30 mesh). Three powder samples were prepared in which Zn was 0.3 at% richer than the stoichiometric composition. For each powder sample, Pb was weighed to a molar ratio of 3% with respect to β-Zn ₄ Sb ₃ (eg, 3 mol of Pb with respect to 100 mol of β-Zn ₄ Sb ₃ ), Added to each powder sample and mixed. These were sealed by introducing an inert gas into an ampule tube. This ampule tube was set in a melting and stirring furnace, and a melted β-Zn ₄ Sb ₃ melted material was produced. Next, this melted material was dry-pulverized with a jet mill to prepare a raw material 1 having a particle size of less than 20 μm. Further, the melted material was dry-pulverized with an automatic mortar to prepare a raw material 2 having a particle size of 20 to 200 μm. These raw materials 1 and 2 were dry-mixed in a V blender for 24 hours at a weight ratio of raw material 1: raw material 2 = 1: 15 to obtain a sintered raw material. This sintered raw material was filled in a graphite mold and hot-pressed at 470 ° C. for 300 minutes under a pressure of 40 MPa to obtain a β-Zn ₄ Sb ₃ sintered body. A cylindrical thermoelectric element (9φ × 7 mmh) was produced from the obtained sintered body using a thin cutting machine, an ultrasonic processing machine or the like.

  Next, an n-type thermoelectric element made of a material having a filled skutterudite structure in which cobalt and antimony are main components and a rare earth element is filled in a part of a void of a crystal was manufactured as follows. First, each raw material was weighed so that the atomic ratio was Yb: Co: Sb = 0.3: 4: 12. Next, these raw materials were vacuum-sealed in a glass tube and melted and stirred at 1100 ° C. for 1 hour to produce a material thermoelectric material having a filled skutterudite structure. These thermoelectric materials were pulverized with a stamp mill and a ball mill to an average particle size of about 10 μm. The obtained thermoelectric material powder was sintered at 700 ° C. for 300 minutes using a hot press to obtain a sintered body of thermoelectric material. A cylindrical thermoelectric element (5.2φ × 7 mmh) was produced from the obtained sintered body using a thin cutting machine, an ultrasonic processing machine or the like.

  About each material obtained by the above, what measured the temperature change of Seebeck coefficient, electrical conductivity, and thermal conductivity, and computed the figure of merit was plotted in FIG. For reference, the dimensionless figure of merit of p-type and n-type BiTe materials is also plotted.

  Next, the p-type thermoelectric element 14 and the n-type thermoelectric element 15 are sandblasted to roughen the surface, and then alternately formed into insulating molds using element spacers 18 and 19 as shown in FIG. Arranged. Next, as shown in FIG. 3C, a molybdenum underlayer 16 having a thickness of 80 μm is formed by plasma spraying in order to improve the adhesion strength between the thermoelectric element and the copper electrode, and then a copper sprayed electrode 17 is formed thereon by about 2 mm. did. At this time, the copper sprayed layer constituting the copper sprayed electrode had a structure having a gap of about 5 to 18%, depending on the field of view, when the section was observed with a microscope and the porosity was calculated. The molybdenum underlayer on the back surface and the copper sprayed electrode were formed in the same manner. However, the element spacer is not necessary when spraying the back surface.

  Next, as shown in FIG.3 (d), the unnecessary part was ground for the copper sprayed electrode 16 formed in both surfaces of the insulating formwork 11 using the surface grinder, and the thermoelectric conversion module 10 was produced. At this time, in order to ensure the flatness of the electrode surface, the insulating mold was also slightly cut. Since the obtained thermoelectric conversion module does not generate an effective electromotive force for each pair of current extraction lead wire portions, the substantial number of elements is 31 pairs. FIG. 7 shows a photograph of the appearance of the thermoelectric conversion module thus manufactured.

  The thermoelectric conversion module (31 pairs of elements, module size 86 × 86 × 10 mm) manufactured as described above is sandwiched between an electric heater and a cooling plate, and the low temperature surface is set to 230 ° C. and the high temperature surface is set to 450 ° C. The power generation characteristics were evaluated by applying a temperature difference of. An electronic load device was used for the measurement, and the load resistance was measured at 0.35Ω. At this time, the maximum electric output of 5.73 W could be generated with one thermoelectric conversion module.

(Example 2)
When forming the molybdenum base layer by plasma spraying, use a mesh filter between the thermal spraying device and the object to be sprayed, except that the base layer has a patchy structure (coverage 80%) with a thickness of 50 to 150 μm. A thermoelectric conversion module was produced in the same manner as in Example 1. One thermoelectric conversion module produced in this way was able to generate a maximum electrical output of 5.68 W.

(Example 3)
A thermoelectric conversion module was produced by the same process as in Example 1 except that a tungsten layer of about 80 μm was formed by plasma spraying as the underlayer. One thermoelectric conversion module manufactured in this way was able to generate a maximum electrical output of 5.47 W.

Example 4
When forming the tungsten underlayer by plasma spraying, use a net-like filter between the spraying device and the object to be sprayed, except that the underlayer has a spot-like structure (coverage 80%) with a thickness of 50 to 150 μm. A thermoelectric conversion module was produced in the same manner as in Example 3. A single thermoelectric conversion module manufactured in this way was able to generate a maximum electrical output of 5.32W.

(Comparative Example 1)
As an underlayer, except that a nickel layer of about 80 μm was formed by plasma spraying, an attempt was made to produce a thermoelectric conversion module by the same process as in Example 1. After forming the nickel underlayer, a copper electrode was being formed. Thus, the electrode peeled before reaching the predetermined thickness. Subsequently, various thermal spraying conditions were examined, but electrode peeling during the process could not be prevented under any of the attempted conditions.

(Comparative Example 2)
As an underlayer, except that a chromium layer of about 80 μm was formed by plasma spraying, an attempt was made to produce a thermoelectric conversion module by the same process as in Example 1. After forming the nickel underlayer, a copper electrode was being formed. Thus, the electrode peeled before reaching the predetermined thickness. Subsequently, various thermal spraying conditions were examined, but electrode peeling during the process could not be prevented under any of the attempted conditions.

(Comparative Example 3)
As an underlayer, except that a cobalt layer of about 80 μm was formed by plasma spraying, an attempt was made to produce a thermoelectric conversion module by the same process as in Example 1. After forming the nickel underlayer, a copper electrode was being formed. Thus, the electrode peeled before reaching the predetermined thickness. Subsequently, various thermal spraying conditions were examined, but electrode peeling during the process could not be prevented under any of the attempted conditions.

FIG. 1 is a high temperature side sketch showing an example of the thermoelectric conversion module of the present invention. FIG. 1 (a) is a plan view of the thermoelectric conversion module of the present invention on the low temperature surface side, FIG. 1 (b) is a cross-sectional view taken along the line AA ′, and FIG. FIG. FIG. 2 is a sketch of a low temperature side view showing an example of the thermoelectric conversion module of the present invention. 3A, 3B, 3C and 3D are process diagrams showing an example of a method for manufacturing a thermoelectric conversion module of the present invention. 4A is a plan view on the low temperature surface side of the insulating mold used in the embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along the line AA ′ in FIG. c) is a side view. 5A is a plan view on the high temperature surface side of the insulating mold shown in FIG. 4, FIG. 5B is a cross-sectional view taken along the line BB ′, and FIG. It is CC 'sectional view taken on the line. FIG. 6 is a diagram in which the dimensionless figure of merit of the p-type Zn—Sb-based material and the n-type Co—Sb-based material used in the thermoelectric conversion module described in Example 1 is plotted. FIG. 7 is an appearance photograph of the thermoelectric conversion module described in Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Thermoelectric conversion module 11 Insulating mold 12 Through hole 13 Electrode groove 14 P-type thermoelectric element 15 N-type thermoelectric element 16 Molybdenum or tungsten sprayed layer (underlayer)
17 Copper spray electrode 18, 19 Element spacer

Claims (2)

A mold having a plurality of through holes and a plurality of electrode grooves connecting between the adjacent through holes; a p-type thermoelectric element and an n-type thermoelectric element; and the p-type thermoelectric element and the n-type thermoelectric element. A thermoelectric conversion module in which elements are alternately arranged in the plurality of through holes, and a copper spray electrode is embedded in the electrode groove so that the p-type thermoelectric element and the n-type thermoelectric element are electrically connected in series. And the p-type thermoelectric element is composed of a material having zinc and antimony as main components and having a β-type crystal structure, and the n-type thermoelectric element is mainly composed of cobalt and antimony, and a rare earth element having a void in the crystal. A partially filled material having a filled skutterudite structure, and having a thermal spray layer made of molybdenum or tungsten between the p-type thermoelectric element and the n-type thermoelectric element and the copper spray electrode. Heat Conversion module. A p-type thermoelectric element made of a material having a β-type crystal structure, the main component of which is zinc and antimony, in a through-hole of a mold provided with a plurality of through-holes and a plurality of electrode grooves connecting between the through-holes; The p-type thermoelectric elements are alternately arranged with n-type thermoelectric elements made of a material having a filled skutterudite structure in which cobalt and antimony are the main components and a rare earth element is filled in a part of a crystal void. And thermally spraying molybdenum or tungsten on the surface of the n-type thermoelectric element to form a sprayed layer, and then the electrode groove and the p-type thermoelectric element and the n-type thermoelectric element are alternately connected in series. The method for manufacturing a thermoelectric conversion module according to claim 1, wherein the copper groove spray electrode is formed on the sprayed layer by thermal spraying.

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