JP2006086512A - Thermoelectric conversion system using filled skutterudite alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a filled skutterudite alloy which can be used in a thermoelectric conversion element as it is without requiring a pulverizing and sintering step of a metal, to provide the alloy suitable for the thermoelectric conversion element manufactured by the method, and to provide a power generation system with high efficiency. <P>SOLUTION: The method for manufacturing the filled skutterudite alloy comprises melting a raw material for the alloy comprising a rare earth metal R (wherein R is at least one of La, Ce, Pr, Nd, Sm, Eu and Yb), and a transition metal T, (wherein T is at least one of Fe, Co, Ni, Os, Ru, Pd, Pt and Ag) and metallic antimony (Sb), and rapidly solidifying the molten metal with a strip cast method, and a thermoelectric conversion module is thereby manufactured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a thermoelectric power generation apparatus and a thermoelectric power generation method using a thermoelectric conversion element, and more particularly to a thermoelectric conversion system using a filled skutterudite-based alloy used for a thermoelectric conversion element that directly converts heat into electricity by the Seebeck effect.

A thermoelectric conversion material made of a filled skutterudite-based alloy has a thermal conductivity higher than that of an intermetallic compound such as CoSb ₃ having a skutterudite-type crystal structure, which is one of the conventional thermoelectric conversion materials. Therefore, it is promising as a thermoelectric conversion material particularly in a high temperature range.

The filled skutterudite-based alloy is an intermetallic compound represented by the general formula RT ₄ Pn ₁₂ (where R is a rare earth metal, T is a transition metal, and Pn is an element such as P, As, or Sb). The mass of a rare earth metal (R) or the like in part of the vacancies present in the crystal of the skutterudite structure represented by the formula TPn ₃ (where T is a transition metal, Pn is an element such as P, As, or Sb) Filled with large atoms. By filling rare earth metal atoms in the vacancies of the crystal of the skutterudite structure, the rare earth metal atoms vibrate due to the weak bond with Pn. It is described that the conversion material has a low thermal conductivity.

In addition, it is considered that filled skutterudite-based alloys can be made to be both p-type and n-type by appropriately selecting R or T. Therefore, in order to control the p-type and n-type, an attempt has been made to replace a part of the T component made of Fe with Co, Ni, or the like.

The block-shaped p-type and n-type filled skutterudite-based alloys produced as described above are joined directly or indirectly via a metal conductor to form a pn junction, thereby forming a thermoelectric conversion element. Can be produced. Alternatively, a thermoelectric conversion material made of a p-type and n-type filled skutterudite-based alloy is brought into contact with a horseshoe shape to produce a pn junction, and a module of a thermoelectric conversion element can be produced. Further, a thermoelectric conversion system is formed by connecting a plurality of thermoelectric conversion elements having a pn junction and joining a heat exchanger, and can extract electricity from a temperature difference.
JP 2000-252526 A JP 2002-26400 A

Conventionally, in order to produce a thermoelectric conversion element using a filled skutterudite-based alloy, a filled skutterudite alloy intended for high-purity powder raw materials such as rare earth metals, transition metals and P, As, Sb, etc. Weigh and mix so as to have a composition, once calcined at a temperature of 800 ° C. or lower, pulverized again, and then heated to 800 ° C. by hot pressing or plasma discharge sintering to produce a sintered body, which is cut And it was used as an element.

However, in the above method, the crystal grain size of the filled skutterudite alloy greatly depends on the state of the powder raw material. Further, unless the sintering conditions are strictly controlled, there is a problem that the crystal grain size becomes coarse and the performance of the thermoelectric conversion element is deteriorated.

Therefore, for the purpose of preventing the above problems, the sintered body of the Sb-containing skutterudite-based thermoelectric material, which is one of the filled skutterudite-based thermoelectric conversion materials, is composed of crystal grains having a skutterudite structure. In addition, a technique for dispersing a metal oxide at the grain boundaries of the crystal grains has been proposed (Patent Document 1).

According to the above method, it is said that the average crystal grain size of crystal grains having a skutterudite structure can be 20 μm or less. However, this method has a problem that the electrical conductivity is lowered because a metal oxide is present in the crystal grain boundary.

Further, as another method for producing a thermoelectric conversion material made of a filled skutterudite-based alloy, there is a method of heat-treating a ribbon produced by a liquid quenching method (Patent Document 2). In general, the liquid quenching method is a method in which a molten metal is poured onto a roll rotating at high speed from a nozzle having a hole of about 1 mm at the tip of a tube made of quartz.

However, in this method, it is difficult to obtain a filled skutterudite element of sufficient purity because the ribbon contains amorphous or decomposition products such as Sb ₂ Fe and Sb, and heat treatment is not performed for more than 5 hours at 873K to 1073K. There is a problem that it cannot be used.

Furthermore, in any of the above methods, when the steps from raw material preparation to sintering are performed in an atmosphere such as the atmosphere where oxygen is present, rare earth metal atoms in the crystal of the filled skutterudite structure are latticed by oxidation of the rare earth metal. There was a problem that it was removed from the inside and a part of the filled skutterudite structure was decomposed into Sb ₂ Fe and Sb.

This invention solves the problem of the manufacturing method of the conventional filled skutterudite type thermoelectric conversion material by manufacturing a filled skutterudite type alloy by a strip casting method. That is, the present invention provides a method for producing a filled skutterudite-based alloy that can be used as it is for a thermoelectric conversion element as it is without the need to perform metal grinding and sintering steps, and a thermoelectric conversion element produced by the method. A suitable alloy is provided.
Furthermore, the present invention provides a thermoelectric conversion module in which a heat conversion element is made of an alloy consisting only of a filled skutterudite phase and the heat conversion efficiency is greatly increased.

The present invention includes the following inventions.
(1) Rare earth metal R (where R is at least one of La, Ce, Pr, Nd, Sm, Eu, Yb), transition metal T (where T is Fe, Co, Ni, Os, Ru, Thermoelectric conversion using a filled skutterudite-based alloy produced by melting an alloy raw material comprising at least one of Pd, Pt, and Ag) and metal antimony (Sb) and rapidly solidifying the molten metal by strip casting. module.
(2) A thermoelectric generator using the thermoelectric conversion module according to (1).
(3) A thermoelectric power generation method using the thermoelectric conversion module according to (1).
(4) A waste heat recovery system using the thermoelectric generator according to (2).
(5) A solar heat utilization system using the thermoelectric generator according to (2).

According to the present invention, a substantially uniform filled skutterudite-based alloy can be easily produced in large quantities by a casting method using a strip casting method. Moreover, since the filled skutterudite-based alloy produced by the production method of the present invention can be used as it is for a thermoelectric conversion element by omitting the pulverization and sintering steps, the production cost of the thermoelectric conversion element is greatly increased. Can be reduced.
Among rare earth metals, La, which has few resource constraints, uses not only high industrial utility value but also metals that do not contain harmful substances (Pb (lead), Te (tellurium), etc. In addition, the filled skutterudite-based alloy of the present invention exhibits high performance in a high temperature range of 300 ° C. or higher, and therefore generates a large amount of power. By combining the casting method and grinding / sintering technology, the element can be made from an alloy consisting only of the filled skutterudite phase, which is a high-performance component, achieving performance equivalent to or better than the conventional Pb-Te system. It is possible to achieve both a high Seebeck coefficient and a low electrical resistance, and the thermoelectric conversion module can be made compact because of its low thermal conductivity.

Moreover, since the thermoelectric conversion module which is a preferred embodiment of the present invention can be used up to a high temperature region of 700 ° C., when incorporated in a waste heat utilization system, the amount of heat that can be recovered by a heat exchanger can be increased. Therefore, the amount of unused heat can be reduced. That is, since it is possible to reduce the heat thrown away to lower the operating temperature, the heat conversion efficiency is greatly improved and the amount of power generation is significantly increased.
When incorporated in a cogeneration system, it is possible to convert heat (unnecessary hot water) that cannot be used into electricity, so the amount of power generation that can improve fuel efficiency increases, and contributes to higher power generation efficiency as the heart of thermoelectric power generation modules. Is possible.
By adopting the production process established in the production of rare earth sintered magnets, mass production at an industrial scale and low cost is easier compared to conventional batch production methods.
The high-performance thermoelectric element produced by the present invention is not only a large-scale waste heat including various industrial furnaces and incinerators, but also natural energy such as various cogeneration, hot water heaters, automobile exhaust gas, geothermal heat and solar heat. As a heart component of a thermoelectric power generation module that converts waste heat that is small but not used into electricity as a heat source, it is possible to contribute to high efficiency of power generation, and it is very effective for global warming countermeasures.

The filled skutterudite-based alloy according to the present invention has a general formula of RT ₄ Sb ₁₂ (where R is at least one of La, Ce, Pr, Nd, Sm, Eu, and Yb, and T is Fe, Co, This is an alloy in which the filled skutterudite phase represented by Ni, Os, Ru, Pd, Pt, and Ag) occupies 95% or more by volume ratio. A part of Sb may be substituted with As or P.

As a raw material for the filled skutterudite-based alloy of the present invention, the rare earth metal R is a rare earth metal (purity of 90% by mass or more, the balance being inevitable impurities such as Al, Fe, Mo, W, C, O, N) or Ce, La A misch metal (90% by mass or more of rare earth metal component, the balance being inevitable impurities such as Al, Fe, Mo, W, C, O, and N) can be used. As the transition metal T, pure iron (purity 99% by mass or more) or metal such as Co or Ni (purity 99% by mass or more) can be used. Further, as Sb, metal antimony (purity of 95% by mass or more and the balance is inevitable impurities such as Pb, As, Fe, Cu, Bi, Ni, C, O, and N) can be used. The raw material of the filled skutterudite-based alloy of the present invention is adjusted by weighing these R, T and metal antimony raw materials so that the alloy composition is RT ₄ Sb ₁₂ . In order to produce the alloy of the present invention, the composition ratios of raw materials R, T, and Sb are 7.5 to 8.3 mass%, 12.1 to 12.3 mass%, and 79.5 to 80.2 mass, respectively. % Range is preferable

In the present invention, a filled skutterudite-based alloy is manufactured by a strip casting method (SC method). FIG. 1 shows a manufacturing apparatus of the SC method used for manufacturing an alloy. In FIG. 1, 1 is a crucible, 2 is a tundish, 3 is a copper roll, 4 is a collection box, 5 is a molten metal, and 6 is a thin piece of solidified alloy.

In the method for producing a filled skutterudite alloy of the present invention, the alloy raw material prepared as described above is melted in the crucible 1 at a temperature of 800 to 1800 ° C. in an inert gas atmosphere such as Ar or He. . At this time, it is preferable to set the atmospheric pressure in a range greater than atmospheric pressure (0.1 MPa) and 0.2 MPa or less because the amount of Sb evaporation can be suppressed.

The molten metal 5 in which the alloy raw material has been melted is rapidly solidified by pouring on the water-cooled copper roll 3 rotating in the direction of the arrow in FIG. The cooling rate at this time is preferably 10 ² to 10 ⁴ ° C./second in the range from the temperature of the molten metal to 800 ° C., which is preferable for obtaining a uniform alloy structure in the filled skutterudite phase. More preferably, it is ^{2 to} 3 × 10 ³ ° C./second. The cooling rate of the molten metal can be controlled to a desired value by controlling the peripheral speed of the copper roll 3 or the amount of molten metal poured into the copper roll 3.

The alloy solidified by the molten metal is peeled off from the copper roll 3 to become a thin piece 6 and is collected in the collection box 4. And it cools to room temperature in the collection box 4, and is taken out. Here, the cooling rate of the alloy flakes after solidification can be controlled by thermally insulating or forcibly cooling the collection box 4. By controlling the cooling rate of the alloy flakes thus solidified, the uniformity of the filled skutterudite phase in the alloy can be further improved.

The thickness of the flake skutterudite-based alloy flake produced by the SC method in the present invention is preferably 0.1 to 2 mm. By setting the thickness of the alloy piece to 0.1 to 2 mm, a filled skutterudite-based alloy that has sufficient mechanical strength and can be easily processed when used in a thermoelectric conversion element can be obtained.

The filled skutterudite-based alloy produced as described above in the present invention can be identified by a powder X-ray diffraction method without performing a new heat treatment in a state of being taken out from the SC method manufacturing apparatus. The intensity ratio of the strongest peak of the filled skutterudite phase is 95% or more. An example in which the formation phase of the filled skutterudite alloy of the present invention is identified by a powder X-ray diffraction method is shown in FIG.

FIG. 2 is a diagram showing the results of X-ray diffraction measurement obtained by pulverizing and measuring an alloy as taken out from the SC method manufacturing apparatus. The integrated intensity of the peak indicating the highest intensity of the filled skutterudite phase and the integrated intensity of the peak indicating the highest intensity of other phases such as Sb ₂ Fe and Sb are calculated, and the ratio between the filled skutterudite phase and the sum of these is calculated. It is possible to know the abundance ratio of the filled skutterudite phase by calculating. For example, in the X-ray diffraction diagram shown in FIG. 2, the abundance ratio of the filled skutterudite phase is 99% by mass or more.

Further, in the filled skutterudite-based alloy produced as described above in the present invention, the filled skutterudite phase accounts for 95% or more by volume, and phases other than the filled skutterudite phase are 5% or less by volume. It is. Here, the phase other than the filled skutterudite phase is, for example, a phase such as Sb ₂ Fe or Sb. Further, in the alloy of the present invention, the maximum diameter of the phase other than the filled skutterudite phase is 10 μm or less.

The volume ratio of the filled skutterudite phase and the phase other than the filled skutterudite phase in the alloy is calculated from the area ratio of the contrast region different from the filled skutterudite phase from the backscattered electron image of the scanning electron microscope. Can be measured. In addition, the maximum diameter of the phase other than the filled skutterudite phase can be determined from the reflected electron image. An example of the backscattered electron image of the filled skutterudite-based alloy of the present invention by a scanning electron microscope is shown in FIG. It can be seen that the alloy is almost uniformly a filled skutterudite phase, the volume ratio is 95% by volume or more, and the maximum diameter of the phases other than the filled skutterudite phase is 10 μm or less.

Further, since the filled skutterudite-based alloy of the present invention is melted and cast in an inert atmosphere, the total content of oxygen, nitrogen and carbon can be made 0.2 mass% or less.

  When producing a thermoelectric conversion element, the filled skutterudite-based alloy obtained in the present invention can be suitably used as a p-type material. As the n-type material, a substance other than the filled skutterudite-based alloy such as an existing Pb—Te-based material can be used. These p-type and n-type thermoelectric conversion materials are bonded directly or indirectly via a metal conductor to form a pn junction, whereby a thermoelectric conversion element can be produced. Moreover, when producing a thermoelectric element module, it can be used in combination with a Bi-Te-based material or Se-based compound having excellent properties at low temperatures and a Co oxide-based compound having excellent properties at high temperatures.

Although the manufacturing method of a thermoelectric conversion element is not specifically limited, A manufacturing process like FIG. 4 can be illustrated.
Although the structure of the thermoelectric conversion module and thermoelectric conversion system which are manufactured from the thermoelectric conversion element which is a preferable embodiment of this invention is not specifically limited, A system like FIG. 5 can be illustrated. For example, the p-type semiconductor and the n-type semiconductor constituting the thermoelectric conversion element are electrically connected in series or in parallel to constitute a thermoelectric conversion module. The high temperature contact portion side of the configured thermoelectric conversion element is in close contact with the waste heat side heat exchanger via an insulator. On the other hand, the low-temperature contact portion side of the thermoelectric conversion element is in close contact with the cooling water side heat exchanger via an insulator.
In the thermoelectric conversion system configured as described above, a temperature difference is generated in each of the p-type semiconductor and the n-type semiconductor connected to the high temperature contact portion side and the low temperature contact portion side, and the temperature difference based on the Seebeck effect is applied. Electricity is generated by thermoelectric conversion.
By adopting the thermoelectric conversion system manufactured by the present invention, not only large-scale waste heat including various industrial furnaces and incinerators, but also various cogeneration, water heaters, automobile exhaust gas, geothermal and solar heat, etc. Natural energy and the like can be used with high efficiency.

Hereinafter, the present invention will be described in more detail with reference to examples.
(Reference Example 1)
La metal was used as the rare earth metal, and electrolytic iron and Sb were weighed so as to correspond to the stoichiometric composition of LaFe ₄ Sb ₁₂ and dissolved in an Ar atmosphere of 0.1 MPa up to 1400 ° C. Thereafter, using the strip cast casting apparatus shown in FIG. 1, the molten metal was poured onto a water-cooled copper roll having a lateral width of 0.92 m / s with a casting amount of 85 mm in width and 150 g / s, and a thickness of 0.28 mm. An alloy flake was prepared. The cooling rate at this time seems to be about 1 × 10 ³ ° C./sec.

When the manufactured alloy flakes were pulverized and subjected to powder X-ray diffraction measurement, Sb2Fe or Sb peaks were hardly observed as shown in FIG. 2, and the abundance ratio of filled skutterudite phase was calculated from this figure. % Or more was LaFe ₄ Sb ₁₂ filled skutterudite phase, and Sb ₂ Fe was 2% or less.

Furthermore, when the alloy flakes were heat-treated at 550 ° C. for 1 hour in an Ar flow at atmospheric pressure, almost 100% of the alloy flakes became LaFe ₄ Sb ₁₂ filled skutterudite phase by powder X-ray diffraction measurement. As a result of confirming the microstructure and the generated phase from the reflected electron image of the heat-treated alloy, no phase separation was observed, and almost the entire alloy was a uniform filled skutterudite phase.

(Reference Example 2)
Ce is 53 wt% as a rare earth metal, La is with 47% by weight of misch metal, Other electrolytic iron, Sb (99%) of _{(Ce x, La 1-x} ) Fe 4 stoichiometry of _{Sb 12} And was dissolved in an Ar atmosphere of 0.1 MPa up to 1400 ° C. Thereafter, using the strip cast casting apparatus shown in FIG. 1, the molten metal was poured onto a water-cooled copper roll having a lateral width of 0.92 m / s with a casting amount of 85 mm in width and 150 g / s, and a thickness of 0.28 mm. An alloy flake was prepared.

The alloy was pulverized and by performing powder X-ray diffraction measurement, a 98% or more at an intensity ratio of the strongest peak _{(Ce x, La 1-x} ) Fe 4 Sb 12 filled skutterudite phase, _Sb 2 Fe Was less than 2%.

Furthermore, if the cooling rate of the recovery box is controlled in an Ar atmosphere at atmospheric pressure from 700 ° C. to 500 ° C. immediately after casting of this alloy in an atmospheric pressure Ar atmosphere, 99% or more (Ce _x , La _1-x ) Fe ₄ Sb ₁₂ filled skutterudite phase. As a result of confirming the microstructure and the generated phase from the reflected electron image of the heat-treated alloy, no phase separation was observed, and the entire alloy was a substantially uniform filled skutterudite phase.

(Reference Example 3)
La metal was used as the rare earth metal, and electrolytic iron and Sb were weighed so as to correspond to the stoichiometric composition of LaFe ₄ Sb ₁₂ and dissolved in an Ar atmosphere at 0.2 MPa up to 1400 ° C. Thereafter, using the strip cast casting apparatus shown in FIG. 1, the molten metal was poured onto a water-cooled copper roll having a lateral width of 0.92 m / s with a casting amount of 85 mm in width and 150 g / s, and a thickness of 0.28 mm. An alloy flake was prepared.

When the produced alloy flakes were pulverized and subjected to powder X-ray diffraction measurement, 95% or more of the strongest peak intensity ratio was LaFe ₄ Sb ₁₂ filled skutterudite phase, and Sb ₂ Fe was 5% or less. .

Furthermore, when the alloy flakes were heat-treated at 550 ° C. for 1 hour in an Ar flow at atmospheric pressure, 99% or more of the alloy flakes became a LaFe ₄ Sb ₁₂ filled skutterudite phase by powder X-ray diffraction measurement. As a result of confirming the microstructure and the generated phase from the reflected electron image of the heat-treated alloy, no phase separation was observed, and the entire alloy was a substantially uniform filled skutterudite phase.

(Example 1)
An alloy described in Reference Example 3 was prepared as a p-type element, and CeCo ₄ Sb ₁₂ was prepared as an n-type element by the same method as in Reference Examples 1 to 3, and a powder having an average particle size of 2.5 μm was produced by jet milling. Molded at a pressure of ² t / cm ² , sintered in an 800 to 900 ° C. argon flow, cut out a 2 mm square element, Cu as an electrode, Ti as a diffusion prevention layer, Ni plating, then Ag brazing at 700 ° C. A laminated module was prepared.

Using this element, a module was produced with 70 pairs of p and n elements, and the conversion efficiency was 13% with respect to heat input at 30 ° C. on the low temperature side and 500 ° C. on the high temperature side.

(Comparative Example 1)
La metal was used as the rare earth metal, and electrolytic iron and Sb were also weighed so as to correspond to the stoichiometric composition of LaFe ₄ Sb ₁₂ and dissolved in a reduced pressure atmosphere of 10 Pa up to 1400 ° C. Further, while maintaining the reduced pressure, in the same manner as in Example 1, the molten metal was poured onto a water-cooled copper roll having a width of 85 mm, a pouring amount of 150 g / s and a peripheral speed of 0.92 m / s, and a thickness of 0.28 mm. A strip cast alloy was prepared.

When this alloy was pulverized and subjected to powder X-ray diffraction measurement, almost all were Sb ₂ Fe and Sb. Further, when the microstructure and the generated phase were confirmed from the reflected electron image of the alloy after the heat treatment, the alloy was composed of a plurality of phases. Further, the oxygen concentration of this alloy exceeded 0.2% by mass, and the amount of Sb was insufficient in stoichiometry. That is, it was speculated that the filled skutterudite phase could not be obtained because the rare earth was removed from the skutterudite phase and Sb evaporated during dissolution and shifted from the stoichiometry.

(Comparative Example 2)
La metal was used as the rare earth metal, and in addition, electrolytic iron and Sb were weighed so as to correspond to the stoichiometric composition of LaFe ₄ Sb ₁₂ and dissolved up to 1400 ° C. in an Ar atmosphere of 0.1 MPa. Thereafter, the molten metal was poured onto a book mold made of a copper plate having a width of 10 mm and a thickness of 20 mm at a pouring amount of 150 g / s to produce an alloy.

When this alloy was pulverized and subjected to powder X-ray diffraction measurement, almost all were Sb2Fe and Sb. Furthermore, when this alloy was heat-treated at 550 ° C. for 1 hour in an Ar atmospheric pressure flow, powder X-ray diffraction measurement still showed almost all Sb ₂ Fe and almost no filled skutterudite phase. Moreover, when the microstructure after heat processing was confirmed about the microstructure and the production | generation phase from the reflected-electron image, the alloy was comprised from the several phase. The oxygen concentration of this alloy was 0.1% by mass or less, and the amount of Sb was almost stoichiometric. However, in order to make this alloy into a uniform filled skutterudite phase, a very long heat treatment was required. So I thought.

(Comparative Example 3)
An alloy for p-type LaFe ₄ Sb ₁₂ and n-type CeCo ₄ Sb ₁₂ elements was produced by the method of Comparative Example 2, and a powder having an average particle size of 2.5 μm was produced by jet milling without heat treatment, 1.2 t / cm Formed at a pressure of ² , sintered in an argon flow of 800 to 900 ° C., cut out a 2 mm square element, Cu as an electrode, Ti as a diffusion prevention layer, Ni plating, and then bonded at 700 ° C. with Ag brazing Was made.

Using this element, a module was fabricated with 70 pairs of p and n elements, and the conversion efficiency was 8% with respect to heat input at 30 ° C. on the low temperature side and 500 ° C. on the high temperature side.

It is a schematic diagram of the strip cast manufacturing apparatus used by this invention. 1 is an X-ray diffraction pattern of a LaFe ₄ Sb ₁₂ filled skutterudite alloy obtained by the present invention. A reflection electron image of a cross section of LaFe ₄ Sb ₁₂ filled skutterudite alloy obtained by the present invention. It is the figure which showed an example of the manufacturing process of the thermoelectric element module for heat_generation | fever. It is the figure which showed an example of the thermoelectric conversion module and the thermoelectric conversion system.

Explanation of symbols

1 crucible 2 tundish 3 copper roll 4 collection box 5 molten metal 6 alloy flake 7 waste heat 8 cooling water 9 thermoelectric conversion element 10 electrode 11 conducting wire 12 insulating plate 13 heat exchanger

Claims (5)

Rare earth metal R (where R is at least one of La, Ce, Pr, Nd, Sm, Eu, Yb), transition metal T (where T is Fe, Co, Ni, Os, Ru, Pd, Pt) , A thermoelectric conversion module using a filled skutterudite alloy manufactured by melting an alloy raw material composed of metal antimony (Sb) and rapidly solidifying the molten metal by a strip casting method. A thermoelectric generator using the thermoelectric conversion module according to claim 1. A thermoelectric power generation method using the thermoelectric conversion module according to claim 1. A waste heat recovery system using the thermoelectric generator according to claim 2. A solar heat utilization system using the thermoelectric power generator according to claim 2.

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