JPH11274578A - Method for manufacturing thermoelectric conversion material and thermoelectric conversion module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoelectric conversion module which is easily manufactured and excellent in productivity. SOLUTION: First and second substrate 3 and 6 which, positioned on front and rear surfaces respectively, have electric-insulating characteristics and specified mechanical strength, first and second electrode plates 2 and 7 which are, extending in a single region, formed on the first and second substrates 3 and 6 respectively; thermoelectric conversion elements 12 wherein one end is electrically connected to the first electrode plate 2 while the other end to the second electrode plate 7, which are provided in plural numbers while mutually connected in parallel, comprising a single conduction type to provide a temperature difference on both ends for generating an electromotive force, and lead wires which, fitted to the first and second electrode plates 2 and 7 respectively, draw out a generated electric power to outside; are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a thermoelectric conversion material and a thermoelectric conversion module.

[0002]

2. Description of the Related Art In recent years, power generation using waste heat generated by thermoelectric conversion elements has been receiving a lot of attention due to serious global environmental problems. Along with this, in order to increase the conversion efficiency of the thermoelectric conversion element from heat to electricity, that is, to increase the thermoelectric conversion efficiency,
Development of thermoelectric materials has been actively carried out.

The thermoelectric properties of a thermoelectric material are represented by a performance index Z using the Seebeck coefficient S, electrical conductivity σ, and thermal conductivity κ as parameters, and Z = S ＾ 2 × σ / κ. The larger the value of the figure of merit Z, the more efficiently heat is converted to electricity. S 分子 2 × σ, which is a numerator of this equation, is particularly called a power factor.

In order to obtain a material having good thermoelectric properties, that is, a material having a large figure of merit Z, as is derived from the above equation,
What is necessary is just to make the Seebeck coefficient S and the electric conductivity σ large and to make the thermal conductivity κ small.

Since each parameter has a temperature characteristic, an optimum material is selected according to the temperature of a heat source for power generation.

Here, in the so-called medium temperature range of about 200 ° C. to 600 ° C., there are many practical heat sources around the body such as exhaust gas of automobiles and heat of incineration of refuse.
There is a particularly high expectation for the efficient conversion of these heat sources into usable electrical energy. PbTe-based materials and the like are known as thermoelectric materials in this temperature range. Therefore, practical examples are limited.

[0007] Under these circumstances, CoSb3-based materials having good properties in a medium temperature range have recently attracted attention. CoSb3 is a P-type thermoelectric semiconductor exhibiting a large Seebeck coefficient and a large electric conductivity like the P-type.
Despite the expectation of excellent thermoelectric properties that change the electrical conductivity type to N-type by adding elements such as d, Pt, and Te, it has not been put to practical use because of its high thermal conductivity. Various studies have been made on CoSb3 in order to reduce the thermal conductivity. However, when the thermal conductivity decreases, the Seebeck coefficient and the electrical conductivity also decrease, and the overall performance index Z is improved. Therefore, the thermoelectric conversion efficiency does not improve.

By the way, the thermoelectric conversion material is used as a thermoelectric conversion module in which a plurality of thermoelectric conversion elements manufactured by processing into an appropriate shape are assembled and assembled.

Here, a conventional thermoelectric conversion module will be described. FIG. 8 is a perspective view showing a conventional thermoelectric conversion module, and FIG. 9 is a plan view and a front view showing the thermoelectric conversion module of FIG.

FIG. 9A is a view in which a first electrode plate 2 is formed on a first substrate 3 made of an electrically insulating ceramic or the like, and FIG. 9B is a view in which FIG. 9A is a view in which P-type thermoelectric conversion elements 4 and N-type thermoelectric conversion elements 5 are alternately mounted on the first electrode plate 2, FIG.
9C, a second substrate 6 made of an electrically insulating ceramic or the like is further provided on the thermoelectric conversion elements 4 and 5 via a second electrode plate 7 with respect to FIG. FIG.

As shown, the thermoelectric conversion module 1
In order to maintain the mechanical strength of the thermoelectric conversion module 1, a first material made of an electrically insulating ceramic or the like is used.
The substrate 3 and the second substrate 6 are located on the front and back surfaces. The P-type thermoelectric conversion element 4 and the N-type thermoelectric conversion element 5 which are sandwiched between the first substrate 3 and the second substrate 6 and generate an electromotive force by giving a temperature difference to both ends. Are provided.

The first substrate 3 has a first electrode plate 2 made of copper or the like, and the second substrate 6 has a second electrode plate 2 made of copper or the like.
Of the electrode plates 7 are divided into a plurality of regions. The P-type thermoelectric conversion element 4 and the N-type thermoelectric conversion element 5 are connected in series by the first electrode plate 3 and the second electrode plate 7 formed separately.

In the thermoelectric conversion module 1, a lead wire 8 for extracting electric power to the outside is connected to the first electrode plate 2.

Next, the operation of such a conventional thermoelectric conversion module will be described. The thermoelectric conversion module 1 is set in an evaluation device as shown in FIG. The evaluation device is
The thermoelectric conversion module 1 includes a heating surface 9 on which an electric heater is set to heat one surface of the thermoelectric conversion module 1 and a cooling surface 10 through which cooling water for cooling the other surface of the thermoelectric conversion module 1 flows. And the lead wire 8 of the thermoelectric conversion module 1 is a measuring instrument 1 comprising an ammeter, a load resistance, and a voltmeter.
Set to 1.

When the thermoelectric conversion module 1 is set in such an evaluation device and a temperature difference is applied between one surface and the other surface of the thermoelectric conversion module 1, a P-type thermoelectric conversion module 1 is formed. An electromotive force corresponding to the temperature difference is generated at both ends of the thermoelectric conversion element 4 and the N-type thermoelectric conversion element 5 by the Seebeck effect. Holes are generated in the P-type thermoelectric conversion element 4, and electrons are generated in the N-type thermoelectric conversion element 5, respectively. An electromotive force is generated such that a current flows toward the end, and an electromotive force is generated in the N-type thermoelectric conversion element 5 such that a current flows from the low-temperature side to the high-temperature side in the element. Accordingly, the P-type thermoelectric conversion element 4 and the N-type thermoelectric conversion element 4 are electrically connected in series with the lead 8 wire of the thermoelectric conversion module 1 to connect the P-type thermoelectric conversion element 4 and the N-type thermoelectric conversion element. The sum of the thermoelectromotive forces generated from the element 5 is taken out as power.

[0016]

As described above, the CoS
Although the b3 type material is a promising material in an easy-to-use medium temperature range, it has a problem that thermoelectric properties are not improved due to high thermal conductivity, and thermoelectric conversion efficiency is low.

The conventional thermoelectric conversion module 1 has a P
Type thermoelectric conversion elements 4 and N-type thermoelectric conversion elements 5 need to be alternately connected in series, so that thermoelectric conversion elements 4 and 4 are provided on insulating plates (first substrate 3 and second substrate 6). Plural electrode plates (first electrode plate 2, second electrode plate 7) according to shape of 5
Or it is necessary to alternately arrange the P-type thermoelectric conversion elements 4 and the N-type thermoelectric conversion elements 5 on this electrode plate, which causes a problem that the assembly is complicated and lacks mass productivity.

Therefore, the present invention provides a method for producing Co having a low thermal conductivity.
An object of the present invention is to provide a thermoelectric conversion material made of an Sb3-based material.

Another object of the present invention is to provide a thermoelectric conversion module which is easy to manufacture and has excellent mass productivity.

[0020]

Means for Solving the Problems In order to solve this problem, a method for producing a thermoelectric conversion material according to the present invention comprises a first method comprising adding at least one of Pd, Pt and Ni to Co and Sb. Is prepared, and S and Se are added to Co and Sb.
And a second compound to which at least one of Te and Te is added, and the first compound and the second compound are mixed in a predetermined mixing amount and sintered.

Thus, the thermal conductivity of the thermoelectric conversion material made of a CoSb3-based material can be reduced without greatly reducing the Seebeck coefficient and the electrical conductivity.

Further, the thermoelectric conversion module of the present invention is located on each of the front and back surfaces, and has a first substrate and a second substrate having electrical insulation properties and a predetermined mechanical strength. A first electrode plate and a second electrode plate respectively formed on the first substrate and the second substrate, one end electrically connected to the first electrode plate, and the other end electrically connected to the second electrode plate, respectively; A plurality of thermoelectric conversion elements which are provided in parallel with each other and which are of a single conductivity type and generate an electromotive force by giving a temperature difference to both ends; a first electrode plate and a second electrode And a lead wire which is attached to each of the plates and takes out the generated electric power to the outside.

Thus, a thermoelectric conversion module which is easy to manufacture and has excellent mass productivity can be obtained.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The first aspect of the present invention is to produce a first compound obtained by adding at least one of Pd, Pt and Ni to Co and Sb.
A second compound is prepared by adding at least one of S, Se, and Te to Sb and Sb, and the first compound and the second compound are mixed in a predetermined mixing amount and sintered. This is a method for producing a conversion material, wherein Co is an N-type conductive material.
This has the effect of making it possible to reduce the thermal conductivity of a thermoelectric conversion material made of an Sb3-based material without significantly reducing the Seebeck coefficient and the electrical conductivity.

According to a second aspect of the present invention, in the first aspect of the present invention, the mixing amount of the first compound and the second compound is determined based on the occupation amount of the second compound with respect to the first compound. Is a method for producing a thermoelectric conversion material having a molecular ratio in the range of 5% to 95%. The thermal conductivity of a thermoelectric conversion material made of a CoSb3-based material exhibiting N-type electrical conductivity is determined by the Seebeck coefficient and the electrical conductivity. Has the effect of being able to be reduced without significantly reducing it.

According to a third aspect of the present invention, in the first aspect of the present invention, the mixing amount of the first compound and the second compound is determined by determining the occupation amount of the second compound with respect to the first compound. Is a method for producing a thermoelectric conversion material having a molecular ratio in the range of 10% to 90%, wherein CoSb3 exhibiting N-type electric conductivity.
This has the effect that the thermal conductivity of a thermoelectric conversion material made of a system material can be reduced without greatly reducing the Seebeck coefficient and the electrical conductivity.

According to a fourth aspect of the present invention, a first substrate and a second substrate having electrical insulation properties and predetermined mechanical strength, which are located on the front and back surfaces, respectively, are spread over a single area. A first electrode plate and a second electrode plate respectively formed on the first substrate and the second substrate,
The other end is electrically connected to the second electrode plate, and the other end is connected in parallel with each other. A single conductive type is provided, and a temperature difference is applied to both ends. A thermoelectric conversion module having a thermoelectric conversion element for generating electric power, and a lead wire attached to each of the first electrode plate and the second electrode plate to take out generated electric power to the outside. Since a thermoelectric conversion element is used, there is no need to divide the electrode plate into a plurality of regions on the insulating plate and form an electrode plate to connect the P-type and N-type thermoelectric conversion elements alternately in series, which facilitates manufacturing. Thus, a thermoelectric conversion module having excellent mass productivity can be obtained.

According to a fifth aspect of the present invention, a first substrate and a second substrate having electrical insulation properties and a predetermined mechanical strength, which are located on the front and back surfaces, respectively, are spread over a single region. A first electrode plate and a second electrode plate respectively formed on the first substrate and the second substrate; a third electrode plate formed on the first substrate; On the board,
The other end is electrically connected to the second electrode plate and is connected in parallel with each other. A plurality of thermoelectric generators are provided, each of which has a single conductivity type and generates an electromotive force by giving a temperature difference to both ends. A converter element, one end of which is electrically connected to the third electrode plate, and the other end of which is electrically connected to the second electrode plate, and which generates electric power generated in the second electrode plate by the thermoelectric conversion element; And a lead wire attached to the first electrode plate and the third electrode plate, respectively, for extracting generated power to the outside, and is a single conduction type thermoelectric conversion element. Is used, an electrode plate is formed by dividing the insulating plate into a plurality of regions, and a P-type and an N-type are formed.
This eliminates the need to alternately connect the thermoelectric conversion elements of the type in series, and has the effect of obtaining a thermoelectric conversion module that is easy to manufacture and has excellent mass productivity. In addition, power can be taken out from two lead wires attached to the first and third electrode plates in the same temperature range without deteriorating the characteristics of the thermoelectric conversion module. Has the effect that it can be easily incorporated into a heat exchanger or the like.

According to a sixth aspect of the present invention, there is provided a thermoelectric conversion module according to the fifth aspect, wherein the conductor is a connection element of a conductivity type different from the conductivity type of the thermoelectric conversion element. This has the effect of obtaining a thermoelectric conversion module that is easy and has excellent mass productivity. In addition, it has an effect that it can be easily incorporated into a heat exchanger or the like.

According to a seventh aspect of the present invention, there is provided the thermoelectric conversion module according to the fifth aspect, wherein the conductor is a metal, and the thermoelectric conversion module is easy to manufacture and has excellent mass productivity. Has the effect of being In addition, it has an effect that it can be easily incorporated into a heat exchanger or the like.

[0031] The invention according to claim 8 of the present invention is characterized in that a first substrate and a second substrate having conductivity and a predetermined mechanical strength are respectively located on the front and back surfaces, and one end of the first substrate and the first substrate. The other end is electrically connected to the second substrate, and a plurality of the other end are connected in parallel with each other. The plurality of end portions are of a single conductivity type, and a temperature difference is applied to both ends to generate an electromotive force. A thermoelectric conversion module having a thermoelectric conversion element and a lead wire attached to the first substrate and the second substrate, respectively, for extracting generated power to the outside;
Since the first substrate and the second substrate that maintain mechanical strength have electrical conductivity and also serve as an electrode plate, the thermoelectric conversion element can be directly connected to the first substrate without forming the electrode plate again. The electrical connection is established simply by fixing the thermoelectric conversion module to the second substrate, which has an effect of obtaining a thermoelectric conversion module having more excellent mass productivity. Moreover, since the temperature given from the outside can be efficiently transmitted from the first substrate and the second substrate to both ends of the thermoelectric conversion element, a large temperature difference can be given by the thermoelectric conversion element, This has the effect that the thermoelectric conversion efficiency is further increased and electric power can be extracted extremely efficiently.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a thermoelectric conversion material according to the first, second, or third aspect, wherein the thermoelectric conversion element is provided in the fourth, fifth, sixth, seventh, or eighth aspect. Is a thermoelectric conversion module using the thermoelectric conversion material obtained by the method described above, and has an effect that power can be efficiently extracted from heat in a so-called middle temperature range of about 200 ° C. to 600 ° C.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

(Embodiment 1) Hereinafter, Pt is added to CoSb3.
A thermoelectric conversion material according to the present embodiment, which is obtained by mixing a first compound in which is dissolved in a solid solution with a second compound in which Te is dissolved in CoSb3 will be described.

In this thermoelectric conversion material, the first compound consisting of Co, Sb and Pt is produced as follows.

First, Co and Sb having a purity of 99.99% or more are used.
The raw material powders of Pt and Pt were (CoSb3) 0.9, P
Weigh to an atomic ratio of t0.1. After weighing, the mixture is thoroughly stirred and mixed so that the raw material powders are homogeneous. After mixing, molding is performed to form a first pellet. And
After molding, the first pellet is placed in a quartz tube coated with carbon.

Next, the quartz tube containing the first pellets is set in an electric furnace, and a primary reaction is performed to combine the raw material powders. The electric furnace replaces the Ar gas after performing evacuation. The primary reaction is performed, for example, at 800 ° C. in an Ar gas atmosphere.
At about 30 hours. Thereafter, the first pellets are taken out when the temperature of the electric furnace is lowered to room temperature by slow cooling, whereby a first compound composed of Co, Sb and Pt is produced.

The second compound composed of Co, Sb and Te is prepared in the same manner as the first compound composed of Co, Sb and Pt.

That is, the raw material powders of Co, Sb and Te having a purity of 99.99% or more were respectively (CoSb3) 0.
9. Weigh to an atomic ratio of Te0.1. After weighing, the mixture is thoroughly stirred and mixed so that the raw material powders are homogeneous. After mixing, molding is performed to form a second pellet.
Then, after molding, the second pellet is put into a quartz tube coated with carbon.

Next, the quartz tube containing the second pellets is set in an electric furnace, and a primary reaction is performed to combine the raw material powders. The electric furnace replaces the Ar gas after performing evacuation. The primary reaction is performed, for example, at 800 ° C. in an Ar gas atmosphere.
At about 30 hours. Thereafter, the second pellet is taken out when the temperature of the electric furnace is lowered to room temperature by slow cooling, whereby a second compound composed of Co, Sb, and Te is produced.

Next, the first compound and the second compound are mixed and sintered. Here, first, in order to uniformly mix the first compound and the second compound, each of the first compound and the second compound is pulverized into a powder having a size of about 90 μm or less.

Next, the powder of the first compound and the powder of the second compound are weighed so as to have a predetermined mixing ratio, and the two kinds of powder are mixed well so that the powders are homogeneous. To produce a raw material powder for sintering.

The raw material powder thus manufactured is sintered by a hot press method to manufacture the thermoelectric conversion material of the present embodiment.

The hot pressing is performed as follows. The dies and punches are made of graphite. The die is filled with the raw material powder, and after inserting a punch, it is set in a hot press. After evacuating the hot press, Ar gas is introduced. Then, for example, a temperature of 730 ° C. and a pressure of 20
Sintering is performed for 60 minutes under the sintering conditions of MPa.

Thus, a thermoelectric conversion material in which the first compound in which Pt is dissolved in CoSb3 and the second compound in which Te is dissolved in CoSb3 is mixed is produced.

A sample of a comparative example for evaluating such a thermoelectric conversion material, that is, C having the same composition as the material
A thermoelectric conversion material composed of o, Sb, Pt, and Te is manufactured as follows.

First, Co and Sb having a purity of 99.99% or more are used.
After weighing the raw material powders of Pt and Te, they are mixed well so that the raw material powders are homogeneous. After mixing, the mixture is molded into pellets. After molding, the pellets are placed in a quartz tube coated with carbon.

Next, the quartz tube containing the pellets is set in an electric furnace, and a primary reaction is performed to combine the raw material powders.
The electric furnace replaces the Ar gas after performing evacuation. The primary reaction is performed in an Ar gas atmosphere at a temperature of, for example, 800 ° C. for about 30 hours. Thereafter, the pellets are gradually cooled and the pellets are taken out when the temperature of the electric furnace reaches room temperature. Next, although mixing of the powders is not performed, the pellets after the primary reaction are pulverized into powder having a size of about 90 μm or less in order to homogenize the composition in the primary reaction product. Then, the powder is set in a hot press apparatus, and after the hot press apparatus is evacuated, Ar gas is introduced. Then, sintering is performed for 60 minutes at a temperature of 730 ° C. and a pressure of 20 MPa, for example.

In this manner, a comparative example consisting of Co, Sb, Pt, and Te is prepared.

Here, the thermoelectric conversion material according to the present embodiment is a compound comprising Co, Sb and Pt, and a compound comprising Co and Sb.
On the other hand, the sample of the comparative example is manufactured by mixing and sintering a compound comprising Ti and Te, and then pulverizing after mixing and reacting Co, Sb, Pt and Te from the stage of the raw material powder. It is manufactured by sintering without mixing with other compounds.

Next, for the thermoelectric conversion material of the present embodiment and the sample of the comparative example manufactured as described above, the power factor and the thermal conductivity were measured to obtain a figure of merit, thereby evaluating the thermoelectric characteristics. went.

FIG. 1 is a graph showing the thermoelectric characteristics of the thermoelectric conversion material according to the first embodiment of the present invention and the sample of the comparative example. FIG. 1A shows the power factor when the mixing amount is changed. 1 (b) shows the change in the thermal conductivity when the mixing amount is changed, and FIG. 1 (c) shows the change in the figure of merit when the mixing amount is changed. The mixing amount on the horizontal axis indicates the ratio of the mixing amount in the molecular ratio of the powder of the second compound to the powder of the first compound.

FIGS. 1 (a), 1 (b) and 1 (c)
As shown in the figure, the power factor hardly changes when the powder of the second compound is mixed with the powder of the first compound. The mixture of the powder of the first compound and the powder of the second compound has a lower thermal conductivity than that of the powder of the first compound and the powder of the second compound alone. Further, the figure of merit indicating the performance of the thermoelectric conversion material is obtained by mixing the powder of the first compound and the powder of the second compound in the case of a single powder of the first compound and the powder of the second compound. It shows a value larger than.

On the other hand, although the composition is the same as that of the first embodiment, the sample of the comparative example prepared by mixing the raw material powders of Co, Sb, Pt, and Te from the stage of the primary reaction is the same as the first compound. Although the thermal conductivity is smaller than that of the powder and the powder of the second compound alone, the power factor is also reduced at the same time, so that the figure of merit has not been improved.

As described above, simply Co, Sb, Pt, and Te
Does not necessarily improve the thermoelectric properties. As shown in the present embodiment, first, the first compound powder composed of Co, Sb, and Pt, Co, Sb, and Tb
e) and a powder of a second compound consisting of
Then, by mixing and sintering them, the thermoelectric properties are improved.

As can be seen from FIG. 1C, the mixing amount is effective in improving the figure of merit in the range of 5% to 95%. However, considering the stability of performance, the mixing amount is 10% to 9%.
A range of 0% is desirable.

In this embodiment, the additive element is P
Although the case where t and Te are shown is shown, the additive element is P
The first compound is not limited to t and Te,
If at least one of Ni, Pt and Pd is added to o and Sb, the second compound is at least one of S, Se and Te to Co and Sb. In any combination, the thermal conductivity is reduced and the figure of merit is improved without reducing the power factor in any combination.

(Embodiment 2) FIG. 2 is a perspective view showing a thermoelectric conversion module according to Embodiment 2 of the present invention, and FIG. 3 is a plan view and a front view showing the thermoelectric conversion module of FIG.

The thermoelectric conversion elements in the thermoelectric conversion modules according to the second, third and fourth embodiments use the thermoelectric conversion materials manufactured in the first embodiment.

FIG. 3A is a view in which a first electrode plate 2 is formed on a first substrate 3 made of an electrically insulating ceramic or the like, and FIG. 3B is a view in which FIG. FIG. 3A is a view in which a plurality of N-type thermoelectric conversion elements 12 are mounted on the first electrode plate 2, and FIG. 3C is further a view of FIG. A second substrate 6 made of ceramics or the like having electrical insulation properties is provided on the thermoelectric conversion element 12.
FIG. 3 is a diagram mounted via an electrode plate 7 of FIG.

As shown, the thermoelectric conversion module 1
In order to maintain the mechanical strength of the thermoelectric conversion module 1, a first material made of an electrically insulating ceramic or the like is used.
The substrate 3 and the second substrate 6 are located on the front and back surfaces. A plurality of N-type thermoelectric conversion elements 12 are provided between the first substrate 3 and the second substrate 6 to generate an electromotive force by applying a temperature difference to both ends.

The first substrate 3 has the first electrode plate 2
A second electrode plate 7 is formed on each of the substrates 6 so as to extend in a single region, and one end of the thermoelectric conversion element 12 has the first end.
And the other end is electrically connected to the second electrode plate 7 and connected in parallel with each other.

In this thermoelectric conversion module 1, two lead wires 8 for extracting electric power to the outside are connected to the first electrode plate 2 and the second electrode plate 7, respectively.

In the present embodiment, a ceramic material containing alumina as a main component is used for the second substrate 6 and the first substrate 3 having electrical insulation, and the second electrode plate 7 and the first
The electrode plate 2 is made of an electrode material mainly composed of Ni. Further, as described above, the N-type thermoelectric conversion material described in Embodiment 1 is used for the thermoelectric conversion element 12.

Next, the operation of the thermoelectric conversion module 1 shown in this embodiment will be described. FIG. 1 shows a thermoelectric conversion module 1.
When the thermoelectric conversion module 1 is set in the evaluation device shown in FIG. 0 and a temperature difference is given between one surface and the other surface of the thermoelectric conversion module 1,
An electromotive force corresponding to the temperature difference is generated at both ends of the thermoelectric conversion element 12 by the Seebeck effect. In the N-type thermoelectric conversion element 12, electrons serve as a basis for generating an electromotive force, so that an electromotive force is generated in the thermoelectric conversion element 12 such that a current flows from a lower temperature side to a higher temperature side. Therefore, the N-type thermoelectric conversion element 1
From the lead wires 8 of the thermoelectric conversion module 1 electrically connected in parallel to each other, the number of N-type thermoelectric conversion elements 12 constituting the thermoelectric conversion module 1 is determined by the electromotive force generated from the N-type thermoelectric conversion element 12. The electric power of the added current amount can be taken out according to.

Here, the N-type thermoelectric conversion element 12 uses the thermoelectric conversion material having high thermoelectric conversion efficiency described in the first embodiment, so that the heat applied to the thermoelectric conversion module 1 is efficiently reduced. Power can be extracted.

Since the thermoelectric conversion module 1 of the second embodiment is composed of a single conduction type thermoelectric conversion element 12 called N-type, the N-type and P-type thermoelectric conversion elements are connected in series as in the prior art. No need to connect. In addition, the second electrode plate 7 and the first electrode plate 2 for electrically connecting the thermoelectric conversion elements 12 may be formed in a single region, and may be formed in a plurality of regions as in the related art. There is no need to divide and form. Therefore, the manufacture of the thermoelectric conversion module 1 is facilitated, and excellent mass productivity can be obtained.

In this embodiment, the thermoelectric conversion element 1
Although an N-type thermoelectric conversion material is used for 2, a P-type thermoelectric conversion material may be used.

The thermoelectric conversion element 12 of the present embodiment uses a CoSb-based thermoelectric conversion material having good characteristics in a middle temperature range. Various other materials as shown can be used. However, when selecting a material, it is necessary to select a thermoelectric conversion material having good thermoelectric properties in a temperature range in which the thermoelectric conversion module operates.

(Embodiment 3) FIG. 4 is a perspective view showing a thermoelectric conversion module according to Embodiment 3 of the present invention, and FIG. 5 is a plan view and a front view showing the thermoelectric conversion module of FIG.

Here, FIG. 5A is a view in which a first electrode plate 2 and a third electrode plate 13 are formed on a first substrate 3 made of an electrically insulating ceramic or the like. (B)
5A, a plurality of N-type thermoelectric conversion elements 12 are mounted on the first electrode plate 2, and a connection element (conductor) 14 is mounted on the third electrode plate 13. FIG. 5
FIG. 5C further shows the thermoelectric conversion element 1 shown in FIG.
FIG. 2 is a view in which a second substrate 6 made of an electrically insulating ceramic or the like is mounted on a second electrode plate 7 and a connection element 14 via a second electrode plate 7.

As shown, the thermoelectric conversion module 1
In order to maintain the mechanical strength of the thermoelectric conversion module 1, a first material made of an electrically insulating ceramic or the like is used.
The substrate 3 and the second substrate 6 are located on the front and back surfaces. A plurality of N-type thermoelectric conversion elements 12 and connection elements 14 that generate an electromotive force by applying a temperature difference to both ends so as to be sandwiched between the first substrate 3 and the second substrate 6 are provided. Have been.

The first substrate 3 has the first electrode plate 2
A second electrode plate 7 is formed on a single substrate 6 to extend over a single region, and a third electrode plate 13 is formed on the first substrate 3. And the thermoelectric conversion element 1
2 has one end electrically connected to the first electrode plate 3 and the other end electrically connected to the second electrode plate 7, respectively, and is connected in parallel with each other;
The connection element 14 has one end electrically connected to the third substrate 13 and the other end electrically connected to the second substrate 7. In addition,
The connection element 14 is formed of a material having a very small Seebeck coefficient.

In such a thermoelectric conversion module 1, two lead wires 8 for extracting electric power to the outside are connected to the first electrode plate 2 and the third electrode plate 13, respectively.

As described above, in the thermoelectric conversion module 1 according to the present embodiment, the 2
One of the lead wires 8 is attached to the first electrode plate 2 to which the thermoelectric conversion element 12 is connected, and the other is connected to the third electrode plate 13 to which the connection element 14 is connected. Installed.

In the second embodiment described above, the two lead wires 8 for taking out the electric power from the thermoelectric conversion module 1 to the outside are connected to the first substrate 3 and the second substrate 7 at the opposing positions.
That is, the thermoelectric conversion module 1 is attached to the high temperature side and the low temperature side. This has no problem from the viewpoint of the characteristics of the thermoelectric conversion module 1. However, when the thermoelectric conversion module 1 is actually mounted on a heat exchanger or the like, the two lead wires 8 are connected to the high temperature side and the high temperature side or the low temperature side. In some cases, it is easier to use the battery pack taken out from the electrode plate in the same temperature range, such as the low temperature side.

Therefore, the thermoelectric conversion module 1 according to the present embodiment has a configuration in which two lead wires 8 are taken out from the electrode plates in the same temperature range.

In the present embodiment, a ceramic material containing alumina as a main component is used for the second substrate 6 and the first substrate 3 having electrical insulation, and the second electrode plate 7 and the first For the electrode plate 2 and the third electrode plate 13, an electrode material containing Ni as a main component is used. The thermoelectric conversion element 12 uses the N-type thermoelectric conversion material described in the first embodiment. The connection element 14 for transmitting the electric power generated by the second electrode plate 7 to the third electrode plate 13 includes Ni
Is used as a main component.

Next, the operation of the thermoelectric conversion module 1 according to the third embodiment will be described. When the thermoelectric conversion module 1 of the present embodiment is set on the evaluation device shown in FIG. 10 and a temperature difference is applied between one surface and the other surface of the thermoelectric conversion module 1, the electric conversion element 12 is formed by the Seebeck effect. An electromotive force corresponding to the temperature difference is generated at both ends of the. In the N-type thermoelectric conversion element 12, an electromotive force is generated such that a current flows from the low temperature side to the high temperature side in the element.

Here, since the connecting element 14 is made of a material having an extremely small Seebeck coefficient, even if there is a temperature difference between both ends of the connecting element 14, the electromotive force generated by this is extremely small. . Therefore, the second electrode plate 7 and the third electrode plate 13 can be electrically connected via the connection element 14 without deteriorating the characteristics of the thermoelectric conversion module 1. Thus, the thermoelectric conversion module according to the second embodiment extracts power from the lead wire 8 connected to the low-temperature side and the lead wire 8 connected to the high-temperature side, whereas the thermoelectric conversion module according to the present embodiment In the module 1, electric power is extracted from the two lead wires 8 attached to the first electrode plate 3 and the third electrode plate 13 in the same temperature range, without deteriorating the characteristics of the thermoelectric conversion module 1. It becomes possible.

Here, in order to prevent the output from the thermoelectric conversion module 1 from deteriorating, a material having an extremely small Seebeck coefficient is used for the connection element 14, but the thermoelectric conversion element 12 of the thermoelectric conversion module 1 has N Since the connection element is a type, a thermoelectric conversion element having a P-type electric conduction type can be used as the connection element. However, in order to prevent the characteristics of the thermoelectric conversion module 1 from deteriorating, it is necessary that the characteristics of the P-type thermoelectric conversion element do not significantly differ from the characteristics of the N-type thermoelectric conversion element 12.

That is, in the thermoelectric module 1 of the present embodiment in which the thermoelectric conversion element 12 is of the N type, in order to take out the generated power without deteriorating, the second electrode plate 7
Connection element 1 for sending power from the third electrode plate 13
For 4, a material having an extremely small Seebeck coefficient or a P-type element different from the conduction type with the thermoelectric conversion element 12 may be used.

In this embodiment, the thermoelectric conversion element 1
For N, an N-type thermoelectric conversion material containing CoSb as a main component is used, but as the thermoelectric conversion material, various other materials such as a metal having excellent thermoelectric characteristics can be used. The conductivity type may be P-type. However, in the case of a P-type thermoelectric conversion material, a connection element for transmitting power from the second electrode plate 7 to the third electrode plate 13 in order to extract the power from the thermoelectric conversion module 1 without deterioration. 14 must be made of a material having an extremely small Seebeck coefficient, or an N-type material different from the P-type thermoelectric conversion element and the conduction type.

(Embodiment 4) FIG. 6 is a perspective view showing a thermoelectric conversion module according to Embodiment 4 of the present invention, and FIG. 7 is a plan view and a front view showing the thermoelectric conversion module of FIG.

Here, FIG. 7A shows the first conductive material.
FIG. 7B is a diagram showing a plurality of N-type thermoelectric conversion elements 12 mounted on a first substrate 15 in addition to FIG. 7A, and FIG. ) Is a second conductive layer on the thermoelectric conversion element 12 as compared with FIG.
FIG.

As shown, the thermoelectric conversion module 1
In order to maintain the mechanical strength of the thermoelectric conversion module 1, a first substrate 15 and a second substrate 16 made of, for example, a copper alloy and having conductivity are located on the front and back surfaces.

Then, a plurality of N-type thermoelectric conversion elements 12 which generate an electromotive force by applying a temperature difference to both ends so as to be sandwiched between the first substrate 3 and the second substrate 6 are provided.
Is provided. That is, one end of the thermoelectric conversion element 12 is electrically connected to the first substrate 15 and the other end is electrically connected to the second substrate 16, and are mutually connected in parallel.

In such a thermoelectric conversion module 1, two lead wires 8 for extracting electric power to the outside are connected to the first substrate 15 and the second substrate 16, respectively.

As described above, the thermoelectric conversion module 1 of the present embodiment differs from the thermoelectric conversion modules 1 of the second and third embodiments in that the first substrate 15 and the second substrate 15 for maintaining the mechanical strength are maintained. The substrate 16 has electrical conductivity and also serves as an electrode plate.

As a result, it is possible to electrically connect the thermoelectric conversion elements 12 only by directly fixing them to the first substrate 15 and the second substrate 16 without newly forming an electrode plate. Therefore, the thermoelectric conversion module 1 can be manufactured more efficiently.

Further, since the first substrate 15 and the second substrate 16 are formed of a copper alloy and have high thermal conductivity, the temperature applied from the outside can be efficiently reduced by the thermoelectric conversion element 1.
2 can be transmitted to both ends. Therefore, a large temperature difference can be provided by the thermoelectric conversion element 12, the thermoelectric conversion efficiency is further increased, and electric power can be extracted very efficiently.

Here, in the case of a conventional thermoelectric conversion module composed of a P-type element and an N-type element, it is necessary to electrically connect the P-type element and the N-type element in series. As shown in the present embodiment, a first substrate 15 and a second substrate 1 serving as protective materials for maintaining a mechanical strength of a copper alloy plate having electrical conductivity and excellent thermal conductivity.
6 could not be used.

However, in the case of the thermoelectric conversion element shown in the first embodiment, since it can be used only with the N-type element without being combined with the P-type element, as shown in the fourth embodiment, Thus, the thermoelectric conversion module 1 using the first substrate 15 and the second substrate 16 having conductivity and mechanical strength can be manufactured.

In the present embodiment, an N-type thermoelectric conversion material whose main component is CoSb is used for the thermoelectric conversion element. However, the thermoelectric conversion element is not limited to this. Various other excellent materials can be used. In addition, the conduction type of the thermoelectric conversion element may be P-type or N-type.

Further, the first substrate 15 and the second substrate 16 having mechanical strength and conductivity are not limited to copper alloy, but have electrical conductivity, high thermal conductivity, What is necessary is just to maintain the mechanical strength of the thermoelectric conversion module. As described above, according to the thermoelectric conversion module of the present embodiment, it is possible to manufacture a reliable module having excellent environmental resistance characteristics and excellent electrical contact with good mass productivity. With this thermoelectric conversion module, thermoelectric generation using waste heat contained in automobile exhaust gas, thermoelectric generation using waste incineration waste heat, factory waste heat, power plant waste heat, radioactive waste Thermal energy generation using waste heat, etc., enables efficient conversion of conventionally discarded thermal energy into easy-to-use electrical energy, which is especially effective for environmental issues such as prevention of global warming. is there.

[0096]

As described above, according to the present invention, CoS
An advantageous effect is obtained in that the thermal conductivity of the thermoelectric conversion material made of a b3 material can be reduced without significantly reducing the Seebeck coefficient and the electrical conductivity.

As a result, an effective effect is obtained in that the thermoelectric characteristics are improved and the conversion from heat to electric power can be performed efficiently.

Further, according to the present invention, since a single conduction type thermoelectric conversion element is used, the electrode plate is divided into a plurality of regions on the insulating plate to form P-type and N-type. There is no need to alternately connect the thermoelectric conversion elements in series, and an effective effect of obtaining a thermoelectric conversion module that is easy to manufacture and has excellent mass productivity can be obtained.

The first substrate and the second substrate have the first
And a third electrode plate formed on the first substrate, and the electric power generated on the second electrode plate is transmitted to the third electrode plate by a conductor. Then, it is possible to extract power from the two lead wires attached to the first and third electrode plates in the same temperature range without deteriorating the characteristics of the thermoelectric conversion module. Therefore, an effective effect that the incorporation into a heat exchanger or the like becomes easy can be obtained.

If the thermoelectric conversion element is connected to the first substrate and the second substrate having conductivity and mechanical strength, the electric power can be obtained simply by fixing the thermoelectric conversion element directly to the first substrate and the second substrate. Since the electrical connection is performed, an effective effect of obtaining a thermoelectric conversion module having more excellent mass productivity can be obtained.

Further, since a temperature applied from the outside can be efficiently transmitted from the first substrate and the second substrate to both ends of the thermoelectric conversion element, a large temperature difference can be provided by the thermoelectric conversion element. As a result, the thermoelectric conversion efficiency is further increased, and an effective effect that power can be taken out very efficiently can be obtained.

If the thermoelectric conversion element obtained by the above-described method for manufacturing a thermoelectric conversion material is used for the thermoelectric conversion element in such a thermoelectric conversion module, power can be efficiently extracted from heat in a medium temperature range. Is obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing thermoelectric characteristics of a thermoelectric conversion material according to a first embodiment of the present invention and a sample of a comparative example.

FIG. 2 is a perspective view showing a thermoelectric conversion module according to Embodiment 2 of the present invention.

FIG. 3 is a plan view and a front view showing the thermoelectric conversion module of FIG. 2;

FIG. 4 is a perspective view showing a thermoelectric conversion module according to Embodiment 3 of the present invention.

5 is a plan view and a front view showing the thermoelectric conversion module of FIG.

FIG. 6 is a perspective view showing a thermoelectric conversion module according to Embodiment 4 of the present invention.

FIG. 7 is a plan view and a front view showing the thermoelectric conversion module of FIG. 6;

FIG. 8 is a perspective view showing a conventional thermoelectric conversion module.

9 is a plan view and a front view showing the thermoelectric conversion module of FIG.

FIG. 10 is a schematic diagram showing the configuration of a thermoelectric conversion module evaluation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermoelectric conversion module 2 1st electrode plate 3 1st substrate 6 2nd substrate 7 2nd electrode plate 8 Lead wire 12 Thermoelectric conversion element 13 3rd electrode plate 14 Connection element (conductor) 15 1st Substrate 16 Second substrate

Claims (9)

[Claims] 1. A first compound is prepared by adding at least one of Pd, Pt and Ni to Co and Sb, and at least one of S, Se and Te is added to Co and Sb. A method for producing a thermoelectric conversion material, comprising: preparing a second compound, and mixing and sintering the first compound and the second compound in a predetermined mixing amount. 2. The mixing amount of the first compound and the second compound is such that the occupation amount of the second compound with respect to the first compound is in a range of 5% to 95% in molecular ratio. The method for producing a thermoelectric conversion material according to claim 1, wherein: 3. The mixing amount of the first compound and the second compound is such that the occupation amount of the second compound with respect to the first compound is in a range of 10% to 90% in molecular ratio. The method for producing a thermoelectric conversion material according to claim 1, wherein: 4. A first substrate and a second substrate which are respectively located on the front and back surfaces and have electrical insulation properties and a predetermined mechanical strength; and a first region and a second region which spread over a single region. A first electrode plate and a second electrode plate respectively formed on the substrate, and one end electrically connected to the first electrode plate and the other end electrically connected to the second electrode plate. A plurality of thermoelectric conversion elements that are connected in parallel to each other, are of a single conductivity type, and generate an electromotive force by applying a temperature difference to both ends; and the first electrode plate and the second electrode plate. A thermoelectric conversion module, wherein the thermoelectric conversion module has a lead wire that is attached to each other and that takes out generated power to the outside. 5. A first substrate and a second substrate which are respectively located on the front and back surfaces and have electrical insulation properties and a predetermined mechanical strength, and a first region and a second region which spread over a single region. A first electrode plate and a second electrode plate respectively formed on the first substrate, a third electrode plate formed on the first substrate, one end of the first electrode plate, and the other end of the third electrode plate. A plurality of thermoelectric conversion elements each of which is electrically connected to the second electrode plate and connected in parallel with each other, is provided in a plurality, has a single conductivity type, and generates an electromotive force by giving a temperature difference to both ends. The other end is electrically connected to the third electrode plate, and the other end is electrically connected to the second electrode plate. The power generated on the second electrode plate by the thermoelectric conversion element is transferred to the third electrode plate. A conductor to be sent to the first electrode plate and the third electrode plate; Respectively attached to the plate, the thermoelectric conversion module; and a lead wire for taking out the generated power to outside. 6. The thermoelectric conversion module according to claim 5, wherein the conductor is a connection element of a conductivity type different from the conductivity type of the thermoelectric conversion element. 7. The thermoelectric conversion module according to claim 5, wherein said conductor is a metal. 8. A first substrate and a second substrate which are respectively located on the front and back surfaces and have conductivity and predetermined mechanical strength, one end of the first substrate and the other end of the second substrate. A plurality of thermoelectric conversion elements, each of which is electrically connected to the substrate and connected in parallel with each other, is provided with a single conductivity type, and generates an electromotive force by applying a temperature difference to both ends; And a lead wire attached to the substrate and the second substrate, respectively, for extracting generated power to the outside. 9. The thermoelectric conversion element, wherein a thermoelectric conversion material obtained by the method for producing a thermoelectric conversion material according to claim 1, 2 or 3 is used.
The thermoelectric conversion module according to 5, 6, 7 or 8.