Thermoelectric leg, manufacturing method for same, and thermoelectric device comprising same

Abstract

A thermoelectric leg, a manufacturing method for same, and a thermoelectric device comprising same are disclosed. The method for manufacturing the thermoelectric leg may comprise: a sintered solid formation step comprising a basic sintering step of sintering, by hot pressing in a mold, a soluble material powder or a semiconductor material powder, and an additional sintering step of additionally sintering, by hot pressing in another mold, the sintered solid and the soluble material powder or the semiconductor material powder one or more times so as to form a sintered solid for dissolution, comprising both the soluble material and the semiconductor material; and a hollow formation step of forming a hollow by exposing the soluble material in the sintered solid for dissolution to a solvent and selectively removing same.

Description

Thermoelectric leg and method for manufacturing the same, and thermoelectric element including the same

[0001] The present invention relates to a thermoelectric leg, a method for manufacturing the same, and a thermoelectric element including the same.

[0002] Thermoelectric devices generate electricity using the thermoelectric effect, exploiting the principle that temperature differences induce potential differences between metals. These devices are composed of expensive p-type and n-type LEGs, and reducing the cost of power generation is crucial for commercialization. The present invention proposes a novel thermoelectric device structure that significantly reduces the use of thermoelectric materials, thereby lowering the cost of power generation. Specifically, a sintering-dissolution process using a soluble material, such as NaCl, creates a structure with an open center, offering the potential to increase power generation efficiency and reduce costs.

[0003] The challenge of the present invention is to maintain or improve the performance of a thermoelectric device while reducing its power generation cost. To this end, we propose a method to reduce material usage by developing a thermoelectric leg with a novel structure that includes a hollow space (space or hole). This approach can help reduce material costs and energy consumption during the manufacturing process. Furthermore, this structural modification has the potential to positively impact the thermal and electrical properties of the thermoelectric device, thereby improving its performance.

[0004] In one aspect, the present invention provides a thermoelectric leg comprising a semiconductor and at least one hollow formed in the semiconductor.

[0005] In one embodiment, the hollow may penetrate a side surface of the thermoelectric leg.

[0006] In one embodiment, the hollow can be formed and closed within the thermoelectric leg.

[0007] In one embodiment, the hollow can extend vertically through the thermoelectric leg.

[0008] In one embodiment, the thermoelectric leg may further include an insert spacer positioned within the hollow.

[0009] In one embodiment, the insertion spacer may be formed in a tubular shape including a sub-hollow extending vertically through the insertion spacer.

[0010] In one embodiment, the insertion spacer may be formed in an I-beam shape having an I-shaped cross section.

[0011] In one embodiment, the insertion spacer may have the same height as the hollow.

[0012] In one embodiment, the semiconductor may include one or more semiconductor materials selected from the group consisting of BiTeSe, BiSbTe, Bi2Te3, PbTe, SiGe, GeTe, Sb2Te3, AgSbTe2, Cu2Se, InSb, MgSi, and Zn2Sb.

[0013] In another aspect, the present invention provides a thermoelectric device comprising: a plurality of p-type and n-type thermoelectric legs; a plurality of conductors in contact with at least some of the p-type and n-type thermoelectric legs; a first electrode in contact with at least some of the conductors; and a second electrode in contact with at least some of the conductors and spaced apart from the first electrode.

[0014] In one embodiment, at least some of the thermoelectric legs may be thermoelectric legs according to the embodiments of the present invention described above.

[0015] In another aspect, the present invention provides a method for manufacturing a thermoelectric leg, comprising: a basic sintering step of sintering a powder of a soluble material or a powder of a semiconductor material by a hot press process within a mold; and an additional sintering step of performing a process of additionally sintering the sintered solid and the powder of the soluble material or the powder of the semiconductor material by a hot press process within another mold at least once to form a sintered solid for dissolution containing both the soluble material and the semiconductor material; and a hollow formation step of selectively removing the soluble material from the sintered solid for dissolution by exposing it to a solvent to form a hollow.

[0016] In one embodiment, the soluble material may be placed so that the hollow formed in the hollow forming step penetrates the side surface of the thermoelectric leg.

[0017] In one embodiment, the soluble material may be placed so that the hollow formed in the hollow forming step is closed inside the thermoelectric leg.

[0018] In one embodiment, the sintered portion of the semiconductor material powder may have one or more holes formed therein to expose the soluble material to the solvent.

[0019] In one embodiment, the sintered solid formation step may be performed two or more times with the additional sintering step so that the sintered solid of the semiconductor material is inserted into the portion where the soluble material is sintered.

[0020] In one embodiment, the sintered solid of the semiconductor material can be formed into a tubular or I-beam shape.

[0021] In one embodiment, the semiconductor material may include one or more semiconductor materials selected from the group consisting of BiTeSe, BiSbTe, Bi2Te3, PbTe, SiGe, GeTe, Sb2Te3, AgSbTe2, Cu2Se, InSb, MgSi, and Zn2Sb.

[0022] In one embodiment, the soluble material may include sodium chloride (NaCl).

[0023] The effects of the present invention offer the potential to simultaneously improve the efficiency and cost-effectiveness of thermoelectric devices. Specifically, by reducing material costs and manufacturing complexity through the use of a novel thermoelectric leg structure, the overall production process can be improved in terms of energy efficiency and cost-effectiveness. Furthermore, this invention can achieve weight reduction and miniaturization without compromising the performance of thermoelectric devices, broadening their applicability in various applications. For example, it can be effectively utilized in waste heat recovery systems for transportation vehicles such as automobiles and aircraft, thereby providing opportunities to improve energy efficiency and provide environmentally friendly energy solutions.

[0024] FIG. 1 is a cross-sectional drawing illustrating an example of a method for manufacturing a thermoelectric leg according to an embodiment of the present invention.

[0025] FIG. 2 is a cross-sectional drawing illustrating another example of a method for manufacturing a thermoelectric leg according to an embodiment of the present invention.

[0026] FIG. 3 is a cross-sectional drawing illustrating another example of a method for manufacturing a thermoelectric leg according to an embodiment of the present invention.

[0027] FIG. 4 is a drawing illustrating an example of manufacturing a thermoelectric leg according to an embodiment of the present invention.

[0028] Figure 5 is a drawing comparing the manufacturing cost of a conventional thermoelectric leg and a thermoelectric leg according to an embodiment of the present invention.

[0029] Figure 6 is a diagram comparing the power output and power production unit cost of a conventional thermoelectric leg and a thermoelectric leg according to an embodiment of the present invention.

[0030] FIG. 7 is a drawing illustrating a thermoelectric leg according to an embodiment of the present invention that further includes a hollow closing or insertion spacer.

[0031] FIG. 8 and FIG. 9 are graphs showing the manufacturing cost, power generation cost, and power generation amount of the conventional thermoelectric leg described above and the thermoelectric leg according to the embodiment of the present invention.

[0032] Figure 10 illustrates a method for calculating the β value, which is a parameter related to the generation cost of a thermoelectric leg.

[0033] Figure 11 shows the unit cost of power generation according to β.

[0034] Figure 12 is a diagram showing various shapes of thermoelectric legs and the influence of the β value accordingly.

[0035] Figure 13 is a diagram including graphs showing the electrical resistance of different thermoelectric unit couple devices.

[0036] Figure 14 is a diagram showing the results of measuring the temperature difference between a high temperature part and a low temperature part according to the input heat amount (Q_in) of various thermoelectric unit couple devices.

[0037] Figure 15 is a diagram showing the results of measuring the power production (P_out) according to the input heat amount (Q_in) for various thermoelectric unit couple devices.

[0038] Figure 16 is a diagram showing the relative weights of other thermoelectric unit couple devices normalized based on the 'FF (β = 1.0)' type.

[0039] Figure 17 is a diagram showing the power production per thermoelectric unit couple device normalized to unit weight based on the 'FF (β = 1.0)' type.

[0040] Figure 18 is a diagram comparing the unit cost per unit volume ($ / cm^3) of p-type (Bi_0.5Sb_1.5Te_3) and n-type (Bi_2Te_2.7Se_0.3) legs, which are thermoelectric materials, with the unit cost of glass fabric and NaCl, which are support materials.

[0041] Figure 19 is a diagram showing the normalized power generation cost ($ / W) of a thermoelectric unit couple device based on the 'FF (β = 1.0)' type.

[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The present invention may be modified in various ways and may take various forms. Therefore, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, but should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing each drawing, similar reference numerals are used to indicate similar components. In the attached drawings, the dimensions of structures are shown larger than actual size to ensure clarity of the present invention.

[0043] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, or combinations thereof. In the context of this specification, the term "about" or the like can mean about ± 1%, about ± 2%, about ± 3%, about ± 4%, about ± 5%, about ± 6%, about ± 7%, about ± 8%, about ± 9%, or about ± 10% of a numerical value described in the specification.

[0044] Additionally, the description of one aspect of the present invention may be applied identically or similarly to the same or similar configurations or terms in the description of other aspects.

[0045] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0046] A thermoelectric leg according to an embodiment of the present invention may include a semiconductor and at least one hollow formed in the semiconductor. By configuring the thermoelectric leg as described above, the leg can be lightweight and have improved efficiency. Including the hollow reduces the amount of material used and the energy required during the manufacturing process, which has the potential to reduce overall manufacturing costs. Furthermore, this structure can help optimize the thermal and electrical conductivity of the thermoelectric element, thereby enhancing its performance.

[0047] In the context of this specification, a thermoelectric device refers to a device that generates electrical energy using a temperature difference. Such devices can help convert waste heat into useful electrical energy in various environments. For example, they can convert heat generated in industrial facilities or vehicles into electricity, thereby increasing energy efficiency and reducing environmental impact. Furthermore, improvements in these thermoelectric devices can contribute to improving the efficiency of energy harvesting and management systems in consumer electronics. In particular, the novel structures and manufacturing methods proposed herein offer the potential to reduce the size and weight of the devices while maintaining or improving performance. This could benefit not only portable electronic devices and wearable technology, but also remote areas with limited energy resources and space exploration equipment.

[0048] In the context of this specification, the term "hollow" refers to a space or hole formed within a thermoelectric leg. This hollow structure can help reduce the amount of material used within the device, reduce weight, and optimize thermal and electrical properties. This structural modification can improve device performance while increasing energy efficiency during manufacturing, contributing to overall cost savings. Furthermore, devices containing hollows can provide improved thermal management and electrical conductivity, which can be particularly advantageous for devices operating in high-temperature or extreme environments.

[0049] As long as the above-described function is performed, the manner in which the hollow is formed is not particularly limited. In one embodiment, the hollow may penetrate the side surface of the thermoelectric leg. In one embodiment, the hollow may be formed and closed within the thermoelectric leg. In one embodiment, the hollow may penetrate the thermoelectric leg vertically. By forming the hollow as described above, the thermoelectric leg can optimize its thermal and electrical characteristics in various directions. These various hollow structures can be customized according to the size and shape of the device, thereby providing a design and performance suitable for a specific application. For example, it is possible to manufacture thermoelectric devices suitable for electronic devices requiring miniaturization or devices operating in high-temperature environments. Furthermore, this structural diversity increases flexibility in the manufacturing process and can help develop thermoelectric devices suitable for various environmental conditions and applications.

[0050] In particular, in one embodiment, when the hollow is formed to vertically penetrate the thermoelectric leg, the thermoelectric leg may further include an insertion spacer positioned within the hollow. The insertion spacer may provide electrical or mechanical compensation. This structural improvement helps the device maintain its performance even under extreme environments or high mechanical stress. Furthermore, this design allows the thermoelectric device to operate efficiently over a wider temperature range and in various operating environments, thereby expanding its applicability. The insertion spacer may also optimize the flow and distribution of materials during the manufacturing process of the thermoelectric device, making the manufacturing process more efficient and economical. This can be an important factor in increasing the commercial applicability of the thermoelectric device.

[0051] As long as it performs the above function, the specific shape of the insert spacer is not particularly limited. In one embodiment, the insert spacer may be formed in a tubular shape including a sub-hollow extending vertically through the insert spacer. In one embodiment, the insert spacer may be formed in an I-beam shape having an I-shaped cross-section. Various shapes of the insert spacer provide various possibilities according to the performance and application of the thermoelectric device. The tubular insert spacer may include a sub-hollow to provide additional thermal management and structural support. This shape may help optimize the heat flow within the thermoelectric device and maintain uniform electrical characteristics. The I-beam shaped insert spacer may also provide strong mechanical support and stability, which may enable the device to better withstand physical stress, which may be particularly advantageous in applications where mechanical stability is important.

[0052] In one embodiment, the insert spacer may have the same height as the hollow. This can help improve the overall structural consistency and performance of the thermoelectric leg. This structure can enhance the stability and efficiency of overall performance. Furthermore, by having the insert spacer and hollow having the same height, the mechanical strength and rigidity within the device are balanced, thereby improving the durability and reliability of the device.

[0053] In one embodiment, the semiconductor may include one or more semiconductor materials selected from the group consisting of BiTeSe, BiSbTe, Bi2Te3, PbTe, SiGe, GeTe, Sb2Te3, AgSbTe2, Cu2Se, InSb, MgSi, and Zn2Sb, but these are non-limiting examples and the scope of the present invention is not limited thereto. Each of these semiconductor materials has unique thermoelectric properties and can be selectively used depending on specific applications or operating conditions. This can help customize thermoelectric devices to suit various environments and requirements, and makes a significant contribution to maximizing efficiency and performance.

[0054] Meanwhile, a thermoelectric element according to an embodiment of the present invention may include: a plurality of p-type and n-type thermoelectric legs; a plurality of conductors in contact with at least a portion of the p-type and n-type thermoelectric legs; a first electrode in contact with at least a portion of the conductors; and a second electrode in contact with at least a portion of the conductors and spaced apart from the first electrode. In one embodiment, at least a portion of the thermoelectric legs may be thermoelectric legs according to the embodiment of the present invention described above.

[0055] Meanwhile, a method for manufacturing a thermoelectric leg according to an embodiment of the present invention includes a basic sintering step of sintering a powder of a soluble material or a powder of a semiconductor material by a hot press process in a mold; and an additional sintering step of performing a process of additionally sintering the sintered solid and the powder of the soluble material or the powder of the semiconductor material by a hot press process in another mold at least once to form a sintered solid for dissolution containing both the soluble material and the semiconductor material; and a hollow formation step of selectively removing the soluble material from the sintered solid for dissolution by exposing it to a solvent to form a hollow.

[0056] The above-mentioned basic sintering step forms the core solid, which serves as the foundation for the thermoelectric leg manufacturing process. In this step, the basic structure of the thermoelectric element is formed by sintering powder of a soluble or semiconductor material through a pressing process. In the additional sintering step, in addition to the solid formed in the basic sintering step, another type of soluble or semiconductor material is additionally sintered to create a composite structure. This process is necessary to meet the complex structural requirements of the thermoelectric element and achieve specific thermoelectric properties. Finally, in the hollow formation step, the soluble material formed in the sintered solid for dissolution is selectively removed by exposing it to a solvent, thereby forming a hollow.

[0057] In one embodiment, the press process may be a Spark Plasma Sintering (SPS) process. In the context of this specification, the SPS process is a process of applying pressure, voltage, and current to a sintered body to sinter it, and refers to a method of rapidly sintering powdered materials using high pressure and temperature. This process can help optimize the structural properties and electrical performance of thermoelectric devices by forming a uniform density and strong bond within the material. The fast sintering speed of the SPS process increases production efficiency and reduces the risk of deformation or damage that the material may experience at high temperatures, which can contribute to reducing overall manufacturing costs and improving product quality. Furthermore, the SPS process can be applied to the sintering of various types of materials and composite materials, and thus can play a significant role in expanding the performance and application range of thermoelectric devices.

[0058] As described above, as long as the hollow performs the function described above, the manner in which the hollow is formed is not particularly limited, and the soluble material may be placed and sintered according to the desired hollow. In one embodiment, the soluble material may be placed so that the hollow formed in the hollow forming step penetrates the side surface of the thermoelectric leg. In one embodiment, the soluble material may be placed so that the hollow formed in the hollow forming step is closed inside the thermoelectric leg. However, in one embodiment, when the soluble material is placed so that the hollow is closed inside the thermoelectric leg, the portion where the powder of the semiconductor material is sintered may have one or more holes formed so that the soluble material is exposed to the solvent. In one embodiment, the sintered solid forming step may perform the additional sintering step two or more times so that the solid in which the semiconductor material is sintered is inserted into the portion where the soluble material is sintered.

[0059] FIG. 1 is a cross-sectional view illustrating an example of a method for manufacturing a thermoelectric leg according to an embodiment of the present invention. In FIG. 1, light gray represents a soluble material, and dark gray represents a semiconductor material, and the same applies to the following drawings. The example in FIG. 1 is a method for simply manufacturing a hollow cell. As shown in the left drawing, a core of a soluble material is formed in a basic sintering step, and then, as shown in the center drawing, a semiconductor material surrounding the core is formed in an additional sintering step. Finally, as shown in the right drawing, the soluble material is removed by exposing it to a solvent, thereby manufacturing a hollow cell.

[0060] In one embodiment, the sintered solid of the semiconductor material can be formed into a tubular or I-beam shape.

[0061] FIG. 2 is a cross-sectional view illustrating another example of a method for manufacturing a thermoelectric leg according to an embodiment of the present invention. The example in FIG. 2 illustrates a method for manufacturing a cell with an additional tubular insert spacer inserted therein. From the left, after sintering a core with a soluble material, a semiconductor material completely surrounding the core can be formed, followed by another soluble material surrounding the core, and finally, another semiconductor material completely surrounding the core. In this state, when the soluble material is removed by exposing it to a solvent, a tubular insert spacer is formed within the semiconductor, allowing the manufacturing of a cell with improved mechanical properties. Depending on the purpose, the sintered solid may be pre-fixed to an electrode or substrate before removing the soluble material.

[0062] Referring partially to Figure 2, the tubular insert spacer may be a pre-formed rigid body. A soluble material may be placed inside the tubular spacer, sintered, and the sintered shape may be wrapped with a thermoelectric material (semiconductor material). In this case, the tubular insert spacer can be formed without a sintering process.

[0063] FIG. 3 is a cross-sectional view illustrating another example of a method for manufacturing a thermoelectric leg according to an embodiment of the present invention. The example of FIG. 3 is a method for manufacturing a cell with an additional I-beam-shaped insertion spacer inserted therein. From the left, after sintering a core with a semiconductor material, a soluble material is added to both sides, a semiconductor material is added to the other orthogonal sides, a soluble material is added to surround the entire structure, and finally, a semiconductor material is added to surround the entire structure again. In this state, when the soluble material is removed by exposing it to a solvent, an I-beam-shaped insertion spacer is formed within the semiconductor, allowing the manufacture of a cell with improved mechanical properties. Depending on the purpose, the sintered solid may be fixed to an electrode or substrate in advance before removing the soluble material.

[0064] Referring partially to Fig. 3, the I-beam shaped insert spacer may be a pre-formed rigid body. A soluble material may be placed around the I-beam shaped spacer, sintered, and then the sintered shape may be wrapped with a thermoelectric material (semiconductor material). In this case, the I-beam shaped insert spacer may be formed without a sintering process.

[0065] The insertion spacers mentioned in FIGS. 2 and 3 do not necessarily have to be formed of semiconductors, but instead can be made of pre-formed rigid bodies. These insertion spacers can be made of materials that not only have high strength and rigidity, but also low thermal conductivity and coefficient of thermal expansion. This can play a significant role in enhancing the structural stability and performance of the thermoelectric device. Non-limiting examples include materials such as glass fabric, which can help optimize the thermal and electrical properties within the thermoelectric device. The use of materials such as glass fabric can enable the thermoelectric device to operate stably even in extreme environments, and can provide long-term durability and reliability.

[0066] The examples described above are illustrative of specific shapes and materials of the insert spacer, and the structure, shape and material of the insert spacer inserted into the hollow are not limited thereto, as long as they provide electrical or mechanical compensation.

[0067] As long as the above-described function is performed, the material of the soluble substance is not particularly limited. In one embodiment, the soluble substance may include sodium chloride (NaCl). This is a non-limiting example, but the soluble substance that can be used in the present invention may have high solubility in a specific solvent and may be easily sintered during the process. Because sodium chloride is highly soluble, it can be easily removed during the hollow-forming process, which enables the precise manufacturing of thermoelectric legs with complex structures. Through this sintering and hollow-forming process, the weight of the thermoelectric device can be reduced, manufacturing costs can be reduced, and efficiency can be improved. Furthermore, it is possible to use soluble substances other than NaCl, which can add flexibility to the manufacturing process and help develop devices suitable for various environmental conditions and applications.

[0068] Hereinafter, embodiments of the present invention will be described. However, the embodiments described below are merely some embodiments of the present invention, and the scope of the present invention is not limited to the embodiments described below.

[0069] Manufacturing example

[0070] FIG. 4 is a drawing illustrating an example of manufacturing a thermoelectric leg according to an embodiment of the present invention. Referring to FIG. 4, the manufacturing example is described as follows: as in No. 1, NaCl is sintered in a mold to form a core, and as in No. 2, n-type or p-type semiconductor powder is filled around the core and then sintered again. The sintering is performed using the SPS process, and the conditions of the SPS process are as follows: the pressure is 50.0 MPa, the temperature is 450.0 °C, and the time range is set to 10-10 minutes. As semiconductor materials used in the manufacturing process, BiTeSe is selected as the n-type semiconductor, and BiSbTe is selected as the p-type semiconductor. These materials are used to form the n-type and p-type legs of the thermoelectric device, respectively. In addition, NaCl is used, and its purity is selected to be 99%. NaCl is a soluble substance used to form a hollow, and by removing it by exposing it to a solvent after the sintering process, as in No. 3, it contributes to creating a precise space within the thermoelectric device. Through this manufacturing process, a thermoelectric leg with high efficiency and light weight can be produced.

[0071] Comparison of production and power generation costs

[0072] Figure 5 is a drawing comparing the manufacturing cost of a conventional thermoelectric leg and a thermoelectric leg according to an embodiment of the present invention. As shown in the lower part of Figure 5, the p-type semiconductor as the thermoelectric material is Bi. 0.5 Sb 1.5 Te 3.0 , n-type semiconductor is Bi 2.0 Te 2.7 Se 0.3 , and the unit prices of Bi, Ti, Se, Sb, and NaCl were set at 2.430, 2.607, 5.185, 0.105, and 0.002 (unit price), respectively. As shown in the upper part of Fig. 5, the unit price of the conventional thermoelectric leg is 5.791, but the unit price of the thermoelectric leg according to the embodiment of the present invention is 3.221, which is 44.4% less than that of the conventional technology.

[0073] Fig. 6 is a diagram comparing the power output and power generation cost of a conventional thermoelectric leg and a thermoelectric leg according to an embodiment of the present invention. Conv represents a conventional thermoelectric leg as shown on the left side of Fig. 5, NaCl_1 represents a thermoelectric leg with a hollow formed vertically as shown in the middle of Fig. 5, and NaCl_2 represents a thermoelectric leg with a hollow formed penetrating the side as shown on the right side of Fig. 5. In the case of the NaCl_1 structure, the manufacturing cost was the lowest, and the performance was the best, and it could be confirmed that the power generation cost was reduced by 54.7% compared to the conventional structure. In the case of the NaCl_2 structure, the power generation performance was similar to that of the conventional shape (conv), but the manufacturing cost was significantly reduced, resulting in a power generation cost reduction of 41.8% compared to the conventional structure.

[0074] FIG. 7 is a diagram illustrating a cell for a thermoelectric element leg according to an embodiment of the present invention that further includes a closed hollow or an insert spacer. Referring to FIG. 7, embodiments of the present invention may include a closed hollow to improve electrical properties, or a tubular or I-beam-shaped insert spacer to improve mechanical properties. The closed hollow shape can increase the contact area between the thermoelectric leg and the electrode, thereby reducing electrical resistance, which can help improve electrical properties. On the other hand, embodiments that use a tubular or I-beam-shaped insert spacer serve to increase the mechanical strength and rigidity of the thermoelectric element. Such an insert spacer can help the thermoelectric element operate stably under various environmental conditions and contribute to improved durability. The external and internal dimensions (5.3(A) x 10.0(H) mm / 3.4(A) x 10.0(H) mm / 2.4(A) x 10.0(H) mm) and β value (0.54) presented in Fig. 7 can be important references for evaluating what effect this design actually has.

[0075] FIGS. 8 and 9 are graphs illustrating the manufacturing cost, power generation cost, and power generation amount of the conventional thermoelectric leg described above and the thermoelectric leg according to an embodiment of the present invention. The notations in the drawings are as in FIG. 7: Fully filled means a conventional thermoelectric leg, Hollow means a cell formed only with a penetrating hollow, Closed air means a closed cell, Spacer Inserted Hollow means a cell formed with a tubular insert spacer, and I-Beam Inserted means a cell formed with an I-beam-shaped insert spacer. Referring to FIGS. 8 and 9, although thermoelectric elements with hollow and closed air structures exhibit excellent performance in terms of power generation cost, they have a problem in that they are difficult to apply to actual designs due to the weakness of mechanical strength and rigidity. To solve this problem, a method of inserting a spacer made of a material that can reinforce mechanical properties inside (Spacer Inserted Hollow, I-Beam Inserted) is proposed. This spacer insertion can enhance the structural integrity of thermoelectric elements while also increasing their strength and rigidity, thereby addressing the weaknesses of hollow and closed structures. In particular, the "Spacer Inserted Hollow" design, which exhibits the highest structural integrity, offers the potential to further reduce power generation costs by designing the thermoelectric element thinner. This approach can enhance the practicality of thermoelectric elements and improve their economic viability for large-scale production and commercial applications.

[0076] Fig. 10 illustrates a method for calculating the β value, which is a parameter related to the unit cost of generation of a thermoelectric leg. Fig. 11 illustrates the unit cost of generation according to β. Referring to Figs. 10 and 11 together, the fact that the effect of reducing the unit cost of generation ($ / W) increases as the thickness (β) of the thermoelectric element decreases has an important meaning. According to the prior art, the performance when the β value is 0.54 was the standard. However, in the case of the Spacer Inserted Hollow and I-Beam Inserted shapes, it was confirmed that the structural integrity was the best in the Spacer Inserted Hollow shape in particular. This means that it is possible to further reduce the β value of the thermoelectric element, which in turn suggests that the unit cost of generation can be further reduced.

[0077] marketability

[0078] Thermoelectric generators manufactured using this method can be manufactured using existing process equipment, and are expected to significantly reduce the unit cost of power generation. This reduction has the potential to accelerate the commercialization of thermoelectric devices, which can be widely utilized in various industrial sectors. In particular, this device, which can generate electricity using temperature differences, can be used as a waste heat recovery system in waste heat generation facilities such as automobiles, ships, and power plants, thereby helping reduce carbon emissions through energy recycling. Furthermore, it can be applied to a variety of advanced technologies, such as space generators, aircraft thermal control systems, military infrared detectors, missile coolers, and medical thermostats and blood storage systems, significantly expanding the scope and efficiency of these technologies. These diverse applications can significantly contribute to the innovation of thermoelectric technology and the development of sustainable energy solutions.

[0079]

[0080] Figure 12 is a diagram showing various thermoelectric leg shapes and the effect of β value accordingly. β value represents the material volume ratio of the thermoelectric leg, which is one of the important factors that determines the power generation cost of a thermoelectric device. This diagram presents four thermoelectric leg shapes: 'FF (Fully Filled),' 'Hollow,' 'SI (Support Inserted),' and 'HSI (Hollow Support Inserted).' Referring to Figure 12, from the fully filled FF shape to the hollow shape with an interior, the SI shape with an interior support inserted, and the HSI shape with a hollow interior and a support inserted, it can be seen that as the β value decreases, the amount of thermoelectric material required decreases, thereby reducing material costs. This demonstrates the possibility of reducing the power generation cost. In particular, the SI shape with an interior filled with an insulating material such as glass fabric and the HSI shape with an interior space and an inserted support are effective in reducing material usage while maintaining mechanical strength and lowering the power generation cost. Such structural modifications can lower the cost of power generation while enhancing the reliability and durability of thermoelectric elements.

[0081] Fig. 13 is a diagram including a graph showing the electrical resistance of different thermoelectric unit couple devices. This graph compares the electrical resistance values ​​according to various thermoelectric leg shapes, namely 'FF (β=1.0)', 'Hollow (β=0.8, 0.6, 0.4)', 'SI (β=0.2)', and 'HSI (β=0.2)'. Referring to Fig. 13, it can be confirmed that the 'FF' shape, which is a fully filled shape, shows the lowest electrical resistance value, and the 'Hollow' units with a hollow structure show a tendency for the electrical resistance to increase as the β value decreases.

[0082] Figure 14 is a diagram showing the results of measuring the temperature difference between the high temperature and low temperature sections according to the input heat amount (Q_in) of various thermoelectric unit couple devices. The experimental results are represented by dots, and the ANSYS simulation results are represented by lines. Referring to Figure 14, it can be seen that the fully filled 'FF (β = 1.0)' shape shows the lowest temperature difference, while the 'Hollow_0.4 (β = 0.4)' and 'HSI (β = 0.2)' shapes show significantly higher temperature differences compared to the FF.

[0083] Fig. 15 is a diagram showing the results of measuring the power production (P_out) according to the input heat amount (Q_in) for various thermoelectric unit couple devices. The experimental results are represented by dots, and the ANSYS simulation results are represented by lines. Referring to Fig. 15, it can be confirmed that the 'Hollow_0.4 (β = 0.4)' type shows a higher power output than the FF. This can be interpreted as the effect of the increase in temperature difference overwhelming the effect of the increase in electrical resistance, thereby increasing the power output. On the other hand, in the 'SI (β = 0.2)' and 'HSI (β = 0.2)' types, even though the temperature difference increases, the increase in electrical resistance has a greater effect, tending to decrease the power output.

[0084] Fig. 16 is a diagram showing the relative weight of other thermoelectric unit couple devices normalized based on the 'FF (β = 1.0)' type. This graph shows the weight ratio according to each thermoelectric leg type. Referring to Fig. 16, the 'FF' type is the heaviest, and the weight of the 'Hollow' type thermoelectric legs decreases according to the β value. In the case of 'SI (β = 0.2)' and 'HSI (β = 0.2)', the weight of the thermoelectric material decreases, but the decrease is offset by the weight of the supporter. This indicates that it can be advantageous in applications that require both high performance and lightweight.

[0085] Fig. 17 is a diagram showing the power generation per unit weight of each thermoelectric unit couple device based on the 'FF (β = 1.0)' type. The data represented by dots are calculated values ​​based on experiments, and are a comparative analysis of the performance of thermoelectric units with different β values. Referring to Fig. 17, the 'Hollow_0.4 (β = 0.4)' type shows the highest power generation per weight, and the 'FF' and 'HSI (β = 0.2)' types show lower values. This result shows that power generation efficiency can be increased while reducing weight, suggesting that power generation can be increased while reducing the impact on fuel efficiency and load weight when applied to vehicles or ships.

[0086] Figure 18 is a diagram comparing the unit volume cost ($ / cm^3) of p-type (Bi_0.5Sb_1.5Te_3) and n-type (Bi_2Te_2.7Se_0.3) thermoelectric materials with the unit costs of glass fabric and NaCl as support materials. Referring to Figure 18, it can be seen that the unit costs of p-type and n-type thermoelectric materials are significantly higher than those of glass fabric and NaCl. In particular, the unit cost of the n-type thermoelectric material is the highest, suggesting that a design that minimizes the amount of thermoelectric material used plays an important role in reducing the unit cost of the overall thermoelectric device. Glass fabric is relatively inexpensive but provides structural support and insulation, whereas NaCl can be used at a very low cost.

[0087] Fig. 19 is a diagram showing the normalized power generation cost ($ / W) of the thermoelectric unit couple device based on the 'FF(β=1.0)' type. The values ​​indicated by dots represent data calculated based on experiments. Referring to Fig. 19, the 'Hollow_0.4(β=0.4)' type shows the lowest power generation cost, and it can be confirmed that the 'HSI(β=0.2)' type also enables a significant power generation cost reduction compared to the 'FF' type. This data indicates that the structural improvement of the thermoelectric element to minimize the power generation cost is effective. 'Hollow_0.4' shows that the power generation cost can be reduced by about 79 to 83% compared to the 'FF' type, and 'HSI' shows that the power generation cost can be reduced by about 71 to 76%.

[0088] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. Contains semiconductors, comprising at least one hollow formed in the semiconductor, Thermal leg.

2. In paragraph 1, The above hollow penetrates the side of the above thermoelectric leg, Thermal leg.

3. In paragraph 1, The above hollow is formed and closed inside the thermoelectric leg, Thermal leg.

4. In paragraph 1, The above hollow penetrates the above thermoelectric legs upward and downward, Thermal leg.

5. In paragraph 3, The above thermoelectric leg further includes an insert spacer positioned within the hollow, Thermal leg.

6. In paragraph 5, The above insertion spacer is formed in a tubular shape including a sub-hollow penetrating the insertion spacer upward and downward. Thermal leg.

7. In paragraph 5, The above insertion spacer is formed in an I-beam shape with an I-shaped cross section. Thermal leg.

8. In paragraph 6 or 7, The above insertion spacer has the same height as the above hollow, Thermal leg.

9. In paragraph 1, The semiconductor comprises at least one semiconductor material selected from the group consisting of BiTeSe, BiSbTe, Bi2Te3, PbTe, SiGe, GeTe, Sb2Te3, AgSbTe2, Cu2Se, InSb, MgSi, and Zn2Sb. Thermal leg.

10. Multiple p-type and n-type thermoelectric legs; A plurality of conductors in contact with at least a portion of the p-type and n-type thermoelectric legs; a first electrode in contact with at least a portion of the conductor; and a second electrode in contact with at least a portion of the conductor and spaced apart from the first electrode; At least some of the above thermoelectric legs are thermoelectric legs according to claim 1, Thermoelectric element.

11. A sintered solid formation step, comprising: a basic sintering step of sintering a powder of a soluble substance or a powder of a semiconductor substance by a hot press process within a mold; and an additional sintering step of performing a process of additionally sintering the sintered solid and the powder of the soluble substance or the powder of the semiconductor substance by a hot press process within another mold at least once to form a sintered solid for dissolution containing both the soluble substance and the semiconductor substance; and A hollow forming step comprising: selectively removing the soluble material from the sintered solid for dissolution by exposing it to a solvent to form a hollow; Method for manufacturing a thermoelectric leg.

12. In paragraph 11, The soluble material is placed so that the hollow formed in the hollow forming step penetrates the side of the thermoelectric leg. Method for manufacturing a thermoelectric leg.

13. In paragraph 11, The soluble material is placed so that the hollow formed in the hollow formation step is closed inside the thermoelectric leg, The sintered portion of the above semiconductor material powder has one or more holes formed so that the soluble material is exposed to the solvent. Method for manufacturing a thermoelectric leg.

14. In paragraph 11, The above sintering solid formation step forms a sintering solid for melting while placing an insert spacer inside. Method for manufacturing a thermoelectric leg.

15. In paragraph 11, The semiconductor material comprises at least one semiconductor material selected from the group consisting of BiTeSe, BiSbTe, Bi2Te3, PbTe, SiGe, GeTe, Sb2Te3, AgSbTe2, Cu2Se, InSb, MgSi, and Zn2Sb. Method for manufacturing a thermoelectric leg.

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