Thermoelectric element and refrigerator including same

Abstract

A method for manufacturing a thermoelectric element according to an embodiment disclosed herein may comprise: a step for preparing a Bi-Te-based alloy material, wherein the Bi-Te-based alloy material contains 0.1-0.5 mol% of selenium on the basis of the total number of moles; a step for primarily pulverizing the Bi-Te-based alloy material, wherein the Bi-Te-based alloy material is pulverized through a gap of 1-5 mm, set between a pair of pulverizing plates, to form alloy pieces each having a first length; and a step for secondarily pulverizing the primarily pulverized alloy pieces, wherein the alloy pieces are pulverized through a gap of 0.1-10 mm, set between a pair of disks, to form plate-shaped alloy powder particles having a second length smaller than the first length.

Description

Thermoelectric element and refrigerator including the same

[0001] One embodiment disclosed in this document relates to a thermoelectric element and a refrigerator including the same.

[0002] In general, thermoelectric devices are referred to by various names such as thermoelectric modules, Peltier elements, thermoelectric coolers (TECs), or thermoelectric modules (TEMs). Thermoelectric devices consist of N-type and P-type thermoelectric materials (thermoelectric legs) and electrodes such as nickel (Ni) and cobalt (Co).

[0003] When a direct current (DC) voltage is applied to both ends of a thermoelectric element, heat moves from the heat-absorbing part to the heat-generating part according to the flow of electrons in N-type thermoelectric materials and according to the flow of holes in P-type thermoelectric materials. In some cases, if the polarity of the applied voltage is changed, the positions of the heat-absorbing part and the heat-generating part are reversed, and the heat flow is also reversed. Through this principle, the thermoelectric element can serve as a heat pump that absorbs heat from a low-temperature heat source and supplies it to a high-temperature heat source, or as a thermoelectric generator (TEG) that generates an electromotive force by moving electrons and holes inside the thermoelectric element due to the temperature difference between the two ends.

[0004] As the demand for thermoelectric devices increases, there is a growing need for thermoelectric materials with excellent thermoelectric performance (e.g., Seebeck coefficient, electrical conductivity, thermal conductivity, and mobility).

[0005] A method for manufacturing a thermoelectric element according to one embodiment of the present disclosure may include a process for preparing a Bi-Te alloy material, wherein the Bi-Te alloy material contains selenium in a range of 0.1 to 0.5 mol.% based on total molar amount; a process for first crushing the Bi-Te alloy material, wherein the Bi-Te alloy material is crushed through a gap of 1 mm to 5 mm set between a pair of crushing plates to form an alloy piece having a first length; and a process for second crushing the first crushed alloy piece, wherein the alloy piece is crushed through a gap of 0.1 mm to 10 mm set between a pair of discs to form a plate-shaped alloy powder having a second length smaller than the first length.

[0006] A refrigerator according to one embodiment of the present disclosure may include a main body, a door rotatably connected to open and close the main body, a storage compartment disposed inside the main body for storing food, and a cold air supply device configured to supply cold air to the storage compartment and including a thermoelectric element (100). The thermoelectric element includes a Bi-Te-based thermoelectric leg, and the Bi-Te-based thermoelectric leg may contain selenium (Se) in a range of 0.1 to 0.5 mol.% based on the total molar amount. The Bi-Te-based thermoelectric leg is a sintered body composed of plate-shaped alloy powders, and the length of each of the plate-shaped alloy powders for forming the sintered body may be 200 μm or less.

[0007] The thermoelectric element according to one embodiment of the present disclosure may include a Bi-Te-based thermoelectric leg. The Bi-Te-based thermoelectric leg may contain selenium (Se) in a range of 0.1 to 0.5 mol.% based on the total molar amount. The Bi-Te-based thermoelectric leg (110) is a sintered body composed of plate-shaped alloy powders, and the length of each of the plate-shaped alloy powders for forming the sintered body may be 200 μm or less.

[0008] The present disclosure is not limited to the problems mentioned above and may be modified in various ways without departing from the spirit and scope of the present disclosure.

[0009] These and / or other aspects will become clearer and more easily understood from the description of the embodiments considered together with the accompanying drawings listed below.

[0010] FIG. 1 is a perspective view showing the structure of a thermoelectric element according to one embodiment of the present disclosure.

[0011] FIG. 2 is a schematic diagram showing the process of forming an N-type thermoelectric element according to one embodiment of the present disclosure.

[0012] FIGS. 3a to 3c are drawings showing an apparatus for a secondary crushing process during the formation process of an N-type thermoelectric element according to one embodiment of the present disclosure.

[0013] FIG. 4 is a flowchart showing the process of forming an N-type thermoelectric element according to one embodiment of the present disclosure.

[0014] FIG. 5 is a drawing showing an alloy piece after primary crushing during the formation process of an N-type thermoelectric element according to one embodiment of the present disclosure.

[0015] FIG. 6 is a diagram showing alloy powder after secondary grinding during the formation process of an N-type thermoelectric element according to one embodiment of the present disclosure.

[0016] FIG. 7 is a diagram showing a structure in which plate-shaped alloy powder is formed in a process of forming an N-type thermoelectric element according to one embodiment of the present disclosure.

[0017] FIG. 8a is an enlarged view of a portion of a sintered body that has undergone a sintering process after grinding, according to one embodiment of the present disclosure.

[0018] FIG. 8b is a drawing showing the shape and thermal conductivity of alloy powder crushed by equipment according to one embodiment of the present disclosure.

[0019] FIG. 9 is a diagram showing the power factor (PF) according to the size of the alloy powder according to one embodiment of the present disclosure.

[0020] Figure 10a is a diagram showing the shape of the powder and EBSD (electron backscatter diffraction) by a general mechanical alloying method.

[0021] FIG. 10b is a diagram showing the shape of a powder and electron backscatter diffraction (EBSD) by multiple grinding steps according to one embodiment of the present disclosure.

[0022] FIG. 11 is a perspective view of a refrigerator according to one embodiment of the present disclosure.

[0023] The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of said embodiments.

[0024] In relation to the description of the drawings, similar reference numerals may be used for similar or related components.

[0025] The singular form of the noun corresponding to the item may include one or multiple items, unless the relevant context clearly indicates otherwise.

[0026] In this document, each of the phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "at least one of A, B, or C" may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0027] In this document, the term “and / or” includes a combination of multiple related described components or any of the multiple related described components.

[0028] In this document, terms such as "first," "second," or "first" or "second" may be used simply to distinguish a component from another component and do not limit the components in any other aspect (e.g., importance or order).

[0029] In this document, terms such as "front," "rear," "top," "bottom," "side," "left," "right," "top," and "bottom" are defined based on the drawings, and the shape and location of each component are not limited by these terms.

[0030] Where any (e.g., 1st) component is referred to as "coupled" or "connected" to another (e.g., 2nd) component, with or without the terms "functionally" or "communicationly," it means that said any component may be connected to said other component directly (e.g., via a wire), wirelessly, or through a third component.

[0031] Terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this document, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0032] When it is said that a component is "connected," "combined," "supported," or "in contact" with another component, this includes not only cases where the components are directly connected, combined, supported, or in contact, but also cases where they are indirectly connected, combined, supported, or in contact through a third component.

[0033] When it is said that a component is located "on" another component, this includes not only cases where one component is in contact with the other, but also cases where another component exists between the two components.

[0034] A refrigerator according to one embodiment may include a main body.

[0035] The "main body" may include an inner body, an outer body positioned on the outside of the inner body, and an insulating material provided between the inner body and the outer body.

[0036] The "inner body" may include at least one of a case, plate, panel, or liner forming a storage chamber. The inner body may be formed as a single body or may be formed by assembling multiple plates. The "outer body" may form the exterior of the main body and may be coupled to the outer side of the inner body so that an insulating material is disposed between the inner body and the outer body.

[0037] The "insulating material" can insulate the interior and exterior of the storage room so that the temperature inside the storage room is maintained at a set appropriate temperature without being affected by the external environment. According to one embodiment, the insulating material may include a foamed insulating material. The foamed insulating material can be formed by injecting and foaming urethane foam, which is a mixture of polyurethane and a foaming agent, between the inner and outer layers.

[0038] According to one embodiment, the insulation material may additionally include a vacuum insulation material in addition to a foam insulation material, or the insulation material may consist solely of a vacuum insulation material instead of a foam insulation material. The vacuum insulation material may include a core material and an outer shell material that accommodates the core material and seals the interior under vacuum or near-vacuum pressure. However, the insulation material is not limited to the foam insulation material or vacuum insulation material described above and may include various materials that can be used for insulation.

[0039] The "storage room" may include a space defined by an internal structure. The storage room may further include an internal structure defining a space corresponding to the storage room. Various items such as food, medicine, and cosmetics may be stored in the storage room, and the storage room may be formed so that at least one side is open to allow for the retrieval and retrieval of items.

[0040] A refrigerator may include one or more storage compartments. When two or more storage compartments are formed in a refrigerator, each storage compartment may have a different use and may be maintained at a different temperature. To this end, each storage compartment may be partitioned from one another by a partition containing insulation.

[0041] The storage room may be provided to be maintained within an appropriate temperature range according to its intended use and may include a "refrigeration room," "freezing room," or "variable temperature room" distinguished according to its intended use and / or temperature range. The refrigerator room may be maintained at a temperature appropriate for refrigerated storage of goods, and the freezer room may be maintained at a temperature appropriate for frozen storage of goods. "Refrigeration" may mean cooling goods to a temperature that does not freeze them; for example, the refrigerator room may be maintained within a range of 0°C to 7°C. "Freezing" may mean cooling goods to freeze them or to maintain them in a frozen state; for example, the freezer room may be maintained within a range of -20°C to -1°C. The variable temperature room may be used as either a refrigerator room or a freezer room, with or without the user's choice.

[0042] Storage rooms may be referred to by various names, such as "vegetable room," "fresh room," "cooling room," and "ice-making room," in addition to terms like "refrigeration room," "freezing room," and "variable temperature room." The terms "refrigeration room," "freezing room," and "variable temperature room" used below should be understood as encompassing storage rooms with corresponding uses and temperature ranges.

[0043] According to one embodiment, the refrigerator may include at least one door configured to open and close one side of the storage compartment. The door may be configured to open and close each of one or more storage compartments, or a single door may be configured to open and close multiple storage compartments. The door may be installed to be rotatable or sliding on the front of the main body.

[0044] The “door” may be configured to seal the storage room when the door is closed. The door may include insulation material, similar to the main body, to insulate the storage room when the door is closed.

[0045] According to one embodiment, the door may include a door outer panel forming the front of the door, a door inner panel forming the rear of the door and facing the storage room, an upper cap, a lower cap, and a door insulation material provided inside the same.

[0046] A gasket may be provided on the edge of the door inner panel to seal the storage compartment by adhering to the front of the main body when the door is closed. The door inner panel may include a dyke that protrudes rearward to allow a door basket for storing items to be mounted.

[0047] According to one embodiment, the door may include a door body and a front panel detachably coupled to the front side of the door body and forming the front of the door. The door body may include a door outer panel forming the front of the door body, a door inner panel forming the rear of the door body and facing the storage compartment, an upper cap, a lower cap, and a door insulation material provided inside them.

[0048] Refrigerators can be classified into French Door Type, Side-by-side Type, BMF (Bottom Mounted Freezer), TMF (Top Mounted Freezer), or 1-door refrigerators depending on the arrangement of the door and storage compartment.

[0049] According to one embodiment, the refrigerator may include a cold air supply device arranged to supply cold air to the storage compartment.

[0050] The "cold air supply device" may include a machine, apparatus, electronic device, and / or a system combining these that can generate cold air and guide cold air to cool a storage room.

[0051] According to one embodiment, a cold air supply device can generate cold air through a refrigeration cycle that includes the processes of compression, condensation, expansion, and evaporation of a refrigerant. To this end, the cold air supply device may include a refrigeration cycle device having a compressor, a condenser, an expansion device, and an evaporator capable of driving the refrigeration cycle. According to one embodiment, the cold air supply device may include a semiconductor such as a thermoelectric element. The thermoelectric element can cool a storage chamber through heat generation and cooling action via the Peltier effect.

[0052] According to one embodiment, the refrigerator may include a machine room arranged to accommodate at least some parts belonging to a cold air supply device.

[0053] The "machine room" may be configured to be partitioned and insulated from the storage room to prevent heat generated from components placed in the machine room from being transferred to the storage room. The interior of the machine room may be configured to communicate with the exterior of the main body to dissipate heat from components placed inside the machine room.

[0054] According to one embodiment, the refrigerator may include a dispenser provided on the door to provide water and / or ice. The dispenser may be provided on the door so that it is accessible to a user without opening the door.

[0055] According to one embodiment, the refrigerator may include an ice-making device configured to generate ice. The ice-making device may include an ice-making tray that stores water, an ice-removing device that separates ice from the ice-making tray, and an ice bucket that stores the ice generated from the ice-making tray.

[0056] According to one embodiment, the refrigerator may include a control unit for controlling the refrigerator.

[0057] The "control unit" may include a memory that stores or remembers a program and / or data for controlling a refrigerator, and a processor that outputs a control signal for controlling a cold air supply device, etc., according to the program and / or data stored in the memory.

[0058] The memory stores or records various information, data, commands, programs, etc., necessary for the operation of the refrigerator. The memory can store temporary data generated while generating control signals to control the components included in the refrigerator. The memory may include at least one of volatile memory or non-volatile memory, or a combination thereof.

[0059] The processor controls the overall operation of the refrigerator. The processor can control the components of the refrigerator by executing programs stored in memory. The processor may include a separate NPU that performs the operation of an artificial intelligence model. Additionally, the processor may include a central processing unit, a graphics processing unit (GPU), etc. The processor can generate control signals to control the operation of the cold air supply unit. For example, the processor can receive temperature information of the storage compartment from a temperature sensor and generate a cooling control signal to control the operation of the cold air supply unit based on the temperature information of the storage compartment.

[0060] Additionally, the processor can process user input of the user interface and control the operation of the user interface according to programs and / or data stored in memory. The user interface may be provided using an input interface and an output interface. The processor can receive user input from the user interface. Additionally, the processor can transmit display control signals and image data to the user interface to display an image on the user interface in response to the user input.

[0061] The processor and memory may be provided as a single unit or separately. The processor may include one or more processors. For example, the processor may include a main processor and at least one sub-processor. The memory may include one or more memory units.

[0062] According to one embodiment, the refrigerator may include a processor and memory that control all components included in the refrigerator, and may include a plurality of processors and a plurality of memories that individually control the components of the refrigerator. For example, the refrigerator may include a processor and memory that control the operation of a cold air supply device according to the output of a temperature sensor. Additionally, the refrigerator may separately provide a processor and memory that control the operation of a user interface according to user input.

[0063] The communication module can communicate with external devices, such as servers, mobile devices, and other home appliances, through nearby Access Points (APs). The Access Point (AP) can connect the Local Area Network (LAN) to which the refrigerator or user device is connected to the Wide Area Network (WAN) to which the server is connected. The refrigerator or user device can be connected to the server through the Wide Area Network (WAN).

[0064] The input interface may include keys, touchscreens, microphones, etc. The input interface may receive user input and transmit it to the processor.

[0065] The output interface may include a display, a speaker, etc. The output interface can output various notifications, messages, information, etc. generated by the processor.

[0066] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0067] Meanwhile, terms such as "upward," "downward," "front," and "rear" used in the following description are defined based on the drawings, and the shape and location of each component are not limited by these terms. For example, the terms "front" and "rear" below may refer to the front and rear of the refrigerator in the X-direction, respectively, based on the drawings. The terms "upward" and "downward" below may refer to the upward and downward directions of the refrigerator in the Z-direction, respectively, based on the drawings. The terms "left" and "right" below may refer to the left and right directions of the refrigerator in the Y-direction, respectively, based on the drawings.

[0068] Hereinafter, a thermoelectric semiconductor (hereinafter referred to as a thermoelectric element) used in a cold air supply device will be described. The thermoelectric element is described as a semiconductor for cooling the storage compartment of a refrigerator, but is not limited thereto and can be easily modified in design and applied to various home appliances where thermoelectric elements are utilized, such as air purifiers, robot vacuum cleaners, cooking appliances, or washing machines.

[0069] FIG. 1 is a perspective view showing the structure of a thermoelectric element (100) according to one embodiment of the present disclosure.

[0070] Referring to FIG. 1, the thermoelectric element (100) may include a plurality of thermoelectric legs (110) (e.g., thermoelectric materials), electrodes (200a, 200b), a substrate (300a, 300b), a heat sink (400a), and / or a heat absorber (400b).

[0071] According to one embodiment, the thermoelectric element (100) may include a first substrate (300a), a second substrate (300b) disposed parallel to the first substrate (300a), a first electrode (200a) disposed on the first substrate (300a), a second electrode (200b) disposed on the second substrate (300b), and a thermoelectric leg (110) disposed between the first electrode (200a) and the second electrode (200b). The first electrode (200a) and the second electrode (200b) may be disposed between the first substrate (300a) and the second substrate (300b). The first electrode (200a) and the second electrode (200b) may form a designated pattern and may be arranged in a plurality.

[0072] According to one embodiment, the first substrate (300a) and the second substrate (300b) can each generate an exothermic or endothermic reaction when power is applied to the thermoelectric element (100). The first substrate (300a) and the second substrate (300b) can each be formed in the shape of a plate and made of various materials. According to one embodiment, the first substrate (300a) and / or the second substrate (300b) can be formed of a non-conductive material such as ceramic or insulating resin. For example, the first substrate (300a) and / or the second substrate (300b) can be composed of one or a combination of Al2O3, AlN, SiC, or ZrO2. According to one embodiment, the first substrate (300a) and / or the second substrate (300b) can be substrates of a conductive material capable of conducting electricity (e.g., metal). For example, the first substrate (300a) and / or the second substrate (300b) may be composed of one or a combination of aluminum (Al), zinc (Zn), copper (Cu), nickel (Ni), or cobalt (Co). If the first substrate (300a) and / or the second substrate (300b) are made of a conductive material, an insulating layer may be disposed between the substrate (300a, 300b) and the electrode (200a, 200b) so as not to be electrically connected to the electrode (200a, 200b).

[0073] According to one embodiment, a first substrate (300a) and a second substrate (300b) are arranged to face each other, and a plurality of first electrodes (200a) may be arranged on the inner surface of the first substrate (300a), and a plurality of second electrodes (200b) may be arranged on the inner surface of the second substrate (300b). At least a portion of the first electrodes (200a) and the second electrodes (200b) may be arranged to face each other and may be formed of a conductive material (e.g., a metal material) through which current can travel. For example, the first electrode (200a) and / or the second electrode (200b) may be one or a combination of a plurality of aluminum (Al), zinc (Zn), copper (Cu), nickel (Ni), cobalt (Co), nickel (Ni), gold (Au), silver (Ag), copper (Cu), and titanium (Ti). The first electrode (200a) and the second electrode (200b) may be formed of the same material or different material.

[0074] According to one embodiment, the first electrode (200a) and / or the second electrode (200b) may form a pattern of a specified shape. For example, a plurality of first electrodes (200a) may be arranged at specified intervals on the first substrate (300a). For example, a plurality of second electrodes (200b) may be arranged at specified intervals on the second substrate (300b). The arrangement of the plurality of first electrodes (200a) and the plurality of second electrodes (200b) is not limited to the pattern disclosed in FIG. 1 and may be modified to various patterns that can easily transmit current.

[0075] According to one embodiment, a plurality of thermoelectric legs (110) may each be disposed between a first electrode (200a) and a second electrode (200b). Each thermoelectric leg (110) may have one side connected to the first electrode (200a) and the other side connected to the second electrode (200b).

[0076] According to one embodiment, a plurality of thermoelectric legs (110) may include a plurality of P-type thermoelectric legs (110a) and a plurality of N-type thermoelectric legs (110b). The P-type thermoelectric legs (110a) and N-type thermoelectric legs (110b) may be arranged alternately in one direction. For example, the plurality of thermoelectric legs (110) may be arranged in an arrangement such as M rows x N columns (M, N are natural numbers) on electrodes (200a, 200b) or substrates (300a, 300b). For example, one row (or column) of the plurality of thermoelectric legs (110) may be arranged in the order of P-type thermoelectric leg (110a), N-type thermoelectric leg (110b), P-type thermoelectric leg (110a), and N-type thermoelectric leg (110b).

[0077] According to one embodiment, adjacent P-type thermoelectric legs (110a) in one direction may have their upper and lower surfaces electrically connected in series with the first electrode (200a) and the second electrode (200b). According to one embodiment, adjacent N-type thermoelectric legs (110b) in one direction may have their upper and lower surfaces electrically connected in series with the first electrode (200a) and the second electrode (200b).

[0078] According to one embodiment, a thermoelectric leg (110) (e.g., P-type thermoelectric legs (110a) and N-type thermoelectric legs (110b)) may include a diffusion barrier layer (130). The diffusion barrier layer (130) may be disposed on the upper and / or lower side of the thermoelectric leg (110). The diffusion barrier layers (130) disposed on different sides may be composed of different materials. The diffusion barrier layer (130) may be formed on the thermoelectric leg (110) by a dry deposition process.

[0079] According to one embodiment, the first electrode (200a) and the second electrode (200b) of the thermoelectric element (100) can be electrically connected to a power source. When an external DC voltage is applied, the holes of the P-type thermoelectric leg (110a) and the electrons of the N-type thermoelectric leg (110b) move, thereby causing heat generation and heat absorption to occur at both ends of the thermoelectric leg (110).

[0080] According to one embodiment, at least one of the first electrode (200a) and the second electrode (200b) of the thermoelectric element (100) may be exposed to a heat source. When heat is supplied by an external heat source, electrons and holes move, causing a flow of current in the thermoelectric element to generate electricity.

[0081] According to one embodiment, a heat sink (400a) and a heat absorber (400b) are arranged to face each other and can form one side and the other side of a thermoelectric element (100). The heat sink (400a) may be placed on a first substrate (300a), and the heat absorber (400b) may be placed on a second substrate (300b). Referring to FIG. 1, the heat sink (400a) may form the lower side of the thermoelectric element (100), and the heat absorber (400b) may form the upper side of the thermoelectric element (100). The heat absorber (400b) may be placed on the cold side of the thermoelectric element (100), and the heat sink (400a) may be placed on the hot side, so that they each serve to absorb and release heat.

[0082] According to one embodiment, the heat sink (400a) is a part of the thermoelectric element (100) that emits heat, and heat can be released to the outside by the heat sink (400a). The heat sink (400a) can be positioned on the side with a high temperature to release heat to the outside. By lowering the temperature of the thermoelectric element (100) and preventing overheating, the heat sink (400a) can provide efficient thermoelectric conversion of the thermoelectric element (100) and maintain thermal performance.

[0083] According to one embodiment, the heat absorption plate (400b) is a part where the thermoelectric element (100) absorbs heat, and heat can be absorbed from the outside by the heat absorption plate (400b). The heat absorption plate (400b) can absorb heat by being located on the side with a low temperature. This allows the thermoelectric element (100) to perform the process of absorbing heat and converting it into electrical energy. The heat absorption plate (400b) can rapidly absorb heat and transfer it into the thermoelectric element (100).

[0084] Below, the formation process and structure of the N-type thermoelectric element (100a) will be described in detail.

[0085] FIG. 2 is a schematic diagram showing the process of forming an N-type thermoelectric element according to one embodiment of the present disclosure.

[0086] FIGS. 3a to 3c are drawings showing an apparatus for a secondary crushing process during the formation process of an N-type thermoelectric element according to one embodiment of the present disclosure.

[0087] FIG. 4 is a flowchart showing the process of forming an N-type thermoelectric element according to one embodiment of the present disclosure.

[0088] FIG. 5 is a drawing showing an alloy piece after primary crushing during the formation process of an N-type thermoelectric element according to one embodiment of the present disclosure.

[0089] FIG. 6 is a diagram showing alloy powder after secondary grinding during the formation process of an N-type thermoelectric element according to one embodiment of the present disclosure.

[0090] According to one embodiment, a thermoelectric element (e.g., the thermoelectric element (100) of FIG. 1) includes a thermoelectric leg (110) (e.g., a Peltier leg), and the thermoelectric leg (110) can be formed through a plurality of processes. Hereinafter, the process of forming the thermoelectric leg (110) is an example of an N-type thermoelectric element formation process.

[0091] The configuration of the thermoelectric leg (110) of FIGS. 2 to 6 may be partially or entirely identical to the configuration of the thermoelectric leg (110) of FIG. 1.

[0092] The embodiments of FIGS. 2 to 6 can be optionally combined with the embodiments of FIGS. 1 and FIGS. 7 to 11.

[0093] According to one embodiment, the thermoelectric leg (110) may be a thermoelectric semiconductor, a thermoelectric material in which a temperature difference occurs between two ends when electricity is applied, or a thermoelectric material in which electricity is generated by the temperature difference between two ends. The thermoelectric leg (110) may be designed in a cylindrical shape or a rectangular column shape. The thermoelectric leg (110) may be an N-type thermoelectric leg (110b) of FIG. 1.

[0094] According to one embodiment, the material of the thermoelectric leg (110) (or the materials before being formed into the thermoelectric leg (110) (e.g., alloy material (510), alloy piece (520), alloy powder (530))) may include at least one element selected from the group consisting of transition metals, rare earth elements, group 13 elements, group 14 elements, group 15 elements, or group 16 elements. For example, the above rare earth elements include elements such as Y, Ce, and La, and the above transition metal may be one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, Ag, or Re, examples of the above group 13 elements may be one of B, Al, Ga, or In, examples of the above group 14 elements may be one of C, Si, Ge, Sn, or Pb, examples of the above group 15 elements may be one of P, As, Sb, or Bi, and examples of the above group 16 elements may be one of S, Se, or Te.

[0095] According to one embodiment, the thermoelectric leg (110) (or materials prior to being formed into the thermoelectric leg (110) (e.g., alloy material (510), alloy piece (520), alloy powder (530))) may be composed of a composition including at least two of bismuth (Bi), tellurium (Te), selenium (Se), cobalt (Co), antimony (Sb), indium (In), or cerium (Ce). For example, the thermoelectric leg (110) may be at least one of a Bi-Te system, a Co-Sb system, a Pb-Te system, a Ge-Tb system, a Si-Ge system, a Sb-Te system, a Sm-Co system, a transition metal silicide system, a skuttrudite system, a silicide system, or a Half-Whistler system. For example, the thermoelectric leg (110) may include a (Bi,Sb)2(Te,Se)3 thermoelectric semiconductor in which Sb and Se are used as dopants as a Bi-Te thermoelectric semiconductor. For example, the thermoelectric leg (110) may include a CoSb3 thermoelectric semiconductor as a Co-Sb thermoelectric semiconductor. For example, the thermoelectric leg (110) may include AgSbTe2 or CuSbTe2 as an Sb-Te thermoelectric semiconductor. For example, the thermoelectric leg (110) may include PbTe or (PbTe)mAgSbTe2 as a Pb-Te thermoelectric semiconductor. Hereinafter, the thermoelectric leg (110) is described on the premise that it is composed of a Bi-Te-based (e.g., Bi2-Te3-based) thermoelectric material.

[0096] The process of forming the thermoelectric leg (110) is described in detail below. Before forming the thermoelectric leg (110), the materials can be named alloy material (510), alloy piece (520), and alloy powder (530) depending on their size.

[0097] According to process 100, a process for preparing an alloy material (510) can be performed. According to one embodiment, the alloy material (510) may be a peltier material (or peltier element) including a Bi-Te system (e.g., Bi2-Te3 system). For example, the peltier material is a key component used in a thermoelectric module utilizing the peltier effect, and the peltier effect is a phenomenon in which heat is absorbed or released when current flows between two types of semiconductors (e.g., P-type and N-type semiconductors), thereby creating a temperature difference.

[0098] According to one embodiment, the alloy material (510) may be named an alloy ingot or an alloy lump. The alloy material (510) may have a lump shape of a specified size as shown in FIG. 2 before main processing is performed. For example, the alloy material (510) may be manufactured into a cylindrical shape before crushing processing is performed.

[0099] According to one embodiment, the alloy material (510) may be the same or similar to the material of the thermoelectric leg (110) described above. The alloy material (510) may be a material based on bismuth (Bi) and tellurium (Te) with added selenium (Se). The selenium (Se) may be added in small amounts to a Bi-Te series thermoelectric alloy. The selenium (Se) may be contained in an amount of 0.1 to 0.5 mol.% relative to the total mol.% of the alloy material (510). The selenium (Se) may improve the electrical conductivity and / or thermoelectric performance of the Bi-Te series thermoelectric alloy.

[0100] According to one embodiment, the alloy material (510) may be manufactured in a shape similar to a cylinder as a crushing ingot or lump to facilitate a primary crushing process. According to one embodiment, the alloy material (510) may be processed through a melting and casting process. For example, the processed alloy material (510) may be formed to have a diameter (Φ) of approximately 25 mm to 40 mm and a length of approximately 50 mm to 300 mm. For example, the alloy material (510) may have a length of approximately 300 mm or less. For example, the alloy material (510) may have a weight of approximately 200 g or less. For example, the alloy material (510) may have a weight of approximately 50 g to 200 g. The size and weight of the alloy material (510) disclosed above are examples formed to be easily inserted into the primary crushing equipment (610), but are not limited thereto, and can be designed to be changed to various sizes considering the primary crushing process.

[0101] According to process 200, a primary grinding (coarse grinding or rough grinding) process can be performed on the prepared Bi-Te alloy material (510). Process 200 is an initial grinding process among multiple grindings for forming a thermoelectric leg (110), and through the primary grinding process, the alloy material (510) can be formed into an alloy piece (520) having a first length (L1).

[0102] According to one embodiment, the primary crushing process proceeds by crushing the alloy material (510) through a primary crushing device (610), and the primary crushing device (610) may be named a jaw crusher. The primary crushing device (610) may include a plurality of crushing plates (611) (jaws). The primary crushing device (610) includes a stationary jaw and a movable jaw, and the two crushing plates (611) may be closely engaged to compress the alloy material (510). For example, the alloy material (510) may be fed into the gap between the two crushing plates (611) with the gap set to approximately 1 mm to 5 mm. The crushing plates (611) may be made of cemented carbide. When the alloy material (510) enters the inlet (612) of the primary crushing equipment (610), the fixed crushing plate and the moving crushing plate move up / down or forward / backward to compress and crush the alloy material (510) from one end. The alloy material (510) moving according to the up / down or forward / backward movement can be crushed into pieces of gradually smaller size. The crushed material (e.g., alloy pieces (520)) is discharged through the outlet (613) and can be separated into pieces of uniform size.

[0103] According to one embodiment, the alloy pieces (520) are pieces that have been crushed to a size smaller than the alloy material (510) to facilitate a secondary crushing process, and can be prepared into pieces of generally uniform size through a primary crushing equipment (610). Referring to FIG. 5, the alloy pieces after primary crushing are shown. For example, each of the alloy pieces (520) may have a length of approximately 30 mm or less on average (e.g., a first length (L1)). For example, each of the alloy pieces (520) may have an irregular shape but may have a length of approximately 10 mm to 30 mm, a width of approximately 10 mm to 30 mm, and a thickness of approximately 10 mm to 30 mm on average. The size of the alloy piece (520) disclosed above is an example formed to be easily inserted into the secondary crushing equipment (620), but is not limited thereto and can be designed to be changed to various sizes considering the secondary crushing process.

[0104] According to process 300, a secondary grinding (medium grinding) process can be performed on the primary grinding (coarse grinding or rough grinding) of the alloy piece (520). Process 300 is the final grinding process among multiple grindings for forming the thermoelectric leg (110), and through the secondary grinding process, the alloy piece (520) can be ground into an alloy powder (530) having a second length (L2). The alloy powder (530) that has undergone the secondary grinding process may be in a plate shape or a flake shape.

[0105] According to one embodiment, the secondary crushing process proceeds with the crushing of an alloy piece (520) inserted into a secondary crushing device (620), and the secondary crushing device (620) may be named a disk mill. The secondary crushing device (620) may include a plurality of disks (621).

[0106] Referring to FIGS. 3a, 3b, and 3c, the secondary crushing equipment (620) may include two rotatable circular discs (621), an inlet (622), an outlet (623), a motor, and / or an adjusting mechanism. In the secondary crushing process, two parallel discs (621) are positioned facing each other, with the first disc (621a) of the discs (621) being stationary and the second disc (621b) providing rotational motion, and an alloy piece (520) may be fed between the discs (621). The alloy piece (520) may be crushed by friction and impact between the rotating second disc (621b) and the stationary first disc (621a). As the surfaces of the discs (621) typically include a sawtooth shape or a rough surface, the alloy piece (520) may be efficiently crushed while in contact between the discs (621). The discs (621) are made of steel or alloy and can be made of durable and wear-resistant materials.

[0107] According to one embodiment, in the secondary grinding process, the spacing between the discs (621) for grinding the alloy pieces (520) can be set to 0.1 mm to 10 mm. The set spacing can be adjusted by an operator to obtain an improved thermoelectric leg (110), and the adjustment can be made through the adjusting mechanism. According to one embodiment, in the secondary grinding process, the rotational speed of the second disc (621) can be set to approximately 440 RPM.

[0108] According to one embodiment, in a secondary crushing process, an alloy piece (520) fed into an inlet (622) is compressed and crushed while passing between discs (621) to be transformed (e.g., crushed) into a plate-shaped alloy powder (530), and the transformed plate-shaped alloy powder (530) can be discharged through an outlet (623). The material crushed through the secondary crushing equipment (620) (e.g., plate-shaped alloy powder (530)) can be crushed into pieces of uniform size and separated through the outlet (623). The alloy piece (520) fed into the inlet (622) can be approximately 50g to 200g at a time.

[0109] According to one embodiment, the alloy powder (530) is a powder that is ground to a size smaller than the alloy piece (520) so that it can be easily formed into a sintered material for the thermoelectric leg (110), and can be prepared into plate-shaped powders of generally uniform size through a secondary grinding device (620). Referring to FIG. 6, the secondary ground alloy powders (530) are shown. For example, each of the plate-shaped alloy powders (530) may have a length of approximately 200 μm or less on average (e.g., a second length (L2)). For example, each of the plate-shaped alloy powders (530) may have an irregular shape but may have a length of approximately 100 μm to 200 μm, a width of approximately 100 μm to 150 μm, and a thickness of 5 μm to 20 μm on average. The size of the alloy powder (530) disclosed above is an example for easily forming a thermoelectric leg (110) through a sintering process, but is not limited thereto, and can be designed and changed to various sizes considering the efficiency of the thermoelectric leg (110).

[0110] According to one embodiment, with reference to FIG. 6, each of the alloy powders (530) may comprise a plate-shaped particle (531) and a plurality of fine particles (532) that are at least partially inserted on the plate-shaped particle (531). The alloy powders (530) are formed by passing through the discs (621) of a secondary grinding equipment (620), and the alloy powders (530) formed thereby may be provided in an overall plate shape to be advantageous for orientation and electrical conductivity. For example, the discs (621) of the secondary grinding equipment (620) are equipment capable of applying shear stress in a horizontal direction, and when an alloy piece (520) having a layered structure passes between the discs (621) and is ground, a shear force is applied in the direction of the interlayer bonding of the layered structure with weak bonding (e.g., c-axis bonding in FIG. 7), thereby causing interlayer slip and / or separation, so that a thin plate-shaped structure can be easily formed.

[0111] According to process 400, a classification process of secondary ground (medium grinding) alloy powders (530) can be performed. Process 400 is a process of classifying secondary ground alloy powders (530) by size, and among the classified alloy powders (530), only alloy powders (530) that are advantageous for the thermoelectric leg (110) can be used by comparing performance (e.g., electrical conductivity, orientation) according to size.

[0112] According to one embodiment, the classification process (e.g., process 400) is carried out by performing classification multiple times (e.g., three times) to classify the secondary crushed alloy powders (530) by size, and the classification may utilize various classification methods such as sieving or centrifugal classification. Sieving is described below.

[0113] According to one embodiment, the classification process is carried out in a total of three stages. In the first classification stage, a sieve is used that allows only alloy powders (530) with a length of 180 μm or less to pass through. In the second classification stage, a sieve is used that allows only alloy powders (530) with a length of 90 μm or less to pass through. In the third classification stage, a sieve is used that allows only alloy powders (530) with a length of 53 μm or less to pass through. Through the classification process, the alloy powders (530) are classified into alloy powders (530) with a length of approximately 90 μm to 180 μm, alloy powders (530) with a length of approximately 53 μm to 90 μm, and alloy powders (530) with a length of approximately 53 μm or less. Through an experiment (e.g., FIG. 9), alloy powders (530) with a power factor (PF) of approximately 90 μm to 180 μm or more can be used in the next process (e.g., forming a thermoelectric leg (110)).

[0114] According to process 500, a press forming process for forming a sintered material can be performed. The sintering process is a manufacturing method that combines raw materials in an alloy state by applying heat at a high temperature to form a solid form, and may be a process for sintering the alloy powders (530) of 90㎛ to 180㎛ to form a thermoelectric leg (110).

[0115] According to one embodiment, the press forming process can be performed by preparing alloy powder (530), filling the alloy powder (530) into the die, and compressing it, and then extracting the formed product after the forming is complete. The alloy powder (530) for the preparation may have a size of approximately 90 μm to 180 μm. When filling the alloy powder (530) into the die, it must be ensured that no foreign substances or air bubbles enter the interior, and when compressing, high pressure (e.g., 100 MPa or more) is used, and through this process, the alloy powder (530) may be finely aggregated and its density may increase.

[0116] According to one embodiment, the alloy powder (530) compressed by the press forming process has low mechanical strength and may be brittle, so the high-temperature treatment process can proceed immediately.

[0117] According to process 600, a hot extrusion process can be performed to form a sintered material. Through the hot extrusion process, alloy powders (530) that do not have sufficient mechanical strength after press forming can be strongly bonded (sintered). The sintered alloy is smaller in size than the alloy powders (530), and the sintered powders may be bonded with orientation.

[0118] According to one embodiment, the hot extrusion process may prepare a material to be extruded (e.g., in the form of a billet or preform) and heat it to a specified temperature. The heating is intended to facilitate the deformation of the material, and the temperature may vary depending on the type of material, but may be approximately 300°C to 500°C. After heating, the material is inserted into an extrusion machine and pushed through a die by applying strong pressure, and the material may have a continuous shape with a constant diameter (or width). Subsequently, the extruded material may form a thermoelectric leg (110) through cooling and post-processing. Cooling may be selectively performed between natural cooling or forced cooling. Post-processing may include cutting, surface treatment, and machining. A sintered body (540) (sintered alloy, sintered powders, or crystal grains) and / or a thermoelectric leg (110) can be formed by cutting and surface treating the material multiple times to a size to be used in a thermoelectric element (100).

[0119] According to one embodiment, the thermoelectric leg (110) that has undergone a sintering process and post-treatment may have multiple layers, such as diffusion barrier layers, placed on both sides of the thermoelectric leg (110) to improve performance.

[0120] FIG. 7 is a diagram showing a structure in which plate-shaped alloy powder is formed in a process of forming an N-type thermoelectric element according to one embodiment of the present disclosure.

[0121] FIG. 8a is an enlarged view of a portion of a sintered body that has undergone a sintering process after grinding, according to one embodiment of the present disclosure.

[0122] FIG. 8b is a drawing showing the shape and thermal conductivity of alloy powder crushed by a crushing device according to one embodiment of the present disclosure.

[0123] According to one embodiment, a thermoelectric element (e.g., the thermoelectric element (100) of FIG. 1) includes a thermoelectric leg (110) (e.g., a Peltier leg) (e.g., the thermoelectric leg (110) of FIG. 1), and the thermoelectric leg (110) can be formed through a plurality of processes. Hereinafter, the process of forming the thermoelectric leg (110) is an example of an N-type thermoelectric element formation process.

[0124] The configuration of the thermoelectric leg (110) in FIGS. 7 to 8b may be partially or entirely identical to the configuration of the thermoelectric leg (110) in FIG. 1.

[0125] The embodiments of FIGS. 7 to 8b can be optionally combined with the embodiments of FIGS. 1 to 6 and FIGS. 9 to 11.

[0126] According to one embodiment, the thermoelectric leg (110) forming process may include a primary grinding (coarse grinding or rough grinding) process of a Bi-Te alloy material (510) (e.g., process 200 of FIG. 4), a secondary grinding (medium grinding) process of the primary grinding (coarse grinding or rough grinding) alloy piece (e.g., process 300 of FIG. 4), and a sintering process (e.g., process 500, process 600 of FIG. 4).

[0127] According to one embodiment, a grinding process (e.g., a first grinding process, a second grinding process) can improve the thermoelectric performance (e.g., electrical conductivity, orientation) of the thermoelectric leg (110) by utilizing the unique characteristics of the HCP crystal structure of the Bi-Te system. Generally, Bi-Te thermoelectric materials with a layered structure have weak interlayer bonding or are bonded only by van der Waals forces, so the bonding can easily break when subjected to force in the vertical direction (e.g., c-axis). For example, in Bi-Te thermoelectric materials, the c-axis direction has low mechanical strength and is weak, so it is more likely to break easily than the a-axis or b-axis direction; therefore, when designing the thermoelectric material, it is necessary to control the orientation by considering structural stability (e.g., mechanical weakness in the c-axis direction).

[0128] According to one embodiment, when alloy pieces (520) are crushed into plate-shaped alloy powders (530) using equipment capable of applying shear stress to a Bi-Te-based thermoelectric material having a layered structure (e.g., secondary crushing equipment (620) of FIGS. 2 and 3), the thermoelectric material can be manufactured with structural stability and improved orientation. For example, alloy pieces (520) fed to pass between the rotating discs (621) of the secondary crushing equipment (620) can be crushed into thin plate-shaped alloy powders (530) as interlayer separation occurs easily due to weak c-axis bonding due to the characteristics of the layered structure. The plate-shaped alloy powders (530) generated through the shear stress of the secondary crushing equipment (620) exist in a state where only strong bonding in the a-axis and b-axis directions is maintained, thereby providing a structure that facilitates stacking with a specific directionality (e.g., orientation).

[0129] The first figure of FIG. 7 shows a structure in which the bonding in the c-axis direction is weak according to the HCP crystal structure, and through multiple grinding processes, it can be seen that alloy powders (530) in which only strong bonding in the a-axis and b-axis directions is maintained are schematically shown as in the second figure of FIG. 7. When the alloy powders (530) undergo a sintering process (pressing and hot extrusion), they can form a sintered material (540) (e.g., thermoelectric leg (110)) with excellent orientation.

[0130] According to one embodiment, the performance of a thermoelectric element can be significantly influenced by the orientation of the sintered body (540) (sintered alloy). For example, in a Bi-Te-based thermoelectric material, the (0001) plane (e.g., a basal plane or a plane perpendicular to the c-axis) is the most important plane for thermoelectric performance and can affect mechanical, electrical, and thermoelectric properties such as electrical conductivity, thermal conductivity, and / or the Seebeck coefficient. That is, when the crystal structure is aligned in a certain direction (e.g., to have orientation), the path for electron flow becomes clearer, and electrical conductivity can be improved. For example, an oriented crystal structure can facilitate electron flow by reducing defects or irregular paths that hinder electron movement.

[0131] Referring to FIG. 8a, it can be seen that the alloy powders (530) form a sintered material (540) (e.g., thermoelectric leg (110)) through a sintering process (pressing and hot extrusion). It can be seen that the sintered material (540) in FIG. 8a has oriented crystal grains (e.g., sintered powders). For example, the sintered material (540) is composed of plate-shaped alloy powders (530) sintered through multiple grinding processes in which only strong bonds in the a-axis and b-axis directions are maintained. The crystal grains of the sintered material (540) form a structure with high orientation, and accordingly, electrical conductivity and thermal conductivity can be improved.

[0132] Referring to the enlarged view of FIG. 7, a portion of the plate-shaped alloy powder (530) is enlarged, and each of the alloy powders (530) may include a plate-shaped particle (531) and a plurality of fine particles (532) that are at least partially inserted on the plate-shaped particle (531). The plate-shaped particle (531) is formed by passing through the discs (621) of the secondary grinding equipment (620), thereby improving the orientation and electrical conductivity of the thermoelectric leg (110) formed thereby. Fine particles (532) that are ground to be smaller (e.g. thin and fine) than the plate-shaped particle (531) may be placed on the surface or inside of the plate-shaped particle (531). The fine particles (532) are formed by passing through the discs (621) of the secondary grinding equipment (620), thereby reducing the thermal conductivity of the thermoelectric leg (110) formed thereby. The microparticles (532) may be positioned irregularly inserted (or embedded) into the surface or inside of the plate-shaped particles (531). For example, each of the microparticles (532) may be positioned such that some are located inside the plate-shaped particles (531) and others are exposed outside the plate-shaped particles (531). The microparticles (532) may be positioned in numbers ranging from tens to thousands on the surface or inside of the plate-shaped particles (531). For example, the plate-shaped particles (531) may have a length of approximately 200 μm or less on average. For example, each of the microparticles (532) may have a length of approximately 500 nm to 1 μm or less on average.

[0133] Referring to FIG. 8b, the thermal conductivity of alloy powders for grinding equipment is shown, and the types of grinding equipment may be ball mills, hand grinding, and disc mills (e.g., secondary grinding equipment (620)). It can be seen that powders produced by ball mills exhibit various shapes with irregular sizes and have a thermal conductivity of approximately 1.785 W / Mk on average. Powders produced by hand grinding have a clean surface and plate-like particles, but it can be seen that the increase in PF is limited due to high thermal conductivity (approximately 1.708 W / Mk on average). In contrast, alloy powders (530) produced (e.g., ground) by disc mills (e.g., secondary grinding equipment (620)) according to one embodiment of the present disclosure exhibit plate-like particles (531) similar to those produced by hand grinding, and it can be seen that fine particles (532) are relatively abundantly distributed on the surface. Due to these effects, the thermal conductivity can be reduced (approximately 1.64 W / Mk on average) to improve the PF. Generally, there is a trade-off relationship where the more fine particles there are, the lower the electrical conductivity and the higher the Seebeck coefficient. The structure of the alloy powder (530) produced through the disc mill can limit (e.g., prevent or reduce) the increase in thermal conductivity while maintaining high electrical conductivity, so it can be provided as a material for a thermoelectric element that provides an improved thermoelectric effect.

[0134] FIG. 9 is a diagram showing the power factor (PF) according to the size of the alloy powder according to one embodiment of the present disclosure.

[0135] According to one embodiment, a thermoelectric element (e.g., the thermoelectric element (100) of FIG. 1) includes a thermoelectric leg (110) (e.g., a Peltier leg) (e.g., the thermoelectric leg (110) of FIG. 1), and the thermoelectric leg (110) can be formed through a plurality of processes. Hereinafter, the process of forming the thermoelectric leg (110) is an example of an N-type thermoelectric element formation process.

[0136] The configuration of the thermoelectric leg (110) of FIG. 9 may be partially or entirely identical to the configuration of the thermoelectric leg (110) of FIG. 1.

[0137] The embodiments of FIG. 9 can be optionally combined with the embodiments of FIG. 1 to 8b and FIG. 10 to 11.

[0138] According to one embodiment, the thermoelectric leg (110) forming process may include a primary grinding (coarse grinding or rough grinding) process of a Bi-Te alloy material (510) (e.g., process 200 of FIG. 4), a secondary grinding (medium grinding) process of the primary grinding (coarse grinding or rough grinding) alloy piece (e.g., process 300 of FIG. 4), a classification process of the secondary grinding (medium grinding) alloy powder (e.g., process 400 of FIG. 4), and a sintering process (e.g., process 500, process 600 of FIG. 4).

[0139] According to one embodiment, the classification process (e.g., process 400 of FIG. 4) is a process for classifying secondary crushed alloy powders (530) by size, and the classified alloy powders may be a preliminary process for using only alloy powders (530) that are advantageous for the thermoelectric leg (110) by comparing performance (e.g., electrical conductivity, orientation) according to size. The performance can be verified through a power factor (PF) (e.g., Seebeck coefficient).

[0140] According to one embodiment, the classification process can classify alloy powder (530) of approximately 90㎛ to 180㎛, alloy powder (530) of approximately 53㎛ to 90㎛, and alloy powder (530) of approximately 53㎛ or less, and FIG. 9 can be used to check the power factor (PF) when a sintered body (540) is formed from the classified alloy powders (530).

[0141] Referring to Fig. 9, it can be seen that a sintered body (sintered alloy) using alloy powder of approximately 53 μm or less has a PF value of approximately 2.5 to 3.0 or less. It can be seen that a sintered body (sintered alloy) using alloy powder of approximately 53 μm to 90 μm has a PF value of approximately 2.9 to 3.4 or less. It can be seen that a sintered body (sintered alloy) using alloy powder of approximately 90 μm to 180 μm has a PF value of 3.7 or more (e.g., approximately 3.9 on average).

[0142] According to one embodiment, the power factor (PF) is defined by the relationship between the Seebeck coefficient (S) and the electrical conductivity (σ).

[0143] [formula]

[0144]

[0145] In the above formula, S is the Seebeck coefficient, which represents the potential difference due to thermal and electrical driving, and σ is the electrical conductivity, which indicates how well a material conducts electricity.

[0146] The above power factor (PF) is an indicator for evaluating the electrical performance of a thermoelectric device and can play an important role in maximizing the thermoelectric effect. For example, a higher PF may mean that the thermoelectric device has a higher efficiency in converting heat into electrical energy. For example, PF represents the thermoelectric conversion efficiency of a thermoelectric device, and it can be confirmed through the above formula that materials with superior electrical performance have a higher PF.

[0147] According to one embodiment of the present disclosure, a thermoelectric element can be provided as a material in the case of a sintered body (sintered alloy) using alloy powder of approximately 90 μm to 180 μm, which provides a high PF and thereby provides an improved thermoelectric effect.

[0148] Figure 10a is a diagram showing the shape of the powder and EBSD (electron backscatter diffraction) by a general mechanical alloying method.

[0149] FIG. 10b is a diagram showing the shape of a powder and electron backscatter diffraction (EBSD) by multiple grinding steps according to one embodiment of the present disclosure.

[0150] According to one embodiment, a thermoelectric element (e.g., the thermoelectric element (100) of FIG. 1) includes a thermoelectric leg (110) (e.g., a Peltier leg) (e.g., the thermoelectric leg (110) of FIG. 1), and the thermoelectric leg (110) can be formed through a plurality of processes. Hereinafter, the process of forming the thermoelectric leg (110) is an example of an N-type thermoelectric element formation process.

[0151] The composition of the alloy powder (530) and sintered body (540) of the thermoelectric leg (110) in FIG. 10b may be partially or entirely the same as the composition of the alloy powder (530) and sintered body (540) of the thermoelectric leg (110) in FIG. 1 to 9.

[0152] The embodiments of FIG. 10b can be optionally combined with the embodiments of FIG. 1 to 9 and the embodiment of FIG. 11.

[0153] The electron backscatter diffraction (EBSD) of FIGS. 10a and 10b can also be referred to as electron backscatter diffraction patterns or electron backscatter diffraction analysis, and is generally used as a technique to analyze the crystal structure and microstructure of materials using a scanning electron microscope (SEM). For example, electron backscatter diffraction (EBSD) is useful for investigating and visualizing the microstructure of a material, such as grain orientation and grain size, at high resolution, and can provide important information for analyzing the shape of one side of a material, such as crystal planes, crystal orientations, and deformation modes.

[0154] Referring to FIG. 10a, the powder shape produced by a general mechanical alloying method can be observed. The powder shape of FIG. 10a is a collection of powders with irregular sizes, and the sintered body of the powders has uneven grain sizes, and when the sintered body (sintered alloy) is formed, it may have a structure with weak orientation.

[0155] Referring to FIG. 10b, the shape of plate-shaped alloy powder (530) evenly distributed by a multiple crushing process (e.g., secondary crushing equipment) can be observed. The plate-shaped powder shape of FIG. 10b is a collection of regular plate-shaped powders in which the c-axis is crushed and the a-axis and b-axis are strongly bonded, and the sintered body (540) (sintered alloy) of the powders can have a structure in which the grain size is uniform and the orientation is strong.

[0156] Referring to the EBSD of FIGS. 10a and 10b, the orientation of the grains of the sintered body (540) (sintered alloy) can be confirmed through the (0001) plane (e.g., 00015 of the pole figure in FIGS. 10a and 10b) and the (1120) plane through the pole figure. The pole figure is a tool for visually representing the crystal direction or grain direction and can show the collective distribution related to the orientation of a specific crystal plane. The (0001) plane represents a base plane perpendicular to the c-axis direction, and the more the central colored band (e.g., red band) is highlighted, the better the orientation of the grains. The (1120) plane is related to the a-axis direction and can be used for grain arrangement or microstructure analysis.

[0157] In the (0001) plane (e.g., 00015) of the pole figure referenced in the EBSD of FIG. 10a, the central color band (e.g., red band) appears less, whereas in the (0001) plane (e.g., 00015) of the pole figure referenced in the EBSD of FIG. 10b, the central color band (e.g., red band) appears accurately and thickly along the center. Accordingly, it can be confirmed that the orientation of the sintered body (540) manufactured in the plate-shaped powder form of the present disclosure is excellent.

[0158] In the enlarged view of the sintered body with reference to the EBSD of FIG. 10a, crystal grains of various sizes are arranged and have an irregular shape with inconsistent orientations, whereas in the enlarged view of the sintered body with reference to the EBSD of FIG. 10b, crystal grains of a uniform size are arranged and have a regular shape arranged parallel to one direction (e.g., longitudinal direction). Accordingly, it can be confirmed that the orientation of the plate-shaped powder sintered body of the present disclosure is excellent.

[0159] According to one embodiment, it can be confirmed that the Power Factor (PF) value of the sintered body of FIG. 10a is approximately 3.6, and the Power Factor (PF) value of the sintered body of FIG. 10b is 3.7 or higher (e.g., approximately 3.9 on average). Accordingly, it can be confirmed that the electrical conductivity of the plate-shaped powder sintered body of the present disclosure is excellent.

[0160] Hereinafter, a general configuration of a refrigerator in which the thermoelectric element (100) (e.g., thermoelectric leg (110)) of the present disclosure is used is described. However, the thermoelectric element (100) of the present disclosure can be easily modified and applied to various home appliances in which thermoelectric elements are utilized, such as air purifiers, robot vacuum cleaners, cooking appliances, or washing machines, in addition to refrigerators.

[0161] FIG. 11 is a perspective view of a refrigerator according to one embodiment of the present disclosure.

[0162] Referring to FIG. 11, the refrigerator (1) may include a main body (10), a storage room (20), a door (30), and / or a cold air supply device.

[0163] According to one embodiment, the storage room (20) may be partitioned inside the main body (10) and formed into multiple spaces. A door (30) may be positioned at the front of the main body (10) to open and close the storage room (20). A cold air supply device may be provided inside the main body (10) to supply cold air to the storage room (20).

[0164] According to one embodiment, the main body (10) may include an inner housing (11) and / or an outer housing (12). The inner housing (11) may be provided to form, for example, the exterior of the storage room (20). The inner housing (11) may be, for example, made of a plastic material and injection molded integrally. The outer housing (12) may be provided to form, for example, at least a part of the exterior of the refrigerator (1). The outer housing (12) may be made of, for example, a metal material with excellent durability and aesthetic appeal. A receiving space may be formed between the inner housing (11) and the outer housing (12). A main body insulation material (not shown) that insulates the storage room (20) may be provided in part of the receiving space.

[0165] According to one embodiment, a cold air supply device can generate cold air by using a cooling circulation cycle that compresses, condenses, expands, and evaporates a refrigerant.

[0166] According to one embodiment, the storage room (20) may be divided into multiple sections by partitions (14). The storage room (20) may be formed by the internal housing (11) of the main body (10) and the partitions (14). Inside the storage room (20), a plurality of shelves (24) or storage containers (25) may be provided to store food or the like. The plurality of shelves (24) and storage containers (25) may be provided, for example, so as to be separable.

[0167] According to one embodiment, the storage room (20) may be divided into a plurality of storage rooms (21, 22, 23) by a partition wall (14). For example, the storage room (20) may include one first storage room (21) located at the top (e.g., upper storage room) and two second storage rooms (22) (e.g., lower storage rooms) and a third storage room (23) (e.g., lower storage room) located at the bottom, as illustrated.

[0168] According to one embodiment, the partition (14) may include a first partition (141) and a second partition (142). The partition (14) may, for example, have a T-shaped cross-section. The first partition (141) may be provided horizontally, for example, to partition the first storage room (21) and the second and third storage rooms (22, 23). The second partition (142) may be provided vertically, for example, to partition the second storage room (22) and the third storage room (23). The second partition (142) may be formed to protrude downward from the first partition (141), for example. The illustrated second partition (142) is formed protruding from the center of the first partition (141), but is not limited thereto, and the size of the second storage room (22) and the third storage room (23) may vary depending on the position of the second partition (142).

[0169] Among the illustrated storage rooms (20), the first storage room (21) can be used as a refrigerator room, and the second and third storage rooms (22, 23) can be used as freezer rooms, but are not limited thereto, and the location and number of each refrigerator room and freezer room can be varied according to the user's needs.

[0170] According to one embodiment, the number, size, or shape of the storage rooms (20) may vary depending on the shape or location of the partition wall (14). The freezer room may be maintained at approximately minus 20 degrees, and the refrigerator room may be maintained at approximately plus 3 degrees. The storage rooms (20) may be insulated, for example, by the partition wall (14).

[0171] According to one embodiment, the storage room (20) may be divided into left and right sections by a single vertical partition. Here, the vertical partition may be formed such that one end contacts the upper part of the inner housing (11) and the other end contacts the lower part of the inner housing (11). Depending on the position of the vertical partition, the size of the storage room (20) divided into left and right sections may vary. For example, the vertical partition may be provided in the center so that the storage room (20) divided into left and right sections is provided in a mirror-symmetric manner. According to one embodiment, there may be multiple vertical partitions. If there are multiple vertical partitions, three or more storage rooms (20) may be provided in the left and right directions.

[0172] According to one embodiment, the storage room (20) may be divided only into upper and lower sections by a single horizontal partition. That is, the storage room (20) may be divided into two sections, an upper storage room and a lower storage room. Here, the horizontal partition may be formed such that one end contacts the left side of the inner housing (11) and the other end contacts the right side of the inner housing (11). Depending on the position of the horizontal partition, the size of the upper and lower divided storage room (20) may vary. According to one embodiment, there may be multiple horizontal partitions. If there are multiple horizontal partitions, three or more storage rooms (20) may be provided in the upper and lower directions. In addition to the above-described embodiment, multiple storage rooms (20) of various types may be configured depending on the shape and number of the partitions (14).

[0173] According to one embodiment, the door (30) may include a first door (31) (e.g., upper door) or a second door (32) (e.g., lower door) as illustrated. The door (30) may be provided to open and close, for example, an opening (10a) of the main body (10). The first door (31) may be provided as a pair (e.g., double door) to open and close the first storage room (21), for example. The second door (32) may be provided as a pair (e.g., double door) to open and close the second storage room (22) or the third storage room (23), for example. In addition, the number and shape of the door (30) may vary in correspondence with the number and shape of the storage room (20), and the door (30) may be configured to rotate around the hinge (16) as well as to slide.

[0174] According to one embodiment, a rotating bar (316) may be provided on one of the pair of first doors (31). The rotating bar (316) may be positioned, for example, on the side opposite to the side forming the axis of rotation in one of the pair of first doors (31). The rotating bar (316) may be provided, for example, so that the axis of rotation is fixed to the side of one of the pair of first doors (31) and can rotate around the axis of rotation. The rotating bar (316) may be provided, for example, to be positioned in the center of the front of the main body (10) when one of the pair of first doors (31) is closed. The rotating bar (316) can seal the gap between the pair of first doors (31) when the pair of first doors (31) are closed. The main body (10) may be provided with a rotating bar guide (15) that guides the movement of the rotating bar (316) when one of the pair of first doors (31) is closed.

[0175] According to one embodiment, the door (30) (e.g., first door (31) or second door (32)) may include a door panel (30a) or a door body (30b). The door panel (30a) and the door body (30b) may be joined so as to be detachable.

[0176] According to one embodiment, the door body (30b) may be fixed to the main body (10) at one side by a hinge (16), for example. The door body (30b) may be provided to be rotatable relative to the main body (10). The door panel (30a) may form part of the front exterior of the refrigerator (1), for example. The door panel (30a) may be an important aesthetic element, particularly when the refrigerator (1) is placed indoors. Accordingly, the user may customize the front exterior of the refrigerator (1) as desired by replacing the door panel (30a) with one having a different color or design. According to some embodiments, the door panel (30a) and the door body (30b) may be formed as a single unit.

[0177] For convenience of explanation, only one first door (31) and one second door (32) are described below, and the description of the remaining first door (31) and the remaining second door (32) is omitted. However, the first door (31) and the second door (32) for which the description is omitted may each have a configuration approximately identical to that of the first door (31) and the second door (32) described below, except that they are arranged in a mutual mirror-symmetrical manner. Additionally, the second door (32) may have the same configuration as the first door (31), and a detailed description may be omitted.

[0178] According to one embodiment, the first door (31) may include a first door handle (not shown), a first door shelf (313), a first shelf support (314), or a first gasket (315). The first door (31) may be rotatably coupled to the main body (10), for example, to open and close at least a portion of the first storage room (21). A user may open and close the first door (31) using the first door handle. The first door handle may be formed as a recess on the bottom surface of the first door (31) or as a protrusion on the front surface of the first door (31), but is not limited thereto.

[0179] According to one embodiment, the first door shelf (313) may be provided to store food, for example. On both the left and right sides of the first door shelf (313), a first shelf support (314) may be provided to support the first door shelf (313). The first shelf support (314) may be formed to extend vertically from the first door (31), for example. That is, the first shelf support (314) may be provided to protrude rearward from the back surface of the first door (31) and extend in the vertical direction. The first shelf support (314) may be provided detachably to the first door (31) as a separate component, for example, or may be formed integrally. The first shelf support (314) may be formed to protrude rearward from the rear surface of the door body (30b), for example.

[0180] According to one embodiment, the first gasket (315) may be provided to wrap around the back edge of the first door (31), for example. Specifically, the first gasket (315) may be provided to wrap around the edge of the door body (30b). The first gasket (315) may be provided to seal the gap with the main body (10) when the first door (31) is closed.

[0181] According to one embodiment, the second door (32) may include a second door handle (321) or a second gasket (322). The second door (32) may be rotatably coupled to the main body (10), for example, to open and close the second storage room (22) or the third storage room (23). A user may open and close the second door (32) using the second door handle (321). The second door handle (321) may be formed as a recess on the upper surface of the second door (32) or as a protrusion on the front surface of the second door (32), but is not limited thereto.

[0182] According to one embodiment, the second gasket (322) may be provided to wrap around, for example, the back edge of the second door (32). The second gasket (322) may be provided to seal the gap with the main body (10) when the second door (32) is closed.

[0183] Although not illustrated, the second door (32) may further include a configuration that is wholly or partially identical to the first door shelf (313) and the first shelf support (314) of the first door (31).

[0184] According to one embodiment, the refrigerator (1) may include a top table (13) provided on the upper part of the main body (10). The top table (13) may be coupled to the upper part of the outer housing (12). For example, the top table (13) may be coupled to the upper surface of the outer housing (12). For example, the top table (13) may be fixed to the outer housing (12).

[0185] According to one embodiment, the top table (13) can cover the hinge bracket (40) of the upper door. In this respect, the top table (13) can be named a hinge bracket cover.

[0186] According to one embodiment, the top table (13) can cover various electrical components. A receiving space for accommodating various electrical components may be formed on the inside of the top table (13). For example, the top table (13) can cover a door drive unit (not shown), and the door drive unit (not shown) may be accommodated on the inside of the top table (13).

[0187] Although the refrigerator (1) according to one embodiment of the present disclosure has been described as an example of the present disclosure on the premise that it is a cold-cooling refrigerator, the concept of the present disclosure is not limited thereto and can also be applied to a direct-cooling refrigerator.

[0188] Generally, thermoelectric elements may include thermoelectric legs classified into N-type and P-type. N-type thermoelectric legs can be provided as high-efficiency thermoelectric elements as their orientation and electrical conductivity are excellent. However, in the case of an N-type Peltier element having a hexagonal (HCP) crystal structure, the HCP crystal structure cannot uniformly control externally applied impact energy due to the c-axis having weak van der Waals bonds. This makes it difficult to utilize as a high-efficiency thermoelectric element, as the alloy material may be formed into powders with non-uniform powder sizes and irregular powder shapes when crushed.

[0189] A thermoelectric element according to one embodiment of the present disclosure can maximize the generation of plate-like particles with reduced c-axis brittleness through a plurality of specific crushing processes. Accordingly, a thermoelectric element with improved orientation and electrical conductivity can be provided.

[0190] A thermoelectric element according to one embodiment of the present disclosure can secure a high production speed and uniformity of powder by providing plate-shaped alloy powder using a plurality of simple crushing processes.

[0191] A thermoelectric element according to one embodiment of the present disclosure forms a sintered body combined with plate-shaped alloy powder, thereby improving internal stress and, accordingly, can provide stable and efficient thermoelectric performance to home appliances (e.g., refrigerators).

[0192] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0193] A method for manufacturing a thermoelectric element (100) according to one embodiment of the present disclosure comprises: a process for preparing a Bi-Te alloy material, wherein the Bi-Te alloy material (510) contains selenium (Se) in a range of 0.1 to 0.5 mol.% based on total molar amount; a process for first crushing the Bi-Te alloy material (510), wherein the Bi-Te alloy material (510) is crushed through a gap of 1 mm to 5 mm set between a pair of crushing plates (611) to form an alloy piece having a first length (L1); and a process for second crushing the first crushed alloy piece (520), wherein the alloy piece (520) is crushed through a gap of 0.1 mm to 10 mm set between a pair of disks (621) to form a plate-shaped alloy powder (530) having a second length (L2) smaller than the first length (L1). It can be included.

[0194] According to one embodiment, in the second grinding process, among the pair of disks (621) facing each other, the first disk (621a) may be in a stationary state and the second disk (621b) may be in a rotating state. The rotational speed of the second disk (621b) may be set to 440 RPM to form plate-shaped alloy powder (530).

[0195] According to one embodiment, the first length (L1) of the first crushed alloy piece (520) may be 20 mm to 40 mm.

[0196] According to one embodiment, the second length (L2) of the second crushed plate-shaped alloy powder (530) may be 200 μm or less.

[0197] According to one embodiment, the size of the Bi-Te alloy material (510) may have a diameter (Φ) of 25 mm to 40 mm and a length (L) of 50 mm to 300 mm.

[0198] According to one embodiment, a method for manufacturing a thermoelectric element (100) may further include a process of classifying the plate-shaped alloy powder (530) according to size, and a process of forming the classified plate-shaped alloy powder (530) into a sintered material by press molding and hot extrusion to form a thermoelectric leg (110) for the thermoelectric element.

[0199] According to one embodiment, by a process of forming a sintered body from the classified plate-shaped alloy powder (530), the crystal grains of the sintered body (540) can be configured to have an orientation arranged in parallel directions.

[0200] According to one embodiment, the grain size of each of the crystal grains of the sintered body (540) may be 2.0㎛ to 5.0㎛.

[0201] According to one embodiment, the power factor (PF) value of the sintered body (540) may be 3.7 or higher on average.

[0202] According to one embodiment, in the first grinding process, the amount of the Bi-Te alloy material (510) to be fed between the grinding plates (611) can be 50g to 200g.

[0203] According to one embodiment, in the secondary crushing process, the amount of alloy piece (520) to be fed between the discs (621) can be 50g to 200g.

[0204] A refrigerator (1) according to one embodiment of the present disclosure may include a main body (10), a door (30) rotatably connected to open and close the main body, a storage room (20) disposed inside the main body for storing food, and a cold air supply device configured to supply cold air to the storage room and including a thermoelectric element (100). The thermoelectric element (100) may include a Bi-Te-based thermoelectric leg (110). The Bi-Te-based thermoelectric leg (110) may contain selenium (Se) in a range of 0.1 to 0.5 mol.% based on the total molar amount. The Bi-Te-based thermoelectric leg (110) is a sintered body (540) composed of plate-shaped alloy powders (530), and the length of each of the plate-shaped alloy powders (530) for forming the sintered body may be 200 μm or less.

[0205] According to one embodiment, each of the alloy powders (530) including the Bi-Te-based thermoelectric leg may include plate-shaped particles (531) and a plurality of fine particles (532) in which at least a portion is inserted on the surface of the plate-shaped particles (531).

[0206] According to one embodiment, the length of each of the plurality of fine particles (532) may be 500 nm to 1 µm.

[0207] According to one embodiment, the Bi-Te-based thermoelectric leg (110) can form an N-type thermoelectric leg.

[0208] According to one embodiment, the crystal grains of the sintered body (540) may be configured to have an orientation arranged in parallel directions.

[0209] According to one embodiment, the PF value of the sintered body (540) may be 3.7 or higher on average.

[0210] According to one embodiment, the grain size of each of the crystal grains of the sintered body (540) may be 2.0㎛ to 5.0㎛.

[0211] According to one embodiment, the alloy powders (530) constituting the sintered body can be formed through a plurality of grinding processes.

[0212] A thermoelectric element (100) according to one embodiment of the present disclosure may include a Bi-Te-based thermoelectric leg (110). The Bi-Te-based thermoelectric leg (110) may include selenium (Se) in a range of 0.1 to 0.5 mol.% based on the total molar amount. The Bi-Te-based thermoelectric leg (110) is a sintered body composed of plate-shaped alloy powders (530), and the length of each of the plate-shaped alloy powders (530) for forming the sintered body may be 200 μm or less.

Claims

1. In a method for manufacturing a thermoelectric element (100), A process for preparing a Bi-Te alloy material, wherein the Bi-Te alloy material (510) comprises selenium (Se) in a range of 0.1 to 0.5 mol.% based on total molar amount; A process for first crushing the above Bi-Te alloy material (510), wherein the Bi-Te alloy material (510) is crushed through a gap of 1 mm to 5 mm set between a pair of crushing plates (611) to form an alloy piece having a first length (L1); and A method for manufacturing a thermoelectric element, comprising a process of secondarily crushing the first crushed alloy piece (520), wherein the alloy piece (520) is crushed through a gap of 0.1 mm to 10 mm set between a pair of disks (621) to form a plate-shaped alloy powder (530) having a second length (L2) smaller than the first length (L1).

2. In Paragraph 1, In the above second crushing process, among the pair of disks (621) facing each other, the first disk (621a) is in a stationary state, and the second disk (621b) is in a rotating state. A method for manufacturing a thermoelectric element, wherein the rotational speed of the second disk (621b) is set to 440 RPM to form a plate-shaped alloy powder (530).

3. In Paragraph 1 or 2, A method for manufacturing a thermoelectric element, wherein the first length (L1) of the first crushed alloy piece (520) is 20 mm to 40 mm.

4. In any one of paragraphs 1 to 3, A method for manufacturing a thermoelectric element, wherein the second length (L2) of the second crushed plate-shaped alloy powder (530) is 200 μm or less.

5. In any one of paragraphs 1 through 4, A method for manufacturing a thermoelectric element, wherein the size of the above Bi-Te alloy material (510) is a diameter (Φ) of 25 mm to 40 mm and a length (L) of 50 mm to 300 mm.

6. In any one of paragraphs 1 through 5, A process of classifying the above plate-shaped alloy powder (530) according to size; and A method for manufacturing a thermoelectric element, further comprising the process of forming the above-described classified plate-shaped alloy powder (530) into a sintered body (sintered material) by press molding and hot extrusion to form a thermoelectric leg (110) for a thermoelectric element.

7. In Paragraph 6, A method for manufacturing a thermoelectric element, wherein the crystal grains of the sintered body (540) are configured to have an orientation arranged in parallel directions by a process of forming a sintered body from the above-described plate-shaped alloy powder (530).

8. In Paragraph 6 or 7, A method for manufacturing a thermoelectric element, wherein the grain size of each crystal grain of the above-mentioned sintered body (540) is 2.0㎛ to 5.0㎛.

9. In any one of paragraphs 6 through 8, A method for manufacturing a thermoelectric element, wherein the PF (power factor) value of the above-mentioned sintered body (540) is 3.7 or higher on average.

10. In any one of paragraphs 1 through 9, A method for manufacturing a thermoelectric element, wherein in the first crushing process above, the amount of the Bi-Te alloy material (510) to be introduced between the crushing plates (611) is 50g to 200g.

11. In any one of paragraphs 1 through 10, A method for manufacturing a thermoelectric element, wherein in the above secondary crushing process, the amount of alloy piece (520) to be inserted between the disks (621) is 50g to 200g.

12. In the refrigerator (1), Main body (10); A door (30) rotatably connected to open and close the main body; A storage room (20) disposed inside the main body and for storing food; and A cold air supply device configured to supply cold air to the above storage room and including a thermoelectric element (100), The above thermoelectric element (100) includes a Bi-Te-based thermoelectric leg (110), and The above Bi-Te-based thermoelectric leg (110) contains selenium (Se) in a range of 0.1 to 0.5 mol.% based on total moles, and The above Bi-Te-based thermoelectric leg (110) is a sintered body (540) composed of plate-shaped alloy powders (530), and the length of each of the plate-shaped alloy powders (530) for forming the sintered body is 200 μm or less, a refrigerator.

13. In Paragraph 12, Each of the alloy powders (530) containing the above Bi-Te-based thermoelectric leg is, A refrigerator comprising plate-shaped particles (531) and a plurality of fine particles (532) with at least a portion inserted on the surface of the plate-shaped particles (531).

14. In Paragraph 12 or 13, A refrigerator in which the length of each of the plurality of fine particles (532) is 500 nm to 1 µm.

15. In any one of paragraphs 12 through 14, The above Bi-Te thermoelectric leg (110) forms an N-type thermoelectric leg, in a refrigerator.

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