Search

CN-121985719-A - Preparation method of bismuth telluride-based thermoelectric film material

CN121985719ACN 121985719 ACN121985719 ACN 121985719ACN-121985719-A

Abstract

Aiming at the defect that the existing bismuth telluride system materials mostly exist in a rigid form and limit the application of the bismuth telluride system materials in the emerging fields of wearable equipment, flexible electronic devices and the like, the invention realizes the flexibility of the bismuth telluride material by embedding micron-sized bismuth telluride powder into a flexible matrix of polyimide, breaks the limitation of the traditional thermoelectric materials in application scenes, provides an innovative thermoelectric management solution for flexible electronic products, and has certain commercial and technical values.

Inventors

  • ZHOU SHUAI
  • WU YANQING

Assignees

  • 上海申和投资有限公司

Dates

Publication Date
20260505
Application Date
20251211

Claims (9)

  1. 1. The preparation method of the bismuth telluride-based thermoelectric film material is characterized by comprising the following steps of: (1) Respectively preparing bismuth telluride micron-sized powder and polystyrene sulfonic acid (PSS) dispersion liquid with the concentration of 1-5 wt%, uniformly dispersing the bismuth telluride powder in the PSS dispersion liquid, fully mixing, adding a dispersing agent polyvinylpyrrolidone (PVP), and carrying out mechanical stirring and ultrasonic dispersion under the protection of inert gas to obtain uniform composite slurry; (2) Coating the composite slurry on a pretreated PET substrate by a spraying method, controlling the film thickness to be 2-15 mu m, carrying out heat treatment for 20-40 min at 70-110 ℃, removing the solvent and forming a compact film, and carrying out low-temperature annealing treatment on the formed film at 120-180 ℃ under the condition of oxygen isolation to obtain the bismuth telluride-based thermoelectric film material.
  2. 2. The method for preparing a bismuth telluride-based thermoelectric thin film material according to claim 1, wherein: Wherein, in the step (1), the preparation method of the bismuth telluride micron-sized powder comprises the steps of mixing three simple substance raw materials of Sb, bi and Te, vacuum melting to obtain cast ingots, crushing and ball milling to obtain the bismuth telluride micron-sized powder, Bi. The mol ratio of the Sb to the Te is 0.4:1.6:3, and the purities of the Bi, the Sb and the Te are 99.999 percent.
  3. 3. The method for preparing a bismuth telluride-based thermoelectric thin film material according to claim 2, wherein: Uniformly mixing three simple substances of Bi, sb and Te, placing the mixed simple substances in a graphite crucible, placing the graphite crucible in a quartz tube, vacuumizing the quartz tube, packaging for vacuum melting, heating to 700-800 ℃ at a heating rate of 10 ℃ per min under the vacuum degree of 0.01Pa, preserving heat for at least 6 hours, and cooling to room temperature; during crushing, ball milling is performed under the protection of argon, the rotating speed is set to 300-400 rpm, and the ball milling time is 10-60 min, so that micron-sized bismuth telluride powder is formed.
  4. 4. The method for preparing a bismuth telluride-based thermoelectric thin film material according to claim 1, wherein: The preparation method of the PSS dispersion liquid in the step (1) comprises the steps of selecting PSS as a conductive polymer, dissolving the conductive polymer in ethanol to prepare the PSS dispersion liquid with the concentration of 1-5 wt%, and then adding an ethylene glycol cosolvent to form a uniform dispersion liquid through ultrasonic treatment.
  5. 5. The method for preparing a bismuth telluride-based thermoelectric thin film material according to claim 4, wherein: Wherein, the mass fraction of the glycol in the PSS dispersion is 0.05-0.2%, the power of the ultrasonic treatment is 100-200W, and the time is 20-40 min.
  6. 6. The method for preparing a bismuth telluride-based thermoelectric thin film material according to claim 1, wherein: In the step (1), the preparation method of the composite slurry comprises the steps of mixing bismuth telluride micron powder and PSS dispersion liquid according to a mass ratio of 1:0.3-1.5, and adding a dispersing agent polyvinylpyrrolidone PVP with a mass fraction of 0.1-0.3%; Under the protection of nitrogen, the stirring is carried out under the conditions of 300-500 rpm of mechanical stirring and 1h of ultrasonic dispersion, wherein the power is 150~250 W,30~60min, and the uniform composite slurry is prepared.
  7. 7. The method for preparing a bismuth telluride-based thermoelectric thin film material according to claim 1, wherein: in the step (2), the pretreatment method of the PET substrate is that the PET substrate is subjected to plasma treatment under the conditions of 50-100W of power and 1-8 min of time, so that the surface hydrophilicity and the adhesive force are improved.
  8. 8. The method for preparing a bismuth telluride-based thermoelectric thin film material according to claim 1, wherein: in the step (2), when the composite slurry is coated on a pretreated PET substrate by a spraying method, the nozzle pressure is 0.1-0.3 MPa; The low-temperature annealing treatment is carried out under the conditions that 120-180 ℃ is treated for 1-2 hours under the protection of nitrogen atmosphere.
  9. 9. A bismuth telluride-based thermoelectric thin film material, characterized in that it is prepared by the method of any one of claims 1 to 8.

Description

Preparation method of bismuth telluride-based thermoelectric film material Technical Field The invention belongs to the technical field of thermoelectric materials, and particularly relates to a preparation method of a bismuth telluride-based thermoelectric film material. Background Bismuth telluride is one of the most widely used thermoelectric materials at present, and is mainly used in thermoelectric power generation and thermoelectric refrigeration devices. Bismuth telluride is one of the best choices in the medium and low temperature range due to its excellent thermoelectric properties, particularly the high thermoelectric figure of merit exhibited near room temperature. In conventional applications, bismuth telluride is usually present in the form of bulk materials and is prepared by complex processes such as high temperature sintering or crystal growth. Such rigid materials are widely used in the fields of power management, temperature control systems, local thermal management, and the like. However, with the development of electronic products to flexible, portable and wearable devices, the conventional rigid thermoelectric materials gradually expose some limitations, such as mechanical performance limitation, complex preparation process, high integration difficulty, limited application scenario and the like. Thermoelectric materials such as bismuth telluride often exhibit rigidity or brittleness, which makes it difficult to accommodate the flexibility requirements of modern flexible electronic devices. Emerging fields of wearable devices, smart apparel, flexible sensors, etc. require materials that can maintain stable performance under bending, stretching, and even twisting conditions, whereas traditional bulk bismuth telluride materials are prone to cracking or failure in such applications. Conventional bismuth telluride thermoelectric materials are mostly prepared by high temperature sintering or crystal growth techniques, which require high energy consumption, high cost, and strict requirements for equipment and process control, are not suitable for large-scale, low-cost manufacturing, which limits the popularization of the materials in large-scale commercial applications. Furthermore, rigid bismuth telluride materials are difficult to integrate with flexible electronic devices, particularly in miniaturized or miniaturized applications, the rigidity of the material makes it difficult to adhere or bond tightly on complex shapes or surfaces, affecting the performance and reliability of the device. Meanwhile, although bismuth telluride material is excellent in the conventional thermoelectric field, its rigidity limits its wide application in fields such as smart wearable devices, flexible energy management devices, and the like. Therefore, there is a need in the art for a composite material that can maintain the efficient thermoelectric conversion performance of bismuth telluride and that can stably operate in a complex, flexible structure to address the increasing demands in the flexible electronic device and wearable technology fields. Disclosure of Invention The invention provides a preparation method of bismuth telluride-based thermoelectric film material for solving the problems. Compounding bismuth telluride micron-sized powder with PSS, and optimizing conductivity and Seebeck coefficient; then combining with the flexible matrix PET subjected to hydrophilization pretreatment, and adopting a solution spin-coating method to prepare the flexible thermoelectric material, thereby providing a preparation method which simplifies the preparation process, has low cost and is easy for mass production. The specific technical scheme of the invention is as follows: in a first aspect, the present invention provides a method for preparing a bismuth telluride-based thermoelectric thin film material, comprising the steps of: (1) Respectively preparing bismuth telluride micron-sized powder and polystyrene sulfonic acid (PSS) dispersion liquid with the concentration of 1-5 wt%, uniformly dispersing the bismuth telluride powder in the PSS dispersion liquid, fully mixing, adding a dispersing agent polyvinylpyrrolidone (PVP), and carrying out mechanical stirring and ultrasonic dispersion under the protection of inert gas to obtain uniform composite slurry; (2) Coating the composite slurry on a pretreated PET substrate by a spraying method, controlling the film thickness to be 2-15 mu m, carrying out heat treatment for 20-40 min at 70-110 ℃, removing the solvent and forming a compact film, and carrying out low-temperature annealing treatment on the formed film at 120-180 ℃ under the condition of oxygen isolation to obtain the bismuth telluride-based thermoelectric film material. Preferably, in the step (1), the molar ratio of the Bi, the Sb and the Te is 0.4:1.6:3, and the purities of the Bi, the Sb and the Te are 99.999 percent. The operation of vacuum melting to obtain cast ingot is that mixing Bi, sb and Te eleme