Bismuth telluride-based alloy / carbon cloth thermoelectric composite material and preparation method thereof
By electrochemically depositing bismuth telluride-based alloy on the surface of carbon cloth and performing annealing treatment, the prepared bismuth telluride-based alloy/carbon cloth thermoelectric composite material solves the contradiction between flexibility and thermoelectric performance, realizes the possibility of self-powering flexible electronic devices, improves thermoelectric performance and simplifies the production process.
Patent Information
- Application Number
- CN202210078322.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-01-24
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2042-01-24
AI Technical Summary
Existing thermoelectric composite materials are difficult to simultaneously meet the requirements of flexibility and thermoelectric performance. In particular, the poor flexibility of bismuth telluride alloys limits their application in flexible power generation.
Bismuth telluride-based alloy is uniformly deposited on the surface and pores of carbon cloth by electrochemical deposition technology, and annealing treatment is performed to prepare bismuth telluride-based alloy/carbon cloth thermoelectric composite material.
The prepared bismuth telluride-based alloy/carbon cloth thermoelectric composite material significantly improves the thermoelectric performance while maintaining good flexibility. The electrochemical deposition method is simple to operate and highly controllable, making it suitable for commercial-scale production.
Smart Images
Figure CN114464724B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of thermoelectric composite materials, and in particular relates to a bismuth telluride-based alloy / carbon cloth thermoelectric composite material. Background Art
[0002] Electronic devices are currently developing towards being soft and lightweight. Currently, smartphones with flexible screens, watches, and electronic skin for vital sign monitoring have been successfully commercialized on the market. However, flexible electronics are currently powered by traditional batteries, which require disassembly, cyclical charging and discharging, etc., causing considerable inconvenience. In particular, for electronic devices implanted in the body, disassembly can also pose safety risks. If flexible electronic devices can be self-powered, it can bring great convenience and reduce safety risks. Thermoelectric materials can directly convert body temperature heat energy into electrical energy based on the Seebeck effect of semiconductors, thereby powering electronic devices. This power supply method does not require moving components, so it is safe, noiseless, and extremely easy to miniaturize, so it has broad market prospects.
[0003] The thermoelectric performance of thermoelectric materials can be evaluated by the dimensionless thermoelectric figure of merit ZT=S2σT / κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity, and T is the absolute temperature. Bismuth telluride alloy is the material with the best thermoelectric performance at room temperature, but because its constituent atoms are bonded by covalent bonds or ionic bonds, its flexibility is poor, so its application in flexible power generation is limited. The overall flexibility can be optimized by combining materials with excellent thermoelectric properties with materials with excellent flexibility. Carbon cloth is soft, lightweight and has good conductivity, and is often used to prepare batteries and supercapacitors. The literature (Alloy Compd, 2021, 868: 158905-158915) coats bismuth telluride slurry on the surface of carbon cloth to synergistically optimize the thermoelectric performance and flexibility of the composite material, but this method is complicated to operate, and the resulting composite material inevitably contains organic matter, so the improvement in thermoelectric performance is small. Summary of the Invention
[0004] The present invention addresses the technical problem that thermoelectric composite materials in the prior art cannot simultaneously meet the requirements of flexibility and thermoelectric performance, and aims to provide a new thermoelectric composite material.
[0005] The present invention uses pretreated carbon cloth as a working electrode. A bismuth telluride-based alloy is uniformly deposited on the surface and pores of the carbon cloth through electrochemical deposition, followed by annealing to produce a bismuth telluride-based alloy / carbon cloth thermoelectric composite material. The resulting bismuth telluride-based alloy / carbon cloth thermoelectric composite material exhibits excellent flexibility and thermoelectric performance. Furthermore, the electrochemical deposition technique employed is simpler, more controllable, and faster than other preparation methods, making it suitable for commercial-scale production.
[0006] The bismuth telluride-based alloy / carbon cloth thermoelectric composite material of the present invention is characterized in that the mass ratio of the bismuth telluride-based alloy in the thermoelectric composite material is 15-99%, preferably 60-88%, and the mass ratio of the carbon cloth in the thermoelectric composite material is 1-85%, preferably 12-40%.
[0007] Wherein, the bismuth telluride-based alloy is Bi x Sb 2-x Te3 or Bi2Se y Te 3-y , where 0≤x≤2, 0≤y≤3.
[0008] Another object of the present invention is to provide a method for preparing the bismuth telluride-based alloy / carbon cloth thermoelectric composite material of the present invention, comprising the following steps in sequence:
[0009] Step S1, electrochemical deposition: placing carbon cloth as a working electrode, an auxiliary electrode, and a reference electrode into an electrolyte containing a bismuth telluride-based alloy raw material for electrochemical deposition to obtain a bismuth telluride-based alloy / carbon cloth thermoelectric composite material;
[0010] Step S2, annealing: annealing the bismuth telluride-based alloy / carbon cloth thermoelectric composite material in a protective atmosphere to obtain a final bismuth telluride-based alloy / carbon cloth thermoelectric composite material.
[0011] Preferably, the following steps are further included before step S1:
[0012] Step Sa, preparing an electrolyte: weighing a tellurium-containing compound, a bismuth-containing compound, and an antimony-containing compound raw materials in proportion and adding them to a 0.5-3 mol / L nitric acid aqueous solution, and stirring them thoroughly under heating until the solution becomes clear to obtain an electrolyte containing a bismuth telluride-based alloy raw material; wherein the molar ratio of the tellurium-containing compound: the sum of the bismuth-containing compound and the antimony-containing compound is 1: (0.8-7), and the concentration of the tellurium-containing compound in the nitric acid aqueous solution is 5-20 mmol / L; wherein the molar ratio of the bismuth-containing compound: the sum of the tellurium-containing compound and the selenium-containing compound is 1: (0.6-1.4), and the concentration of the bismuth-containing compound in the nitric acid aqueous solution is 5-20 mmol / L.
[0013] Step Sb, pretreatment of the working electrode: ultrasonically clean the carbon cloth with acetone, hydrochloric acid solution, and deionized water in sequence, and vacuum dry it before use as the working electrode.
[0014] There is no order of priority between step Sa and step Sb.
[0015] In step Sa, the tellurium-containing compound is any one or a combination of two or more of tellurium dioxide, sodium tellurite, and potassium tellurite; the bismuth-containing compound is any one or a combination of bismuth nitrate pentahydrate and bismuth oxide; the antimony-containing compound is any one or a combination of antimony trioxide and antimony chloride; and the selenium-containing compound is any one or a combination of two or more of selenious acid, sodium selenite, and selenium dioxide; if the antimony-containing compound raw material is weighed, the antimony ion complexing agent raw material is weighed at the same time, and the antimony ion complexing agent is any one or a combination of tartaric acid and sodium citrate; the molar ratio of the antimony ion complexing agent to the antimony ion is (3 to 100):1, preferably (4 to 40):1.
[0016] Preferably, in step Sa, the mixture is heated to 20-90° C., preferably 40-60° C., and stirred at a stirring rate of 30-1000 r / min, preferably 50-600 r / min, until the solution becomes clear.
[0017] In step Sb, the carbon cloth is sequentially cleaned with acetone, a 0.5-5 mol / L preferably 1-2 mol / L hydrochloric acid aqueous solution, and deionized water at 20-30 kHz ultrasonic cleaning for 1-30 min, preferably 5-10 min, and dried at 30-90° C., preferably 50-60° C., under a vacuum degree of 0.5-25 Pa for 3-12 h before being used as a working electrode.
[0018] Preferably, in step S1: a carbon cloth is used as a working electrode, a platinum sheet or platinum wire or platinum mesh or a high-purity carbon rod is used as an auxiliary electrode, and a saturated calomel electrode is used as a reference electrode and equidistantly placed in an electrolyte containing a bismuth telluride-based alloy raw material, and electrochemical deposition is performed under stirring at room temperature, and the deposited working electrode substrate is washed with distilled water and anhydrous ethanol, and vacuum dried to obtain a process bismuth telluride-based alloy / carbon cloth thermoelectric composite material; wherein the electrochemical deposition method includes constant potential electrodeposition, constant current electrodeposition and pulse electrodeposition, and its technical parameters are: deposition potential is -0.4 to 0.1V, preferably -0.3 to 0.06V, and deposition current is 1 to 30 mA cm -2 Preferably 10-20 mA cm -2 The pulse time in different stages is 0.01 to 50 s, preferably 0.01 to 10 s, and the total deposition time is 1 to 24 h, preferably 5 to 10 h.
[0019] Preferably, in step S1: carbon cloth is used as a working electrode, and a platinum sheet or platinum wire or platinum mesh or high-purity carbon rod is used as an auxiliary electrode, and a saturated calomel electrode is used as a reference electrode. The electrodes are placed in an electrolyte containing a bismuth telluride-based alloy raw material at an equal distance of 0.5 cm to 5 cm, preferably 1 cm. Electrochemical deposition is performed at room temperature at a stirring rate of 10 to 600 r / min, preferably 200 to 400 r / min. The deposited working electrode substrate is washed with distilled water and anhydrous ethanol 1 to 10 times, preferably 3 to 5 times, and dried at 30 to 90°C, preferably 50 to 60°C, under a vacuum degree of 0.5 to 25 Pa for 3 to 12 hours to obtain a process bismuth telluride-based alloy / carbon cloth thermoelectric composite material.
[0020] Preferably, in step S2: the protective atmosphere is nitrogen, argon, hydrogen, or an argon-hydrogen mixture containing 5% hydrogen by volume, and the annealing process parameters are: a heating rate of 3 to 40°C / min, preferably 4 to 10°C / min, a holding temperature of 200°C to 400°C, preferably 220°C to 300°C, and a holding time of 0.5 to 3h, preferably 0.5 to 1.5h.
[0021] The present invention discloses a method for preparing a bismuth telluride-based alloy / carbon cloth thermoelectric composite material by electrodeposition: pretreating the carbon cloth to remove surface contamination and render it hydrophilic; using the pretreated carbon cloth as a working electrode, and combining it with an auxiliary electrode, a reference electrode, and an electrolyte to form a three-electrode electrochemical system, which is prepared using electrochemical deposition technology; and subjecting the deposited composite thermoelectric material to a high-temperature annealing treatment to prepare the bismuth telluride-based alloy / carbon cloth thermoelectric composite material. The bismuth telluride-based alloy / carbon cloth thermoelectric composite material prepared by the present invention exhibits significantly improved thermoelectric performance compared to carbon cloth and its composite materials. Furthermore, the electrodeposition method employed is simpler to operate, more controllable, faster, and more suitable for commercial-scale production than other preparation methods.
[0022] The beneficial effects of the present invention are:
[0023] 1) The bismuth telluride-based alloy / carbon cloth thermoelectric composite material prepared by the present invention has good flexibility and exhibits excellent thermoelectric performance.
[0024] 2) In the bismuth telluride-based alloy / carbon cloth thermoelectric composite material prepared by the present invention, the bismuth telluride-based alloy is uniformly deposited on the surface and pores of the carbon cloth, and the mass of the bismuth telluride-based alloy accounts for 15-99% of the mass of the composite film.
[0025] 3) Compared with other methods, the electrodeposition method required for the preparation of the present invention is simple to operate, highly controllable, fast, and suitable for commercial-scale production. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1These are the X-ray diffraction patterns of the carbon cloth, the bismuth telluride / carbon cloth thermoelectric composite material, and the bismuth telluride / carbon cloth thermoelectric composite material in Example 1.
[0027] Figure 2 This is a scanning electron microscope image of the bismuth telluride / carbon cloth thermoelectric composite material in Example 1.
[0028] Figure 3 The electrical conductivity and Seebeck coefficient of the carbon cloth, the bismuth telluride / carbon cloth thermoelectric composite material, and the bismuth telluride / carbon cloth thermoelectric composite material in Example 1 are shown.
[0029] Figure 4 is the power factor of the carbon cloth, the process bismuth telluride / carbon cloth thermoelectric composite material, and the bismuth telluride / carbon cloth thermoelectric composite material in Example 1.
[0030] Figure 5 3 is a graph showing the relationship between the electrical conductivity of the bismuth telluride / carbon cloth thermoelectric composite material in Example 1 and the bending radius. DETAILED DESCRIPTION
[0031] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.
[0032] Examples 1 to 12
[0033] Preparation of Bismuth Telluride-based alloy / carbon cloth thermoelectric composite materials, with carbon cloth as a flexible conductive substrate, Bismuth Telluride-based alloy Bi x Sb 2-x Se y Te 3-y The specific steps of the method for preparing bismuth telluride / carbon cloth thermoelectric composite material by electrochemical deposition are as follows:
[0034] Step Sa, preparing an electrolyte: weighing a tellurium-containing compound, a bismuth-containing compound, an antimony-containing compound, a selenium-containing compound, and an antimony complexing agent, adding them to an aqueous nitric acid solution, stirring under heating until the solution becomes clear, and using the clear solution as the electrolyte for later use.
[0035] Step Sb, pretreatment of the working electrode: the carbon cloth is cut into a suitable size, and then ultrasonically cleaned in acetone, hydrochloric acid aqueous solution and deionized water in sequence, and then dried in a vacuum under heating. After drying, it is used as a working electrode.
[0036] Step S1, electrochemical deposition: A three-electrode system is used, with a platinum sheet of appropriate size as the auxiliary electrode, a saturated calomel electrode as the reference electrode, and the carbon cloth pretreated in step Sb as the working electrode. The three electrodes are equidistantly placed in the electrolyte prepared in step Sa. The electrolyte is stirred at room temperature, and deposition is performed using electrochemical deposition. The deposited working electrode substrate is repeatedly rinsed with distilled water and anhydrous ethanol, then dried in a vacuum under heating to obtain the bismuth telluride / carbon cloth thermoelectric composite material.
[0037] Step S2, annealing treatment: placing the bismuth telluride / carbon cloth thermoelectric composite material deposited in the above step S1 in an atmosphere furnace, slowly heating it to a certain temperature, and keeping it warm for a period of time to prepare a bismuth telluride-based alloy / carbon cloth thermoelectric composite material.
[0038] Table 1 Preparation process parameters of bismuth telluride-based alloy / carbon cloth thermoelectric composite materials of Examples 1 to 12
[0039]
[0040]
[0041] Table 1 (Continued) Preparation process parameters of bismuth telluride-based alloy / carbon cloth thermoelectric composite materials of Examples 1 to 12
[0042]
[0043]
[0044] Table 1 (Continued) Preparation process parameters of bismuth telluride-based alloy / carbon cloth thermoelectric composite materials of Examples 1 to 12
[0045]
[0046]
[0047]
[0048] Table 1 (Continued) Preparation process parameters of bismuth telluride-based alloy / carbon cloth thermoelectric composite materials of Examples 1 to 12
[0049]
[0050]
[0051] The X-ray diffraction patterns of the carbon cloth obtained in Example 1, the process bismuth telluride / carbon cloth thermoelectric composite material, and the final bismuth telluride / carbon cloth thermoelectric composite material after annealing are shown in FIG. Figure 1The XRD pattern of the carbon cloth shows only a hump at 27°, indicating that the carbon cloth substrate is an amorphous structure. The diffraction peaks of the process bismuth telluride / carbon cloth thermoelectric composite material completely match those of bismuth telluride (PDF#15-0863), with no other impurity peaks. The half-width of the diffraction peaks of the final annealed bismuth telluride / carbon cloth thermoelectric composite material is significantly smaller than that of the process bismuth telluride / carbon cloth thermoelectric composite material, indicating that annealing increases the bismuth telluride grain size.
[0052] The electron microscope scanning image of the final bismuth telluride / carbon cloth thermoelectric composite material after annealing obtained in Example 1 is shown in FIG. Figure 2 , the carbon fibers in the carbon cloth are wrapped with bismuth telluride.
[0053] The electrical conductivity and Seebeck coefficient of the carbon cloth, bismuth telluride / carbon cloth thermoelectric composite material, and annealed bismuth telluride / carbon cloth thermoelectric composite material obtained in Example 1 are shown in FIG. Figure 3 The electrical conductivity of bismuth telluride / carbon cloth thermoelectric composite material is 319S cm -1 Compared with the process bismuth telluride / carbon cloth thermoelectric composite material, it has increased by 0.5 times and compared with carbon cloth, it has increased by 8.5 times. The Seebeck coefficient of bismuth telluride / carbon cloth thermoelectric composite material is -38μVK -1 , and the Seebeck coefficient of the process bismuth telluride / carbon cloth thermoelectric composite material is -33.9μVK -1 Compared with carbon cloth, it is slightly improved and 5 times higher.
[0054] The power factors of the carbon cloth, bismuth telluride / carbon cloth thermoelectric composite material, and annealed bismuth telluride / carbon cloth thermoelectric composite material obtained in Example 1 are as follows: Figure 4 As shown. The power factor of bismuth telluride / carbon cloth thermoelectric composite material is 46μW K -2 m -1 Compared with the process, the bismuth telluride / carbon cloth thermoelectric composite material has increased by 1 times, and compared with the carbon step, it has increased by 400 times. From the above data, it can be seen that the thermoelectric performance of the bismuth telluride / carbon cloth thermoelectric composite material has been significantly improved compared with the carbon cloth.
[0055] The relationship between the conductivity of the annealed bismuth telluride / carbon cloth thermoelectric composite material obtained in Example 1 and the bending radius is as follows: Figure 5 As shown in Figure 2, when the bismuth telluride / carbon cloth thermoelectric composite material is bent at a radius of no less than 10 mm, the resistivity changes by less than 10%, and when the bending radius is no less than 8 mm, the resistivity changes by less than 20%. This indicates that the bismuth telluride / carbon cloth thermoelectric composite material has good flexibility.
[0056] The bismuth telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 2 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 39μW K at room temperature. -2 m-1 The resistivity of the bismuth telluride / carbon cloth bismuth thermoelectric composite material changes by less than 10% when the bending radius is not less than 9 mm, and by less than 20% when the bending radius is not less than 7 mm.
[0057] The antimony telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 3 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 21 μW K at room temperature. -2 m -1 When the antimony telluride / carbon cloth thermoelectric composite material has a bending radius of not less than 13 mm, the resistivity change is less than 10%, and when the bending radius is not less than 10 mm, the resistivity change is less than 20%.
[0058] The bismuth telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 4 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 36 μW K at room temperature. -2 m -1 The resistivity of the bismuth telluride / carbon cloth bismuth thermoelectric composite material changes by less than 10% when the bending radius is not less than 8 mm, and by less than 20% when the bending radius is not less than 7 mm.
[0059] The antimony telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 5 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 45 μW K at room temperature. -2 m -1 When the antimony telluride / carbon cloth thermoelectric composite material has a bending radius of not less than 12 mm, the resistivity change is less than 10%, and when the bending radius is not less than 9 mm, the resistivity change is less than 20%.
[0060] The antimony telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 6 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 0.6 μW K at room temperature. -2 m -1 When the antimony telluride / carbon cloth thermoelectric composite material has a bending radius of not less than 5 mm, the resistivity change is less than 10%, and when the bending radius is not less than 4 mm, the resistivity change is less than 20%.
[0061] The bismuth telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 7 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 85 μW K at room temperature. -2 m -1The resistivity of the bismuth telluride / carbon cloth bismuth thermoelectric composite material changes by less than 10% when the bending radius is not less than 10 mm, and by less than 20% when the bending radius is not less than 7 mm.
[0062] The antimony telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 8 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 96 μW K at room temperature. -2 m -1 When the antimony telluride / carbon cloth thermoelectric composite material has a bending radius of not less than 14 mm, the resistivity change is less than 10%, and when the bending radius is not less than 10 mm, the resistivity change is less than 20%.
[0063] The antimony telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 9 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 3μW K at room temperature. -2 m -1 When the antimony telluride / carbon cloth thermoelectric composite material has a bending radius of not less than 6 mm, the resistivity change is less than 10%, and when the bending radius is not less than 4 mm, the resistivity change is less than 20%.
[0064] The bismuth telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 10 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 4 μW K at room temperature. -2 m -1 The resistivity of the bismuth telluride / carbon cloth bismuth thermoelectric composite material changes by less than 10% when the bending radius is not less than 9 mm, and by less than 20% when the bending radius is not less than 7 mm.
[0065] The antimony telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 11 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 13 μW K at room temperature. -2 m -1 When the antimony telluride / carbon cloth thermoelectric composite material has a bending radius of not less than 11 mm, the resistivity change is less than 10%, and when the bending radius is not less than 8 mm, the resistivity change is less than 20%.
[0066] The antimony telluride / carbon cloth bismuth thermoelectric composite material obtained in Example 12 has significantly improved electrical conductivity and Seebeck coefficient compared to the flexible conductive carbon cloth, thereby greatly improving the thermoelectric performance, and the power factor is 0.5 μW K at room temperature. -2 m -1 When the antimony telluride / carbon cloth thermoelectric composite material has a bending radius of not less than 5 mm, the resistivity change is less than 10%, and when the bending radius is not less than 4 mm, the resistivity change is less than 20%.
[0067] All documents mentioned in this application are incorporated herein by reference, just as if each document were incorporated herein by reference individually. The above embodiments provide a detailed description of the technical solutions of the present invention. Obviously, the present invention is not limited to the described embodiments. Based on the embodiments of the present invention, those skilled in the art may make various modifications accordingly. However, any modifications that are equivalent or similar to the present invention fall within the scope of protection of the present invention.
Claims
1. A bismuth telluride-based alloy / carbon cloth thermoelectric composite material, characterized in that: The bismuth telluride-based alloy / carbon cloth thermoelectric composite material is a bismuth telluride-based alloy-carbon cloth thermoelectric composite material having bismuth telluride-wrapped carbon fibers, obtained by electrochemical deposition and annealing of an electrolyte containing carbon cloth and bismuth telluride-based alloy raw materials. The mass ratio of the bismuth telluride-based alloy in the thermoelectric composite material is 15-99%, and the mass ratio of the carbon cloth in the thermoelectric composite material is 1-85%.
2. The bismuth telluride-based alloy / carbon cloth thermoelectric composite material according to claim 1, wherein: The mass ratio of the bismuth telluride-based alloy in the thermoelectric composite material is 60% to 88%, and the mass ratio of the carbon cloth in the thermoelectric composite material is 12% to 40%.
3. The bismuth telluride-based alloy / carbon cloth thermoelectric composite material according to claim 1, wherein: The bismuth telluride-based alloy is Bi x Sb 2-x Te3 or Bi2Se y Te 3-y , where 0≤x≤2, 0≤y≤3.
4. A method for preparing the bismuth telluride-based alloy / carbon cloth thermoelectric composite material according to claim 1, characterized in that: The steps are as follows: Step S1, electrochemical deposition: placing carbon cloth as a working electrode, an auxiliary electrode, and a reference electrode into an electrolyte containing a bismuth telluride-based alloy raw material for electrochemical deposition to obtain a bismuth telluride-based alloy / carbon cloth thermoelectric composite material; Step S2, annealing: annealing the bismuth telluride-based alloy / carbon cloth thermoelectric composite material in a protective atmosphere to obtain a final bismuth telluride-based alloy / carbon cloth thermoelectric composite material.
5. The method according to claim 4, wherein Before step S1, the following steps are also included: Step Sa, preparing an electrolyte: weighing a tellurium-containing compound, a bismuth-containing compound, an antimony-containing compound, and a selenium-containing compound in proportion, adding the raw materials to a 0.5-3 mol / L nitric acid aqueous solution, and stirring thoroughly under heating until the solution becomes clear, to obtain an electrolyte containing a bismuth telluride-based alloy raw material; wherein the molar ratio of the tellurium-containing compound: the sum of the bismuth-containing compound and the antimony-containing compound is 1:(0.8-7), and the concentration of the tellurium-containing compound in the nitric acid aqueous solution is 5-20 mmol / L; wherein the molar ratio of the bismuth-containing compound: the sum of the tellurium-containing compound and the selenium-containing compound is 1:(0.6-1.4), and the concentration of the bismuth-containing compound in the nitric acid aqueous solution is 5-20 mmol / L; Step Sb, pretreatment of the working electrode: ultrasonically clean the carbon cloth with acetone, hydrochloric acid solution, and deionized water in sequence, and vacuum dry it before use as the working electrode.
6. The method according to claim 5, wherein In step Sa, the tellurium-containing compound is any one or a combination of two or more of tellurium dioxide, sodium tellurite, and potassium tellurite; the bismuth-containing compound is any one or a combination of two of bismuth nitrate pentahydrate and bismuth oxide; the antimony-containing compound is any one or a combination of two of antimony trioxide and antimony chloride; and the selenium-containing compound is any one or a combination of two or more of selenious acid, sodium selenite, and selenium dioxide; if the antimony-containing compound raw material is weighed, the antimony ion complexing agent raw material is weighed at the same time, and the antimony ion complexing agent is any one or a combination of tartaric acid and sodium citrate, and the molar ratio of the antimony ion complexing agent to the antimony ion is (3-100):
1.
7. The method according to claim 6, wherein The molar ratio of the antimony ion complexing agent to the antimony ion is (4-40):
1.
8. The method according to claim 5, wherein Step Sa, heating to 20-90° C. and stirring at a rate of 30-1000 r / min until the solution becomes clear; In step Sb, the carbon cloth is sequentially cleaned with acetone, 0.5-5 mol / L hydrochloric acid aqueous solution, and deionized water at 20-30 kHz ultrasonic cleaning for 1-30 min, and dried at 30-90° C. under a vacuum degree of 0.5-25 Pa for 3-12 h before being used as a working electrode.
9. The method according to claim 8, wherein Step Sa, heating to 40-60° C. and stirring at a rate of 50-600 r / min until the solution becomes clear; In step Sb, the carbon cloth is sequentially cleaned with acetone, 1-2 mol / L hydrochloric acid aqueous solution, and deionized water at 20-30 kHz ultrasonic cleaning for 5-10 minutes, and dried at 50-60° C. under a vacuum degree of 0.5-25 Pa for 3-12 hours before being used as a working electrode.
10. The method according to claim 4, wherein In step S1: a carbon cloth is used as a working electrode, a platinum sheet or platinum wire or platinum mesh or a high-purity carbon rod is used as an auxiliary electrode, and a saturated calomel electrode is used as a reference electrode. They are equidistantly placed in an electrolyte containing a bismuth telluride-based alloy raw material, and electrochemical deposition is performed under stirring at room temperature. The deposited working electrode substrate is washed with distilled water and anhydrous ethanol, and vacuum dried to obtain a process bismuth telluride-based alloy / carbon cloth thermoelectric composite material; wherein the electrochemical deposition method includes constant potential electrodeposition method, constant current electrodeposition method and pulse electrodeposition method, and its technical parameters are: deposition potential is -0.4~0.1V, deposition current is 1~30mAcm -2 The pulse time in different stages is 0.01~50s, and the total deposition time is 1~24h.
11. The method according to claim 10, wherein The deposition potential is -0.3~0.06V, and the deposition current is 10~20mAcm -2 The pulse time in different stages is 0.01~10s, and the total deposition time is 5~10h.
12. The method according to claim 10, wherein In step S1: carbon cloth is used as a working electrode, a platinum sheet or platinum wire or platinum mesh or a high-purity carbon rod is used as an auxiliary electrode, and a saturated calomel electrode is used as a reference electrode. They are placed in an electrolyte containing a bismuth telluride-based alloy raw material at an equal distance of 0.5 cm to 5 cm, and electrochemical deposition is performed at room temperature at a stirring rate of 10 to 600 r / min. The deposited working electrode substrate is washed 1 to 10 times with distilled water and anhydrous ethanol, and dried at 30 to 90° C. for 3 to 12 hours under a vacuum degree of 0.5 to 25 Pa to obtain a process bismuth telluride-based alloy / carbon cloth thermoelectric composite material.
13. The method according to claim 12, wherein Carbon cloth was used as the working electrode, platinum sheet or platinum wire or platinum mesh or high-purity carbon rod was used as the auxiliary electrode, and saturated calomel electrode was used as the reference electrode. They were placed 1 cm apart in an electrolyte containing bismuth telluride-based alloy raw material, and electrochemical deposition was carried out at room temperature with a stirring rate of 200-400 r / min. The deposited working electrode substrate was washed with distilled water and anhydrous ethanol 3-5 times, and dried at 50-60°C under a vacuum of 0.5-25 Pa for 3-12 hours to obtain the process bismuth telluride-based alloy / carbon cloth thermoelectric composite material.
14. The method according to claim 4, wherein In step S2, the protective atmosphere is nitrogen, argon, hydrogen, or an argon-hydrogen mixture containing 5% hydrogen by volume. The annealing process parameters are: a heating rate of 3-40°C / min, a holding temperature of 200-400°C, and a holding time of 0.5-3h.
15. The method according to claim 14, wherein In step S2, the annealing process parameters are: heating rate of 4-10°C / min, holding temperature of 220-300°C, and holding time of 0.5-1.5h.