Wearable thermoelectric generator with self-healing function and preparation method thereof

Abstract

The application provides a wearable thermoelectric generator with a self-healing function and a preparation method thereof, the preparation method adopts aluminum chloride solution as a dopant, and the thermoelectric performance of two-dimensional transition metal disulfide nanosheets is improved through electronic structure regulation. Since the S atoms on the surface of the disulfide are negatively charged, and the aluminum ions are positively charged, the positive and negative attract each other, so that the aluminum ions bind adjacent different disulfides together, thereby having better electrical properties. Even if a small amount of aluminum chloride solution is added, the electrical conductivity and the Seebeck coefficient can be simultaneously improved, the thermoelectric power is increased by 14 times compared with before modification, and better stability in temperature and relative humidity is maintained. Then, the n / p type thermoelectric material after modification is used to form a flexible thermoelectric device with a self-healing function. By using human heat, the device achieves an output voltage of about 15 mV, which is obviously improved compared with existing two-dimensional transition metal sulfide-based thermoelectric wearable devices, and is an important step for realizing practical application.

Description

Technical Field

[0001] This invention relates to the field of wearable thermoelectric device technology, and in particular to a wearable thermoelectric generator with self-healing function and its preparation method. Background Technology

[0002] In recent years, various wearable electronic devices, such as smartwatches, smart glasses, and smart clothing, have become common products in daily life, and lightweight, flexible power supply systems are key to ensuring their normal operation. Self-powered systems, with their environmentally friendly characteristics and ability to continuously convert energy, make full use of the thermal energy from the human body and the environment.

[0003] Thermoelectric materials can convert heat energy into electrical energy, and their properties are defined by the infinite dimension ZT: ZT = (α 2 σT) / κ, where α is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the thermal conductivity. Thermoelectric materials for converting heat energy into electrical energy in the human body must meet the requirements of being close to room temperature and having flexibility. Currently, the most commonly used thermoelectric materials are bismuth telluride-based materials and organic conductive polymers, but the former is rigid and toxic, while the latter has relatively low thermoelectric performance.

[0004] Two-dimensional transition metal sulfides are considered ideal room-temperature thermoelectric materials due to their high carrier mobility and good flexibility resulting from the quantum confinement effect. Representative two-dimensional transition metal sulfide materials, MoS2 and TiS2, have achieved thermoelectric powers of 8.5 and 3.7 mW / mK, respectively. 2 It can be compared with bismuth telluride-based materials.

[0005] Currently, the main methods for controlling the electronic structure of two-dimensional transition metal sulfides to improve thermoelectric properties include defect engineering, alloying, and surface modification. Among these, surface modification has the advantages of mild processing conditions, strong controllability, and ease of large-scale fabrication. For example, Wang Yifeng et al., in patent authorization number CN105226180B, used a method of mixing MoS2 powder and TiS2 powder prepared by ball milling to improve their final thermoelectric properties. However, this method is only suitable for preparing thermoelectric materials and is difficult to integrate with flexible wearable processes. Summary of the Invention

[0006] This invention provides a wearable thermoelectric generator with self-healing function and its preparation method, the purpose of which is to solve the above-mentioned problems existing in the background art.

[0007] To achieve the above objectives, embodiments of the present invention provide a wearable thermoelectric generator with self-healing capabilities and its fabrication method. This method uses aluminum chloride slurry as a dopant and improves the thermoelectric properties of MoS2 and TiS2 nanosheets through electronic structure modulation. The mechanism utilizes the negatively charged sulfur atoms on the surface of MoS2 and TiS2 nanosheets, while aluminum ions in Lewis acid solutions (such as aluminum chloride) are positively charged. The attraction between positive and negative charges allows aluminum ions to bind adjacent MoS2 or TiS2 nanosheets together, resulting in better electrical performance. Even with the addition of a small amount of AlCl3 slurry, both conductivity and Seebeck coefficient are simultaneously improved, the thermoelectric power is increased by 14 times compared to before modification, and better stability is maintained at temperature and relative humidity. Furthermore, the modified TiS2 nanosheets are used as n-type thermoelectric materials, and the modified MoS2 nanosheets are used as p-type thermoelectric materials to fabricate flexible thermoelectric devices with self-healing properties. By utilizing human body heat, the device achieves an output voltage of approximately 15mV, which is a significant improvement over existing two-dimensional transition metal sulfide-based thermoelectric wearable devices, marking an important step towards their practical application.

[0008] An embodiment of the present invention provides a wearable thermoelectric generator with self-healing function, including a substrate and a p / n type thermoelectric unit composited on the substrate; the p / n type thermoelectric unit includes one or more sets of p / n type thermoelectric thin film materials connected in series and parallel;

[0009] The multiple sets of p / n type thermoelectric thin film materials connected in series and parallel have gaps between them; p-type thermoelectric thin film materials and n-type thermoelectric thin film materials are arranged alternately; p-type thermoelectric thin film materials and n-type thermoelectric thin film materials are connected to each other by conductive materials.

[0010] The substrate includes a flexible substrate film layer; the substrate is made of at least one of polydimethylsiloxane, styrene-based thermoplastic elastomer, and polyimide;

[0011] The p / n type thermoelectric unit is a thin film material made of two-dimensional transition metal dichalcogenide nanosheets doped with Lewis acid solution.

[0012] The two-dimensional transition metal dichalcogenide nanosheets include at least one of MoS2, TiS2, WS2, MoSe2, and WSe2;

[0013] The Lewis acid solution includes at least one of aluminum trichloride, boron trifluoride, sulfur trioxide, and ferric bromide.

[0014] Preferably, the p / n type thermoelectric unit is a thin film material made of two-dimensional TiS2 nanosheets and MoS2 nanosheets doped with Lewis acid solution.

[0015] Preferably, the p / n type thermoelectric unit is a thin film material made of two-dimensional TiS2 nanosheets and MoS2 nanosheets doped with AlCl3 solution.

[0016] Preferably, the concentration of the Lewis acid solution is 1 mmol / L.

[0017] Preferably, the dimensions of the p / n type thermoelectric unit are: 2cm in length and 0.5cm in width; the spacing between the p / n type thermoelectric units is 0.1 to 1cm.

[0018] Preferably, the doping process employs either lithium intercalation stripping or ultrasonic dispersion.

[0019] Preferably, the nanosheet has a diameter of 1.5 cm.

[0020] Preferably, the conductive material includes at least one of silver paste, silver wire, liquid metal, graphene, carbon nanotubes, and copper nanowires.

[0021] Preferably, the thickness of the substrate is several micrometers.

[0022] Based on a general inventive concept, embodiments of the present invention provide a method for preparing the above-mentioned wearable thermoelectric generator with self-healing function, comprising the following steps:

[0023] S1: Mold preparation: Based on the size and spacing of the thermoelectric units, the flexible substrate is machined into the required shape and size through mechanical processing;

[0024] S2: Preparation of flexible substrate: Mix the substrate and curing agent thoroughly at a mass ratio of 10:1, pour into the mold in step S1, cure at 65°C for 4 hours, and cut into appropriate sizes after cooling;

[0025] S3: Preparation of p / n type thermoelectric thin film material: A two-dimensional transition metal disulfide nanosheet dispersion was prepared by lithium intercalation exfoliation method, and then the two-dimensional transition metal disulfide nanosheet dispersion was doped with Lewis acid solution to prepare p / n type thermoelectric thin film material.

[0026] S4: The p / n type thermoelectric thin film material is attached to a flexible substrate and arranged in a cross pattern. Then, it is connected to each other with a conductive material to form an electrode, so that each thermoelectric unit forms a series-parallel structure.

[0027] Preferably, step S3 specifically includes the following process:

[0028] Step 1: Prepare TiS2 nanosheet dispersion using the lithium intercalation exfoliation method:

[0029] TiS2 powder, n-butyllithium solution, and n-hexane solution were continuously stirred under nitrogen atmosphere to ensure thorough mixing, thereby completing the lithium intercalation process to synthesize Li. x TiS2; the precipitate in the above solution was obtained by filtration and washed several times with n-hexane to remove excess n-butyllithium. The precipitate was then placed in deionized water for exfoliation, combined with ultrasonic-assisted exfoliation at a power of 200W for 5 minutes. After exfoliation, the resulting solution was centrifuged several times at 10,000 rpm to remove Li atoms and unexfoliated material, thus obtaining a high-quality ultrathin TiS2 nanosheet dispersion.

[0030] Step 2: Prepare MoS2 nanosheet dispersion using the lithium intercalation exfoliation method:

[0031] (1) MoS2 powder and n-butyllithium solution were added to n-hexane and stirred at room temperature under nitrogen atmosphere in a glove box to ensure thorough mixing;

[0032] (2) Place the obtained mixed dispersion in a centrifuge and centrifuge at 10,000 rpm for 10 minutes. Collect the precipitate after centrifugation. Then disperse the precipitate in n-hexane and centrifuge at 10,000 rpm for 10 minutes and collect the precipitate. Repeat this operation 3 times to remove excess n-butyllithium.

[0033] (3) The washed precipitate was added to deionized water and placed in a cell disruptor for ultrasonic exfoliation at room temperature and 600W power for 60 minutes to obtain a MoS2 nanosheet dispersion.

[0034] (4) Place the obtained MoS2 nanosheet dispersion back into the centrifuge and centrifuge at 10,000 rpm for 5 minutes to remove the unstripped MoS2 precipitate. Repeat the operation 3 times to obtain a well dispersed MoS2 nanosheet dispersion.

[0035] Step 3: Preparation of thermoelectric thin films assembled from AlCl3-doped TiS2 nanosheets and AlCl3-doped MoS2 nanosheets:

[0036] A dispersion of TiS2 or MoS2 nanosheets and a certain volume of AlCl3 solution are simultaneously and uniformly added to a vacuum filtration device (the two solutions should not be mixed beforehand, otherwise it will cause the nanosheets to agglomerate) and then vacuum filtered. After filtration, the resulting film is dried under vacuum at room temperature to remove residual moisture, thus completing the preparation process.

[0037] Preferably, step S4 specifically includes the following process:

[0038] AlCl3-modified TiS2 nanosheet assembled films and modified MoS2 nanosheet assembled films were attached face-to-face to a PDMS substrate. After drying, the PDMS films were peeled off, revealing that the thermoelectric film had been transferred to the PDMS. Then, arrays of AlCl3-modified TiS2 nanosheet assembled films and modified MoS2 nanosheet assembled films were attached to the PDMS substrate, arranged in a crisscross pattern, and interconnected with silver paste and silver wires.

[0039] The above-described solution of the present invention has the following beneficial effects:

[0040] 1. This invention utilizes a surface modification method to regulate the electronic structure of TiS2 nanosheets using a small amount of AlCl3 solution. By adjusting the amount of AlCl3 solution, both conductivity and Seebeck coefficient can be simultaneously improved. This phenomenon overcomes the problem of the mutual constraint between conductivity and Seebeck coefficient in traditional thermoelectric materials.

[0041] 2. This invention improves the environmental adaptability and stability of materials. Through surface modification, TiS2 and MoS2 films exhibit significant performance stability under different temperature and relative humidity conditions, which significantly expands the application range of these materials in complex environments.

[0042] 3. The flexible thermoelectric device designed and fabricated in this invention exhibits self-healing properties. After the device breaks under tension, it can recover to its original shape and regenerate its thermoelectric voltage once the external force is removed. Furthermore, after 1000 repeated bending cycles, the power output only decreases by about 12%, demonstrating excellent mechanical stability and meeting the flexibility and durability requirements of wearable devices.

[0043] 4. Unlike traditional doping and defect engineering techniques, this invention uses surface modification technology, which has mild reaction conditions, strong controllability, and is suitable for large-scale preparation, providing an economical and efficient solution for the practical application of high-performance thermoelectric materials. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the preparation process of two-dimensional transition metal dichalcogenide nanosheets according to an embodiment of the present invention;

[0046] Figure 2 These are scanning electron microscope images of the two-dimensional TiS2 nanosheets prepared according to embodiments of the present invention;

[0047] Figure 3 These are scanning electron microscope images of the two-dimensional MoS2 nanosheets prepared according to embodiments of the present invention;

[0048] Figure 4 This is a schematic diagram of the process for preparing a two-dimensional transition metal dichalcogenide flexible thermoelectric thin film according to an embodiment of the present invention;

[0049] Figure 5 This is a thermoelectric performance diagram of the n-type two-dimensional TiS2 nanosheet thermoelectric thin film prepared in the embodiments of the present invention. From left to right, the diagram shows the conductivity, Seebeck coefficient and power factor for different AlCl3 doping amounts.

[0050] Figure 6 This is a thermoelectric performance diagram of the p-type two-dimensional MoS2 nanosheet thermoelectric thin film prepared in the embodiments of the present invention. From left to right, the diagram shows the conductivity, Seebeck coefficient and power factor for different AlCl3 doping amounts.

[0051] Figure 7 This is a schematic diagram illustrating the transfer of a two-dimensional transition metal dichalcogenide flexible thermoelectric thin film prepared by vacuum filtration to a flexible stretchable PDMS substrate according to an embodiment of the present invention.

[0052] Figure 8 This is a photograph of a thermoelectric power generation device according to an embodiment of the present invention, which is composed of a thermoelectric thin film of n-type two-dimensional TiS2 nanosheet and a thermoelectric thin film of p-type two-dimensional MoS2 nanosheet connected in series.

[0053] Figure 9 This invention provides a thermoelectric power generation device composed of multiple n-type two-dimensional TiS2 nanosheet thermoelectric films and multiple p-type two-dimensional MoS2 nanosheet thermoelectric films connected in series.

[0054] Figure 10 This is a diagram illustrating the stretchable and self-healing properties of the thermoelectric power generation device according to an embodiment of the present invention. Detailed Implementation

[0055] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0056] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0057] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0058] This invention addresses existing problems by providing a wearable thermoelectric generator with self-healing capabilities, comprising a substrate and a p / n type thermoelectric unit composited on the substrate; the p / n type thermoelectric unit comprises one or more sets of p / n type thermoelectric thin film materials connected in series and parallel.

[0059] The multiple sets of p / n type thermoelectric thin film materials connected in series and parallel have gaps between them; p-type thermoelectric thin film materials and n-type thermoelectric thin film materials are arranged alternately at intervals; p-type thermoelectric thin film materials and n-type thermoelectric thin film materials are connected to each other by conductive materials.

[0060] The substrate includes a flexible substrate film layer; the substrate is made of at least one of polydimethylsiloxane, styrene-based thermoplastic elastomer, and polyimide;

[0061] The p / n type thermoelectric unit is a thin film material made of two-dimensional transition metal dichalcogenide nanosheets doped with Lewis acid solution.

[0062] The two-dimensional transition metal dichalcogenide nanosheets include at least one of MoS2, TiS2, WS2, MoSe2, and WSe2;

[0063] The Lewis acid solution includes at least one of aluminum trichloride, boron trifluoride, sulfur trioxide, and ferric bromide.

[0064] Preferably, the p / n type thermoelectric unit is a thin film material made of two-dimensional TiS2 nanosheets and MoS2 nanosheets doped with Lewis acid solution.

[0065] Preferably, the p / n type thermoelectric unit is a thin film material made of two-dimensional TiS2 nanosheets and MoS2 nanosheets doped with AlCl3 solution.

[0066] Preferably, the concentration of the Lewis acid solution is 1 mmol / L.

[0067] Preferably, the dimensions of the p / n type thermoelectric unit are: 2cm in length and 0.5cm in width; the spacing between the p / n type thermoelectric units is 0.1 to 1cm.

[0068] Preferably, the doping process employs either lithium intercalation stripping or ultrasonic dispersion.

[0069] Preferably, the nanosheet has a diameter of 1.5 cm.

[0070] Preferably, the conductive material includes at least one of silver paste, silver wire, liquid metal, graphene, carbon nanotubes, and copper nanowires.

[0071] Preferably, the thickness of the substrate is several micrometers.

[0072] Based on a general inventive concept, embodiments of the present invention provide a method for preparing the above-mentioned wearable thermoelectric generator with self-healing function, comprising the following steps:

[0073] S1: Mold preparation: Based on the size and spacing of the thermoelectric units, the flexible substrate is machined into the required shape and size through mechanical processing;

[0074] S2: Preparation of flexible substrate: Mix the substrate and curing agent thoroughly at a mass ratio of 10:1, pour the mixture into the mold in step S1, cure at 65°C for 4 hours, and cut into appropriate sizes after cooling.

[0075] S3: Preparation of p / n type thermoelectric thin film material: A two-dimensional transition metal disulfide nanosheet dispersion was prepared by lithium intercalation exfoliation method, and then the two-dimensional transition metal disulfide nanosheet dispersion was doped with Lewis acid solution to prepare p / n type thermoelectric thin film material.

[0076] S4: The p / n type thermoelectric thin film material is attached to a flexible substrate and arranged in a cross pattern. Then, it is connected to each other with a conductive material to form an electrode, so that each thermoelectric unit forms a series-parallel structure.

[0077] Preferably, step S3 specifically includes the following process:

[0078] Step 1: Prepare TiS2 nanosheet dispersion using the lithium intercalation exfoliation method:

[0079] TiS2 powder, n-butyllithium solution, and n-hexane solution were continuously stirred under nitrogen atmosphere to ensure thorough mixing, thereby completing the lithium intercalation process to synthesize Li. x TiS2; the precipitate in the above solution was obtained by filtration and washed several times with n-hexane to remove excess n-butyllithium. The precipitate was then placed in deionized water for exfoliation, combined with ultrasonic-assisted exfoliation at a power of 200W for 5 minutes. After exfoliation, the resulting solution was centrifuged several times at 10,000 rpm to remove Li atoms and unexfoliated material, thus obtaining a high-quality ultrathin TiS2 nanosheet dispersion.

[0080] Step 2: Prepare MoS2 nanosheet dispersion using the lithium intercalation exfoliation method:

[0081] (1) MoS2 powder and n-butyllithium solution were added to n-hexane and stirred at room temperature under nitrogen atmosphere in a glove box to ensure thorough mixing;

[0082] (2) Place the obtained mixed dispersion in a centrifuge and centrifuge at 10,000 rpm for 10 minutes. Collect the precipitate after centrifugation. Then disperse the precipitate in n-hexane and centrifuge at 10,000 rpm for 10 minutes and collect the precipitate. Repeat this operation 3 times to remove excess n-butyllithium.

[0083] (3) The washed precipitate was added to deionized water and placed in a cell disruptor for ultrasonic exfoliation at room temperature and 600W power for 60 minutes to obtain a MoS2 nanosheet dispersion.

[0084] (4) Place the obtained MoS2 nanosheet dispersion back into the centrifuge and centrifuge at 10,000 rpm for 5 minutes to remove the unstripped MoS2 precipitate. Repeat the operation 3 times to obtain a well dispersed MoS2 nanosheet dispersion.

[0085] Step 3: Preparation of thermoelectric thin films assembled from AlCl3-doped TiS2 nanosheets and AlCl3-doped MoS2 nanosheets:

[0086] A dispersion of TiS2 or MoS2 nanosheets and a certain volume of AlCl3 solution are simultaneously and uniformly added to a vacuum filtration device (the two solutions should not be mixed beforehand, otherwise it will cause the nanosheets to agglomerate) and then vacuum filtered. After filtration, the resulting film is dried under vacuum at room temperature to remove residual moisture, thus completing the preparation process.

[0087] Preferably, step S4 specifically includes the following process:

[0088] AlCl3-modified TiS2 nanosheet assembled films and modified MoS2 nanosheet assembled films were attached face-to-face to a PDMS substrate. After drying, the PDMS films were peeled off, revealing that the thermoelectric film had been transferred to the PDMS. Then, arrays of AlCl3-modified TiS2 nanosheet assembled films and modified MoS2 nanosheet assembled films were attached to the PDMS substrate, arranged in a crisscross pattern, and interconnected with silver paste and silver wires.

[0089] The following is a detailed explanation through specific examples. Corning 184 curing agent is used in this example.

[0090] Example

[0091] A method for preparing a wearable thermoelectric generator with self-healing function includes the following steps:

[0092] S1: Mold preparation: Based on the size and spacing of the thermoelectric units, the flexible substrate is machined into the required shape and size through mechanical processing;

[0093] S2: Preparation of flexible substrate: Mix PDMS and curing agent thoroughly at a mass ratio of 10:1, pour into the mold in step S1, cure at 65°C for 4 hours, and cut into appropriate size after cooling;

[0094] Preparation of S3:p / n type thermoelectric thin film material: Two-dimensional transition metal dichalcogenide nanosheet dispersion was prepared by lithium intercalation exfoliation method;

[0095] S4: The p / n type thermoelectric thin film material is attached to a flexible substrate and arranged in a cross pattern. Then, it is connected to each other with a conductive material to form an electrode, so that each thermoelectric unit forms a series-parallel structure.

[0096] Step S3 specifically includes the following process:

[0097] Step 1: Prepare TiS2 nanosheet dispersion using the lithium intercalation exfoliation method. (See schematic diagram below.) Figure 1 :

[0098] 0.2 g TiS2 powder, 2 mL n-butyllithium solution, and 8 mL n-hexane solution were continuously stirred under nitrogen atmosphere for 18 hours to ensure thorough mixing, thus completing the lithium intercalation process to synthesize Li. x TiS2. The precipitate in the above solution was obtained by filtration and washed several times with n-hexane to remove excess n-butyllithium. The precipitate was then placed in deionized water for exfoliation using ultrasonic-assisted exfoliation at a power of 200 W for 5 minutes. After exfoliation, the resulting solution was centrifuged several times at 10,000 rpm to remove Li atoms and any unexfoliated material, yielding a high-quality ultrathin TiS2 nanosheet dispersion. Optical images of the TiS2 nanosheets are shown below. Figure 2 .

[0099] Step 2: Prepare MoS2 nanosheet dispersion using the lithium intercalation exfoliation method. See the flowchart below. Figure 1 :

[0100] (1) 0.6 g MoS2 powder and 6 mL n-butyllithium solution were added to 24 mL n-hexane and stirred at room temperature for 48 hours under nitrogen atmosphere in a glove box;

[0101] (2) Place the obtained mixed dispersion in a centrifuge and centrifuge at 10,000 rpm for 10 minutes. Collect the precipitate after centrifugation. Then disperse the precipitate in n-hexane and centrifuge at 10,000 rpm for 10 minutes and collect the precipitate. Repeat this operation 3 times to remove excess n-butyllithium.

[0102] (3) Add the washed precipitate to 400 mL of deionized water and place it in a cell disruptor for ultrasonic exfoliation at room temperature and 600 W power for 60 minutes to obtain a MoS2 nanosheet dispersion.

[0103] (4) Place the obtained dispersion back into a centrifuge and centrifuge at 10,000 rpm for 5 minutes to remove any unremoved MoS2 precipitate. Repeat this process 3 times to obtain a well-dispersed MoS2 nanosheet dispersion. Optical photographs of the MoS2 nanosheets are shown below. Figure 3 .

[0104] Step 3: Preparation of thermoelectric thin films assembled from AlCl3-doped TiS2 nanosheets and AlCl3-doped MoS2 nanosheets. (See schematic diagram below.) Figure 4 :

[0105] 5 mL of TiS2 or MoS2 nanosheet dispersion and a certain volume of 1 mmol / L AlCl3 solution were simultaneously and uniformly added to a vacuum filtration apparatus (the two solutions should not be mixed beforehand, otherwise it will cause nanosheet agglomeration) for vacuum filtration. After completion, the resulting film was vacuum dried at room temperature to remove residual moisture, thus completing the preparation. Changing the AlCl3 solution can yield thermoelectric properties of thermoelectric films with different doping concentrations; specific properties can be found in [link to documentation]. Figure 5 and Figure 6 .

[0106] Step S4 specifically includes the following process:

[0107] The thermoelectric thin film was transferred to a stretchable PDMS substrate, and the steps are as follows (see flowchart). Figure 7 :

[0108] Fabrication of flexible PDMS substrate: Mix PDMS and curing agent thoroughly at a mass ratio of 10:1, pour into a specific mold, cure at 65℃ for 4 hours, and cut into appropriate sizes after cooling.

[0109] AlCl3-modified TiS2 nanosheet assembled films and modified MoS2 nanosheet assembled films were attached face-to-face to a PDMS substrate. After drying, the PDMS films were peeled off, and the thermoelectric film was transferred onto the PDMS.

[0110] AlCl3-modified TiS2 nanosheets and MoS2-modified nanosheets, each measuring 0.5 × 2 cm, were respectively attached to a PDMS substrate and arranged in a crisscross pattern, then interconnected with silver paste and silver wires. The films were encapsulated with PDMS to isolate them from air, and half of each film was covered with thermal insulation tape, thus completing the fabrication of the thermoelectric wristband. A series of p / n-type thermoelectric thin film materials are shown in the figure below. Figure 8 Multiple sets of p / n type thermoelectric thin film materials connected in series are shown in the figure. Figure 9 .

[0111] The self-healing performance of the aforementioned thermoelectric thin film material was tested. After the device fractured under tension, it recovered to its original shape and regenerated its thermoelectric voltage upon removal of the external force. Furthermore, after 1000 repeated bending cycles, the power output only decreased by approximately 12%, demonstrating excellent mechanical stability and meeting the flexibility and durability requirements of wearable devices. Its stretchable and self-healing properties are demonstrated as follows: Figure 10 As shown.

[0112] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A wearable thermoelectric generator with self-healing function, characterized in that, It includes a substrate and a p / n type thermoelectric unit composited on the substrate; the p / n type thermoelectric unit includes one or more sets of p / n type thermoelectric thin film materials connected in series and parallel. The multiple sets of p / n type thermoelectric thin film materials connected in series and parallel have gaps between them; p-type thermoelectric thin film materials and n-type thermoelectric thin film materials are arranged alternately at intervals; p-type thermoelectric thin film materials and n-type thermoelectric thin film materials are connected to each other by conductive materials. The substrate includes a flexible substrate film layer; the substrate is made of at least one of polydimethylsiloxane, styrene-based thermoplastic elastomer, and polyimide; The p / n type thermoelectric unit is a thin film material made of two-dimensional transition metal dichalcogenide nanosheets doped with Lewis acid solution. The two-dimensional transition metal dichalcogenide nanosheets include at least one of MoS2, TiS2, WS2, MoSe2, and WSe2; The Lewis acid solution includes at least one of aluminum trichloride, boron trifluoride, sulfur trioxide, and ferric bromide; The p / n type thermoelectric thin film material was prepared by: preparing a two-dimensional transition metal disulfide nanosheet dispersion using a lithium intercalation exfoliation method, and then doping the two-dimensional transition metal disulfide nanosheet dispersion with a Lewis acid solution to prepare the p / n type thermoelectric thin film material. The specific process for preparing the p / n type thermoelectric thin film material includes the following steps: Step 1: Preparation of TiS2 nanosheet dispersion: TiS2 powder, n-butyllithium solution, and n-hexane solution were continuously stirred under nitrogen atmosphere until fully mixed to synthesize Li. x TiS2; the precipitate in the above solution was filtered and washed several times with n-hexane to remove excess n-butyllithium. The precipitate was then placed in deionized water and subjected to an ultrasonic-assisted exfoliation process with an ultrasonic power of 200 W for 5 minutes. After the exfoliation was completed, the resulting solution was centrifuged several times at 10,000 rpm to obtain a TiS2 nanosheet dispersion. Step 2: Preparation of MoS2 nanosheet dispersion: MoS2 powder and n-butyllithium solution were added to n-hexane and stirred at room temperature under nitrogen atmosphere in a glove box until fully mixed. The resulting dispersion was centrifuged at 10,000 rpm for 10 minutes and the precipitate was collected. The precipitate was then dispersed in n-hexane and centrifuged at 10,000 rpm for 10 minutes and the precipitate was collected. This operation was repeated 3 times. The washed precipitate was added to deionized water and ultrasonically exfoliated at 600 W at room temperature for 60 minutes in a cell disruptor. It was then centrifuged again at 10,000 rpm for 5 minutes to remove the unexfoliated MoS2 precipitate. This operation was repeated 3 times to obtain a MoS2 nanosheet dispersion. Step 3: Preparation of AlCl3-doped TiS2 nanosheets and AlCl3-doped MoS2 nanosheets for assembling thermoelectric thin films: TiS2 or MoS2 nanosheet dispersion and AlCl3 solution are simultaneously and uniformly added to a vacuum filtration device for vacuum filtration. After completion, the resulting film is vacuum dried at room temperature.

2. The wearable thermoelectric generator with self-healing function according to claim 1, characterized in that, The p / n type thermoelectric unit is made of thin film material formed by doping two-dimensional TiS2 nanosheets and MoS2 nanosheets with Lewis acid solution.

3. The wearable thermoelectric generator with self-healing function according to claim 2, characterized in that, The p / n type thermoelectric unit is made of thin film material formed by doping two-dimensional TiS2 nanosheets and MoS2 nanosheets with AlCl3 solution.

4. The wearable thermoelectric generator with self-healing function according to claim 3, characterized in that, The dimensions of the p / n type thermoelectric unit are: 2 cm in length and 0.5 cm in width; the spacing between the p / n type thermoelectric units is 0.1~1 cm.

5. The wearable thermoelectric generator with self-healing function according to claim 4, characterized in that, The concentration of the Lewis acid solution is 1 mmol / L.

6. The wearable thermoelectric generator with self-healing function according to claim 1, characterized in that, The doping process employs either lithium intercalation stripping or ultrasonic dispersion.

7. The wearable thermoelectric generator with self-healing function according to claim 1, characterized in that, The nanosheets have a diameter of 1.5 cm.

8. The wearable thermoelectric generator with self-healing function according to claim 1, characterized in that, The conductive material includes at least one of silver paste, silver wire, liquid metal, graphene, carbon nanotubes, and copper nanowires.

9. A method for preparing a wearable thermoelectric generator with self-healing function as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1: Mold preparation: Based on the size and spacing of the thermoelectric units, the flexible substrate is machined into the required shape and size through mechanical processing; S2: Preparation of flexible substrate: Mix the substrate and curing agent thoroughly at a mass ratio of 10:1, pour into the mold in step S1, cure at 65 ℃ for 4 hours, and cut into appropriate size after cooling; S3: Preparation of p / n type thermoelectric thin film material: A two-dimensional transition metal disulfide nanosheet dispersion was prepared by lithium intercalation exfoliation method, and then the two-dimensional transition metal disulfide nanosheet dispersion was doped with Lewis acid solution to prepare p / n type thermoelectric thin film material. S4: The p / n type thermoelectric thin film material is attached to a flexible substrate and arranged in a cross pattern. Then, it is connected to each other with a conductive material to form an electrode, so that each thermoelectric unit forms a series-parallel structure.

10. The preparation method according to claim 9, characterized in that, Step S3 includes the following steps: Step 1: Preparation of TiS2 nanosheet dispersion: TiS2 powder, n-butyllithium solution, and n-hexane solution were continuously stirred under nitrogen atmosphere until fully mixed to synthesize Li. x TiS2; the precipitate in the above solution was filtered and washed several times with n-hexane to remove excess n-butyllithium. The precipitate was then placed in deionized water and subjected to an ultrasonic-assisted exfoliation process with an ultrasonic power of 200 W for 5 minutes. After the exfoliation was completed, the resulting solution was centrifuged several times at 10,000 rpm to obtain a TiS2 nanosheet dispersion. Step 2: Preparation of MoS2 nanosheet dispersion: MoS2 powder and n-butyllithium solution were added to n-hexane and stirred at room temperature under nitrogen atmosphere in a glove box until fully mixed. The resulting dispersion was centrifuged at 10,000 rpm for 10 minutes and the precipitate was collected. The precipitate was then dispersed in n-hexane and centrifuged at 10,000 rpm for 10 minutes and the precipitate was collected. This operation was repeated 3 times. The washed precipitate was added to deionized water and ultrasonically exfoliated at 600 W at room temperature for 60 minutes in a cell disruptor. It was then centrifuged again at 10,000 rpm for 5 minutes to remove the unexfoliated MoS2 precipitate. This operation was repeated 3 times to obtain a MoS2 nanosheet dispersion. Step 3: Preparation of AlCl3-doped TiS2 nanosheets and AlCl3-doped MoS2 nanosheets for assembling thermoelectric thin films: TiS2 or MoS2 nanosheet dispersion and AlCl3 solution are simultaneously and uniformly added to a vacuum filtration device for vacuum filtration. After completion, the resulting film is vacuum dried at room temperature.

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