CN114539574B - Preparation method and application of piezoelectric-triboelectric coupling sensing material - Google Patents

Abstract

The invention discloses a preparation method and application of a piezoelectric-triboelectric coupling induction material. The preparation method includes the following steps: S1: dissolving hydroxypropyl cellulose, chitosan, and carbon nanotubes in an acidic solution to prepare Obtain the hydroxypropyl cellulose/chitosan/carbon nanotube solution; S2: cast the hydroxypropyl cellulose/chitosan/carbon nanotube solution on the polytetrafluoroethylene substrate and dry it to obtain piezoelectric-friction electrically coupled sensing material. The sensing material of the present invention adopts HPC, CTS and CNT to prepare the positive electrode of the piezoelectric-triboelectric coupling sensing material and a thin film with piezoelectric performance by casting method, which has excellent mechanical properties and signal conversion performance.

Description

Preparation method and application of piezoelectric-triboelectric coupling sensing material

technical field

The invention relates to a piezoelectric-triboelectric coupling induction material, in particular to a preparation method and application of the piezoelectric-triboelectric coupling induction material.

Background technique

At present, the increasingly intensified energy shortage problem and the huge power consumption caused by people's high dependence on smart electronic products, the conflict between the two has promoted the research of various sustainable alternative clean energy sources, such as wind energy , geothermal energy, biological energy, mechanical energy, nuclear energy, etc., have received widespread attention because of their green environmental protection and recyclable characteristics. Among them, mechanical energy has great potential because it has a wide range of divisions in the environment, has various forms, is almost not affected by the external environment, and is energy-dense and easy to collect. In recent years, the research on the collection of mechanical energy has mainly focused on several mechanisms such as piezoelectricity, triboelectricity, piezoelectricity and piezoelectric-triboelectric coupling, especially the piezoelectric-triboelectric coupling flexible sensor energy storage device, due to its With unique advantages such as small mass, high flexibility, high performance, and high sensitivity, it has a wide range of research applications in various fields. With the development of modern technology and national defense technology, the size requirements of electronic devices are getting smaller and smaller, the performance requirements are getting higher and higher, and the concealment is getting higher and higher. To meet this demand, at present, in real life, tiny electronic products and devices are mainly powered by chemical batteries, because chemical batteries have the advantages of stable output energy and the like. But in some special environments, chemical batteries have some unavoidable defects. For example, for tiny electronic devices, most of them are used for a long time, but because of the high cost of recycling, they will be discarded. Therefore, the use of chemical batteries will cause huge pollution to the environment, and due to volume limitations, chemical batteries cannot meet the needs of tiny electronic devices. The existence of these defects makes chemical batteries unable to meet the energy requirements of tiny detection electronics.

The piezoelectric-triboelectric coupled nanogenerator (PTENG) combines the coupling effect of triboelectricity and electrostatic induction with the piezoelectric effect to convert the mechanical energy in the environment into an electrical signal output. It has a simple structure, low cost, With the characteristics of high integration, excellent performance, and various types of preparation materials, it can be widely used in mechanical energy collection and self-powered sensors. However, the piezoelectric-triboelectric coupled nanogenerators in the prior art still have certain problems because of their low electric output amplitude and low force/electricity conversion efficiency.

Contents of the invention

In view of the above problems, the present invention provides a preparation method and application of a piezoelectric-triboelectric coupling induction material. The material adopts HPC, CTS and CNT to prepare the positive electrode of the piezoelectric-triboelectric coupling induction material by casting method and has both Thin films with piezoelectric properties, excellent mechanical properties and signal conversion properties.

In order to achieve the above object, the present invention provides a method for preparing a piezoelectric-triboelectric coupling induction material, which is characterized in that it includes the following steps:

S1: Dissolving hydroxypropyl cellulose, chitosan, and carbon nanotubes in an acidic solution to prepare a hydroxypropyl cellulose/chitosan/carbon nanotube solution;

S2: The hydroxypropyl cellulose/chitosan/carbon nanotube solution is cast on a polytetrafluoroethylene substrate and dried to obtain a piezoelectric-triboelectric coupling sensing material.

Hydroxypropyl cellulose (HPC) is a potential self-assembled cellulose nanomaterial, which has the advantages of low cost, renewable, easy mass production, environmental protection, and non-toxic; chitosan (CTS) is a natural polysaccharide chitin Partially acetylated products have biodegradability, biocompatibility, non-toxic and antibacterial properties, and are widely used in food additives, textiles, artificial tissue materials, biomedicine and many other fields; carbon nanotubes (CNTs) as a Dimensional nanomaterials are light in weight, perfectly connected in a hexagonal structure, and have excellent mechanical, electrical, and chemical properties. In recent years, with the deepening of research on carbon nanotubes and nanomaterials, their broad application prospects have also been continuously revealed. Both HPC and CTS are highly biocompatible polymer materials with degradability, and HPC itself also has certain piezoelectric properties. Therefore, using HPC and CTS as raw materials, adding an appropriate amount of CNT coordinates and enhances the mechanical and electrical properties. , can be combined to obtain a film with piezoelectric properties. Its piezoelectric principle is: HPC is a crystal with an asymmetric structure, so the nano-microcrystalline cellulose in the film can be arranged in an orderly manner by applying voltage polarization. Such a thin film deforms under the action of mechanical force to cause the relative displacement of charged particles, so that the total electric moment of the crystal changes to produce piezoelectric effect. Because HPC is positively charged and CTS is also positively charged when the amino group is protonated under acidic conditions, the thin film made by HPC/CTS/CNT solution casting can also serve as the positive electrode of the generator.

Specifically, in step S1, the preparation method of the hydroxypropyl cellulose/chitosan/carbon nanotube solution is: dissolving chitosan in an acidic solution with an acid concentration of 0.5-1.5%, and then dissolving the Add hydroxypropyl cellulose therein and mix evenly, add carbon nanotubes at last, mix evenly, the concentration of chitosan in the described hydroxypropylcellulose/chitosan/carbon nanotube solution is 2～5%, hydroxypropyl cellulose The base cellulose concentration is 9-12%, and the carbon nanotube concentration is 0.5-1%.

In the above technical solution, the acidic solution is glacial acetic acid, carbonic acid, etc., and the purpose is to make the amino group of CTS positively charged by protonation under acidic conditions, so as to constitute a part of the whole triboelectrification.

Preferably, the interval between each addition of the hydroxypropyl cellulose is 15-30 minutes, and ultrasonic treatment is performed at a temperature lower than 30°C.

Because HPC will precipitate at a temperature above 35°C, ultrasonic treatment should be performed at a low temperature below 30°C.

Specifically, after the hydroxypropyl cellulose is added and mixed uniformly, the solution is left to stand at 0-10°C for 3-6 hours, and after the carbon nanotubes are added and mixed uniformly, the solution is left to stand at room temperature for 24 hours. ~30h, and then carry out degassing treatment.

In the above technical solution, the function of degassing is to remove air bubbles. Centrifugal degassing is preferred, and the treatment conditions are 8-12kpm, 15-30min.

Specifically, in step S2, the hydroxypropyl cellulose/chitosan/carbon nanotube solution is cast on the polytetrafluoroethylene substrate, the surface of the solution after casting should be parallel to the substrate, and then lose water until the Stretching into a film, and then standing at room temperature for 1 to 2 hours, then removing the film and performing polarization to obtain a piezoelectric-triboelectric coupling sensing material film.

In the above technical solution, drying is adopted for dehydration, the drying temperature is 50-55° C., and the dehydration time is 6-12 hours.

In the piezoelectric-triboelectric coupling sensing material, the relative orientation of each crystal grain is completely disordered, which makes the orientation of the electric domain also completely disordered. Therefore, the untreated composite material does not exhibit the piezoelectric effect or exhibits a poor piezoelectric effect. Before use, it must be monodomainized at an appropriate temperature with a suitable electric field. The treatment is called polarization treatment, and even if the crystals are polar, this process is a necessary subsequent treatment process for piezoelectric polymers and piezoelectric composites. The ideal polarization treatment can make the spontaneous polarization of all parts of the whole crystal be aligned along the direction of the electric field.

In the present invention, the voltage applied for the polarization is 8-15 kV, and the time is 180-360 min.

The second aspect of the present invention provides an application of the piezoelectric-triboelectric coupling sensing material prepared by the above method in a piezoelectric-triboelectric coupling nanogenerator, specifically, the piezoelectric-triboelectric coupling sensing material is used as The positive electrode material of the piezoelectric-triboelectric coupled nanogenerator.

Further, the piezoelectric-triboelectric coupled nanogenerator also includes a negative electrode material, and the preparation method of the negative electrode material is: using dimethylformamide as a solvent, adding dimethylformamide at a mass fraction of 5 ~15% electronegative piezoelectric polymer and keep stirring until the solution becomes transparent, dry it, take it out and cool it to room temperature and let it stand; then add ethanol with 100% mass fraction of dimethylformamide for replacement, The deionized water with a mass fraction of dimethylformamide of 100% is replaced to obtain a hydrogel; the obtained hydrogel is dried to obtain an aerogel of an electronegative piezoelectric polymer, which is finally pressed into a film.

In the above technical solution, by applying mechanical stress such as pressure (tapping, re-tapping, bending), the HPC/CTS/CNT film and the electronegative piezoelectric polymer film can be separated and output electrical signals through continuous contact, and the film With the film as the stimulus-response mechanism carrier, the signal conversion between force and electricity is realized. This feature also makes the piezoelectric-triboelectric coupling sensing material an excellent material for information display and energy storage.

The electronegative piezoelectric polymer is polyvinylidene fluoride, polyvinylidene fluoride trifluoroethylene, etc., which are negatively charged to form a part of the entire triboelectric charge.

In order to replace completely, ethanol replacement and deionized water replacement were carried out several times respectively.

The pressure used to form the film by pressing is 5-10 MPa, and the time is 10-20 minutes.

Preferably, the electronegative piezoelectric polymer solution is poured into a polytetrafluoroethylene mold, sealed and dried. The hydrogel thus prepared is a polyvinylidene fluoride (PVDF) hydrogel. The drying temperature is 75-85°C, and the drying time is 1.5-3 hours.

Through the above technical scheme, the present invention achieves the following beneficial effects:

1. The sensing material of the present invention adopts HPC, CTS and CNT to prepare the positive electrode of the piezoelectric-triboelectric coupling sensing material and a thin film with piezoelectric properties, which has excellent mechanical properties and signal conversion properties.

2. The piezoelectric-triboelectric coupling sensing material prepared by the present invention is flexible and can be used as a stress-sensing electronic skin. On the one hand, it can supply power to it, and on the other hand, it can distinguish its contact pressure according to the change of output voltage.

3. The continuous contact and separation movement between the electronegative piezoelectric polymer film and the electropositive film material of the nanogenerator of the present invention enables the cross-laminated multilayer structure to achieve continuous AC output through external loading, and the piezoelectric-friction As the carrier of the stimulus-response mechanism, the electrically coupled sensing material realizes the hypersensitive response of the force, has high sensitivity and high output conversion performance, and can generate different signal outputs by applying mechanical pressure. It has a very wide response range and can be intuitive and accurate. to detect different levels of stress.

Description of drawings

Fig. 1 is the output situation of the nanogenerator of piezoelectric-triboelectric coupling that embodiment of the present invention and comparative example make under pure frictional state;

Fig. 2 is the output situation of the piezoelectric-triboelectric coupling nanogenerator that the embodiment of the present invention and comparative example make under different pressures;

Fig. 3 is the output situation of the nanogenerator of piezoelectric-triboelectric coupling that the embodiment of the present invention and comparative example make under different frequencies;

Fig. 4 is the working circuit of the piezoelectric-triboelectric coupled nanogenerator energy storage system prepared in the embodiment of the present invention and the comparative example.

Explanation of reference signs

1 capacitor, 2 rectifier, 3 load

Detailed ways

The specific implementation of the present invention will be described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

In the following embodiments, the polytetrafluoroethylene backing is cut from a polytetrafluoroethylene plate, and the divided backing is 5 cm long, 5 mm wide, and 1-2 mm high.

Example 1

S1: 2g of CTS was added to 87.5g of 1.5% acetic acid-water solution, stirred magnetically at room temperature until completely dissolved. Then, 10 g of HPC was slowly added to the above solution in 5 times every 30 min, and ultrasonic treatment was performed at room temperature. The solution was left standing at 10 ° C for 6 h, taken out and placed at room temperature, and 0.5 g of CNT was added. After magnetic stirring for 3 h, Stand at room temperature for 24 hours, then perform centrifugal degassing, the centrifugal degassing condition is 10kpm, 30min, to obtain HPC/CTS/CNT solution;

S2: Evenly cast the HPC/CTS/CNT solution obtained in S1 on a smooth and flat polytetrafluoroethylene substrate. The surface of the solution after casting should be parallel to the substrate, and then slowly place it in an oven at a temperature of 55°C for 8 hours. Lose water until it is cast into a film, then stand at room temperature for 2 hours, then remove the film and polarize it at a voltage of 12kV for 250 minutes to obtain a triboelectric positive electrode of piezoelectric-triboelectric coupling induction material with piezoelectric properties film;

S3: Using dimethylformamide as a solvent, add polyvinylidene fluoride with a mass fraction of dimethylformamide of 10% and continue to stir until the solution becomes transparent, pour it into a polytetrafluoroethylene mold and seal it at temperature Put it in an oven at 80°C for 3 hours; take it out, cool it to room temperature and let it stand at room temperature for 12 hours, then add ethanol with a mass fraction of dimethylformamide of 100% for replacement, seal it and let it stand for 6 hours, then pour it out, repeat 3 times ; Then add deionized water with a mass fraction of dimethylformamide of 100%, seal it and let it stand for 6 hours, then pour it out, repeat 3 times to obtain a PVDF hydrogel, and freeze-dry the obtained hydrogel to obtain an aerogel , and finally pressed for 15 minutes under a pressure of 10MPa;

S4: Paste copper sheet and polyimide tape on one side of the film obtained in S2 and S3 respectively, and then use two sponges (10*5*2mm) to separate the two films, and then package, and the specification is 22UF A 50V 5*11 capacitor 1 is connected to a rectifier 2 to obtain a piezoelectric-triboelectric coupled nanogenerator (as shown in FIG. 4 ).

Example 2

S1: Add 5g of CTS to 85g of 0.5% acetic acid-water solution, and magnetically stir for 30min at room temperature until completely dissolved. Then, 9 g of HPC was slowly added to the above solution in 9 times at intervals of 15 min, and ultrasonic treatment was performed at room temperature until the concentration reached 9%. , after magnetic stirring for 2 hours, let it stand at room temperature for 30 hours, and then perform centrifugal degassing, the centrifugal degassing condition is 8kpm, 30min, to obtain HPC/CTS/CNT solution;

S2: Evenly cast the HPC/CTS/CNT solution obtained in S1 on a smooth and flat polytetrafluoroethylene substrate. The surface of the solution after casting should be parallel to the substrate, and then slowly place it in an oven at a temperature of 50°C for 12 hours. Lose water until it is cast into a film, then let it stand at room temperature for 1 hour, remove the film and polarize it at 8kV for 360 minutes to obtain a triboelectric positive electrode of piezoelectric-triboelectric coupling sensing material with piezoelectric properties film;

S3: Using dimethylformamide as a solvent, add polyvinylidene fluoride trifluoroethylene with a mass fraction of dimethylformamide of 5% and continue to stir until the solution becomes transparent, pour it into a polytetrafluoroethylene mold and seal it. into an oven at 75°C for 3 hours. After taking it out, cool it to room temperature and let it stand at room temperature for 24 hours, then add ethanol with a mass fraction of dimethylformamide of 100% for replacement, seal it and let it stand for 6 hours, pour it out, and repeat 3 times; then add dimethylformamide Deionized water with an amide mass fraction of 100%, sealed and left to stand for 6 hours, then poured out, repeated 3 times to obtain a PVDF hydrogel, freeze-dried the obtained hydrogel to obtain an aerogel, and finally pressed it under a pressure of 5 MPa for 20 minutes .

S4: Paste copper sheet and polyimide tape on one side of the film obtained in S2 and S3 respectively, and then use two sponges (10*5*2mm) to separate the two films, and then package, and the specification is 22UF A 50V 5*11 capacitor 1 is connected to a rectifier 2 to obtain a piezoelectric-triboelectric coupled nanogenerator (as shown in FIG. 4 ).

Example 3

The preparation method of the piezoelectric-triboelectric coupling induction material comprises the following steps:

S1: 3g of CTS was added to 84.2g of 1.0% acetic acid-water solution, and magnetically stirred at room temperature for 45min until completely dissolved. Then 12g of HPC was slowly added to the above solution in 6 times at intervals of 20min, and ultrasonic treatment was performed at room temperature until the concentration reached 12%. CNT, after magnetic stirring for 6 hours, let it stand at room temperature for 27 hours, and then perform centrifugal degassing, the centrifugal degassing condition is 12kpm, 15min, to obtain HPC/CTS/CNT solution;

S2: Evenly cast the HPC/CTS/CNT solution obtained in S1 on a smooth and flat polytetrafluoroethylene substrate. The surface of the solution after casting should be parallel to the substrate, and then slowly place it in an oven at a temperature of 55°C for 6 hours. Lose water until it is cast into a film, then stand at room temperature for 2 hours, remove the film and polarize at a voltage of 15kV for 180 minutes to obtain a triboelectric positive electrode of piezoelectric-triboelectric coupling induction material with piezoelectric properties film;

S3: Using dimethylformamide as a solvent, add polyvinylidene fluoride with a mass fraction of dimethylformamide of 15% and continue to stir until the solution becomes transparent, pour it into a polytetrafluoroethylene mold and seal it at temperature 1.5h in an oven at 85°C. After taking it out, cool it to room temperature and let it stand at room temperature for 24 hours, then add ethanol with a mass fraction of dimethylformamide of 100% for replacement, seal it and let it stand for 6 hours, pour it out, and repeat 3 times; then add dimethylformamide Deionized water with a amide mass fraction of 100%, sealed and left to stand for 6 hours, poured out, repeated 3 times to obtain a PVDF hydrogel, freeze-dried the obtained hydrogel to obtain an aerogel, and finally pressed it under a pressure of 10MPa for 10 minutes .

S4: Paste copper sheet and polyimide tape on one side of the film obtained in S2 and S3 respectively, and then use two sponges (10*5*2mm) to separate the two films, and then package, and the specification is 22UF A 50V 5*11 capacitor 1 is connected to a rectifier 2 to obtain a piezoelectric-triboelectric coupled nanogenerator (as shown in FIG. 4 ).

Comparative example 1

The positive electrode film of the piezoelectric-triboelectric coupling sensing material in Example 1 is replaced by a polyester film, and the other is the same as in Example 1.

Comparative example 2

The electronegative piezoelectric polymer film in Example 1 was replaced by a PDMS film, and the others were the same as in Example 1.

Comparative example 3

In 2019, Yousry's team at the Singapore Institute of Materials Research and Engineering (Agency for Science, Technology and Research) proposed a theoretical model of piezoelectric and triboelectric composite power generation mechanisms based on electrospun PVDF fiber films (Yousry Y M, Yao K, Mohamed A M, et al. Theoretical model and outstanding performance from constructive piezoelectric and triboelectric mechanism in electrospun PVDF fiber film [J]. Advanced Functional Materials, 2020, 30(25): 1910592.). Their research started from a systematic theoretical analysis, established a theoretical model, and clarified the structural piezoelectric-triode mechanism of polarized PVDF optical fiber films, thus explaining the experimental observations well. The electrospinning process induced the polarization orientation, which modulated the electron affinity of PVDF fibers with different polarized ends, resulting in piezoelectric and trielectric structural responses of PVDF fiber films. The output voltage of the generator device is about 4V at the frequency of 100Hz, compared with it, the present invention has superior electrical signal output performance.

performance testing

The piezoelectric-triboelectrically coupled nanogenerators made in Example 1-Example 3 and Comparative Example 1-Comparative Example 2 are connected to a load 3 (as shown in Figure 4), and by controlling the vibration frequency and the size of the pressure (SH- III-500N), to characterize the sensitivity and stability of the piezoelectric-triboelectric coupling generator, the specific method is: respectively paste two conductive tapes on the copper sheets of the two films, and then connect the conductive tape to the electrometer (EST102 , Beijing Hua Testing Experimental Instrument Co., Ltd.) connected to the two ends of the conductive clip to measure the voltage of the piezoelectric-triboelectric coupling generator in the pressure working mode (as shown in Figure 2). In the range of 25-150N, the piezoelectric-triboelectric coupled generator is subjected to repeated pressing tests with different pressures, and the value and stability of the voltage are observed through repeated pressing tests. The specific test results are shown in Figure 2-Figure 3 and Table 1.

Table 1 performance test results

It can be seen from Table 1 that as the pressure increases, the output voltage of the generator also increases gradually, reaching a peak value at 150N, and the stability of the voltage changes very little with the increase of pressure.

It can be seen from Figure 2 that the test is carried out within the pressure range of 25-150N, and the voltage value change under different pressures and the stability of the output voltage under the same pressure are observed through repeated pressing tests. It can be found that with the increase of the pressure, the output voltage of the piezoelectric-triboelectric coupled nanogenerator also increases gradually, reaching a peak value at a pressure of 150N, and the output voltage is 20V. Under the same pressure, the output voltage is relatively stable as a whole, which shows that the piezoelectric-triboelectric coupled nanogenerator is very sensitive to different pressures and has the characteristics of high sensitivity, but the voltage output under the same pressure is also stable. .

As shown in Figure 3, in the range of 0.75 to 1.25 Hz, the same magnitude of pressure is applied to the piezoelectric-triboelectric coupled nanogenerator to conduct repeated tests at different frequencies, and the voltage output at different frequencies is observed through repeated tests. Stability, it can be found that with the increase of the frequency, the output voltage of the piezoelectric-triboelectric coupled nanogenerator is almost unchanged, and the output voltage is stable in the range of 10V-11V.

At the same time, the output voltage in pure triboelectric mode (as shown in Figure 1) was also measured. It can be seen that under the same pressure (25-75N), the output (5-8V) voltage of pure triboelectric mode is much lower than Piezo-triboelectric coupling (6.5-10V).

It can be seen from the above description that the piezoelectric-triboelectric coupled nanogenerator of the present invention has superior output performance and strong stability, and can display the change of external pressure stably and intuitively at the same time as its output voltage. sensitivity. In addition, the invention is flexible and can be used as a stress-sensing electronic skin or a sensor. On the one hand, it can supply power to it, and on the other hand, it can distinguish its contact pressure according to the change of output voltage.

The preferred implementation of the present invention has been described in detail above in conjunction with the examples, but the present invention is not limited to the details of the above-mentioned implementation, within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, These simple modifications all belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way if there is no contradiction. The combination method will not be described separately.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (10)

1. The preparation method of the piezoelectric-triboelectric coupling induction material is characterized by comprising the following steps of:

s1: dissolving hydroxypropyl cellulose, chitosan and carbon nano tube in an acid solution to prepare a hydroxypropyl cellulose/chitosan/carbon nano tube solution;

s2: and (3) casting the hydroxypropyl cellulose/chitosan/carbon nanotube solution on a polytetrafluoroethylene substrate for drying to obtain the piezoelectric-triboelectric coupling induction material.

2. The method for preparing a piezoelectric-triboelectric coupling sensing material according to claim 1, wherein in step S1, the method for preparing the hydroxypropyl cellulose/chitosan/carbon nanotube solution comprises: dissolving chitosan in an acid solution with the acid concentration of 0.5-1.5%, then adding hydroxypropyl cellulose into the solution in batches, uniformly mixing the solution, and finally adding carbon nano tubes and uniformly mixing the solution; the concentration of chitosan in the hydroxypropyl cellulose/chitosan/carbon nano tube solution is 2-5%, the concentration of hydroxypropyl cellulose is 9-12%, and the concentration of carbon nano tube is 0.5-1%.

3. The method of preparing a piezoelectric-triboelectric coupling sensing material according to claim 2, wherein each time the hydroxypropyl cellulose is added for 15-30 min, and the ultrasonic treatment is performed at a temperature lower than 30 ℃.

4. The method for preparing a piezoelectric-triboelectric coupling induction material according to claim 2, wherein the solution is allowed to stand at 0-10 ℃ for 3-6 hours after the completion of the addition and the uniform mixing of the hydroxypropyl cellulose, and the solution is allowed to stand at room temperature for 24-30 hours after the completion of the addition and the uniform mixing of the carbon nanotubes, and then subjected to degassing treatment.

5. The method for preparing a piezoelectric-triboelectric coupling induction material according to claim 1, wherein in the step S2, a solution of hydroxypropyl cellulose/chitosan/carbon nanotube is cast on a polytetrafluoroethylene substrate, the surface of the cast solution is parallel to the substrate, water is lost until the casting is carried out to form a film, and the film is taken off and polarized after standing for 1-2 hours at room temperature to obtain the piezoelectric-triboelectric coupling induction material film.

6. The method for preparing a piezoelectric-triboelectric coupling induction material according to claim 5, wherein the voltage applied by the polarization is 8-15 kV for 180-360 min.

7. Use of a piezoelectric-triboelectric coupling induction material prepared according to any one of claims 1 to 6 in a piezoelectric-triboelectric coupling nano-generator, characterized in that the piezoelectric-triboelectric coupling induction material is used as a positive electrode material of the piezoelectric-triboelectric coupling nano-generator.

8. The use of claim 7, wherein the piezoelectric-triboelectric coupled nano-generator further comprises a negative electrode material, the preparation method of the negative electrode material is as follows: taking dimethylformamide as a solvent, adding an electronegative piezoelectric polymer accounting for 5-15% of the mass fraction of the dimethylformamide, continuously stirring until the solution becomes transparent, drying, taking out, cooling to room temperature and standing; then adding ethanol with the mass fraction of 100% of dimethylformamide for replacement, and adding deionized water with the mass fraction of 100% of dimethylformamide for replacement to obtain hydrogel; and drying the obtained hydrogel to obtain the aerogel of the electronegative piezoelectric polymer, and finally pressing the aerogel into a film.

9. The use according to claim 8, wherein the electronegative piezoelectric polymer solution is poured into a polytetrafluoroethylene mould, sealed and baked.

10. The use according to claim 8, wherein the electronegative piezoelectric polymer is polyvinylidene fluoride or polyvinylidene fluoride trifluoroethylene.

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