Friction nanometer generator applied to flexible wearable equipment

Abstract

The invention discloses a high-performance friction nano-generator, which adopts a symmetrical sandwich structure design and comprises two PU / Ag / Cu composite positive electrode layers and a PDMS / CN / F-CNTs composite negative electrode layer, and a positive electrode-PTFE-negative electrode-PTFE-positive electrode configuration is formed by alternately overlapping PTFE isolation layers with the thickness of 30-80 microns. The positive electrode material is of a coaxial three-layer structure, takes a copper core as a base, and is sequentially coated with a nano-silver layer and a polyurethane protection layer; the negative electrode material is prepared by performing ultrasonic dispersion and high-temperature calcination on CN and F-CNTs to form a pinning interlocking structure, and compounding the pinning interlocking structure with PDMS. By optimizing the area ratio of the positive electrode to the negative electrode, the CN / F-CNTs ratio and centrifugal treatment, the frictional charge density and the mechanical stability are remarkably improved. The generator has high output efficiency and durability, and is suitable for the fields of flexible electronics, self-powered sensors and biological mechanical energy collection.

Description

Technical Field

[0001] This invention relates to the field of nanoenergy and flexible electronic device technology, specifically to a triboelectric nanogenerator for flexible wearable devices and its preparation method. Background Technology

[0002] With the rapid development of flexible electronics technology, triboelectric nanogenerators (TENGs) have become an ideal power solution for wearable devices due to their ability to convert environmental mechanical energy into electrical energy. TENGs operate based on contact electrification and electrostatic induction effects. When two different materials come into contact and separate, charge transfer occurs due to differences in electron affinity, which is collected through electrodes to form a current output. Compared with traditional electromagnetic generators, TENGs have advantages such as simple structure, light weight, and flexible material selection, making them particularly suitable for harvesting low-frequency mechanical energy such as human movement.

[0003] Currently, flexible TENGs mainly employ polymer-based composite material systems, commonly using polydimethylsiloxane (PDMS) and polyurethane (PU) as friction layer materials, combined with metal nanowires or carbon-based materials to construct flexible electrodes. However, existing technologies still have significant shortcomings when applied to wearable applications: First, the inherent charge density of the material system is low, making it difficult to meet actual requirements for output voltage and power; second, under repeated mechanical deformation conditions, electrode materials are prone to fatigue fracture, affecting the long-term stability of the device. In the design of negative electrode materials, although the PDMS-carbon nanotube (CNT) composite system is widely used, the lack of an effective charge trapping control mechanism results in a high charge recombination rate, limiting performance improvement. In the positive electrode materials, silver nanowires (AgNWs) or pure metal films are often used. Although they have good conductivity, they are expensive and have weak interfacial bonding with the polymer matrix, making them prone to peeling during stretching. Traditional planar thin film structures are difficult to adapt to complex deformations, while novel spiral or fibrous electrodes face problems such as complex fabrication processes, easy material oxidation, or poor environmental stability.

[0004] These technical shortcomings severely restrict the practical application of TENGs in the wearable field. From an application perspective, an ideal flexible TENG needs to simultaneously meet the following requirements: high output performance to ensure sufficient power supply; excellent mechanical adaptability to withstand various deformations; long-term stability to guarantee service life; good environmental adaptability to cope with temperature and humidity changes; and sufficient comfort for wearing. Existing technologies do not perform satisfactorily in these aspects.

[0005] Therefore, developing novel flexible TENG material systems and device structures has become a current research focus. This requires innovation in multiple dimensions, including material selection, interface engineering, and structural design: at the material level, it is necessary to develop novel composite materials that combine high triboelectric properties with excellent mechanical properties; in terms of interface engineering, it is necessary to optimize the electrode-dielectric interface to improve charge transfer efficiency; and in terms of structural design, it is necessary to develop more ergonomic device configurations to promote the practical application of flexible TENGs in wearable devices. Summary of the Invention

[0006] Technical problem to be solved: The purpose of this invention is to provide a nanogenerator for flexible wearables, which solves the problems of low power density, poor mechanical flexibility and insufficient comfort for long-term wear of existing flexible nanogenerators.

[0007] Technical solution: A triboelectric nanogenerator, comprising two PU / Ag / Cu composite positive electrode materials and one PDMS / C3N5 / F-CNTs composite negative electrode material, and a PTFE insulating layer disposed between the positive and negative electrodes. The PTFE insulating layer alternately stacks the two positive electrode materials and one negative electrode material to form a symmetrical sandwich structure of "positive electrode-PTFE-negative electrode-PTFE-positive electrode". The thickness of the PTFE insulating layer is 30-80 μm, and the ratio of the positive electrode layer area to the negative electrode layer area is (1.8-2.2):1.

[0008] The substrate of the aforementioned PDMS / C3N5 / F-CNTs composite anode material is PDMS, in which C3N5 and F-CNTs are uniformly distributed. And / or, The aforementioned PU / Ag / Cu composite cathode material has a coaxial three-layer structure, consisting of a high-purity copper core, a silver layer, and a polyurethane protective layer, arranged sequentially from the core layer to the outer layer.

[0009] Preferably, the preparation method of the negative electrode material of the above-mentioned triboelectric nanogenerator includes the following steps: S1. C3N5 nanosheets and F-CNTs were added to an isopropanol solution and dispersed uniformly by ultrasonic dispersion to obtain a mixed dispersion. The mixture was washed with ethanol and deionized water and filtered. After drying, it was ground into a uniform powder and then calcined at high temperature under a reducing atmosphere to form a "pinned" interlocking structure between C3N5 nanosheets and F-CNTs. S2. The C3N5 / F-CNTs “pinned” interlocking structure powder obtained in step S1 is mixed with vinyl-terminated polydimethylsiloxane at a mass ratio. The powder is uniformly distributed in the vinyl-terminated polydimethylsiloxane by mechanical stirring and ultrasound. Then, a hydrogen-containing silicone oil crosslinking agent in proportion to the vinyl-terminated polydimethylsiloxane is added and mechanically stirred to form a mixture. S3. The mixture from step S2 is subjected to vacuum degassing treatment, then injected into a molding mold and placed in a temperature-controlled environment for heating and curing to form a base material; Preferably, the preparation method of the positive electrode material of the above-mentioned triboelectric nanogenerator includes the following steps: S11. After cleaning the copper wire, immerse it in silver ammonia solution containing temperature-sensitive polymer and glucose-PVP mixture in sequence. Through temperature-controlled gradient chemical plating process, a three-dimensional network structure silver plating layer is deposited on its surface. S12. The silver-plated copper wire from step S11 is immersed in a polyurethane / DMF mixed solution of a preset concentration to form a continuous polymer coating layer on its surface. Then, it undergoes preliminary drying and segmented temperature-controlled curing to obtain the positive electrode material.

[0010] Preferably, in step S1, the ultrasonic power is 250-400 W, the ultrasonic time is 30-90 min, the mass ratio of C3N5 nanosheets to CNTs-F is 1:0.5-1:2, the solid-liquid ratio of isopropanol to the mixed material is 1 g : 120-180 ml, the calcination temperature is 500-800℃, and the calcination time is 1-3 h, so that the C3N5 nanosheets and F-CNTs form a pinned interlocking structure. The obtained C3N5 / F-CNTs "pinned" interlocking structure powder is mixed with PDMS prepolymer according to a preset ratio, and the filler is uniformly distributed in the prepolymer by mechanical shearing.

[0011] Preferably, in step S2, the mass ratio of C3N5 / F-CNTs “pinned” interlocking structure powder to vinyl-terminated polydimethylsiloxane is 5:1-15:1, the mechanical stirring speed is 500-1000 r / min, the time is 30-120 min, and the ultrasonic dispersion time is 20-40 min; the mass ratio of vinyl-terminated polydimethylsiloxane to hydrogen-containing silicone oil crosslinking agent is 10:1, and the mechanical stirring speed is 300-600 r / min.

[0012] Preferably, the vacuum degree of the vacuum degassing process in S3 is -0.08 to -0.10 MPa, the degassing time is 10-30 min, the heating and curing temperature is 60-100 ℃, and the time is 1-4 h.

[0013] Preferably, in step S11: the silver ion concentration of the silver ammonia solution is 0.1-0.5 mol / L, the temperature-sensitive polymer is poly(N-isopropylacrylamide) with a concentration of 1-5 wt%; the glucose concentration in the glucose-PVP mixture is 0.3-0.7 mol / L, the polyvinylpyrrolidone has a molecular weight of 8000-50000 and a concentration of 0.1-0.5 mol / L; and / or, The gradient electroless plating process consists of three stages: the first stage is immersion at a low temperature of 5-15℃ for 10-30 min to form crystal nuclei; the second stage is reaction at 25-35℃ for 20-40 min to build a three-dimensional framework; and the third stage is high-temperature strengthening at 45-60℃ for 15-25 min to complete the growth of the network structure.

[0014] Preferably, in step S12: the concentration of the polyurethane / DMF mixed solution is 10-30 wt%, the impregnation time is 0.5-5 min; the preliminary drying treatment uses hot air drying at 50-70℃ for 3-15 min, with an air velocity of 2-5 m / s; and / or, The segmented temperature-controlled curing process includes: Stage 1: 40-60℃ constant temperature for 20-60 min; Stage 2: 70-90℃ constant temperature for 1-4 h; Stage 3: 100-120℃ constant temperature for 0.5-3 h; The heating rate between each stage is 0.5-3℃ / min.

[0015] The aforementioned triboelectric nanogenerators are used in flexible wearable devices.

[0016] Beneficial effects: The triboelectric nanogenerator of the present invention has the following advantages: 1. The composite cathode of the present invention constructs a three-dimensional network silver layer on the surface of copper wire through a temperature-controlled gradient chemical plating process, forming a conductive network structure with a high specific surface area, which significantly improves the charge collection capability of the electrode while maintaining excellent flexibility and mechanical strength. 2. The composite negative electrode material of the present invention optimizes charge capture performance: it adopts a "pinned" interlocking structure formed by C3N5 nanosheets and F-CNTs in a PDMS matrix, combined with the surface micromorphology constructed by gradient centrifugation process, to achieve efficient charge capture and storage and ensure stable electrical output; 3. The multi-layer structure design of this invention enhances environmental adaptability: Through the precise assembly of the PTFE isolation layer and the symmetrical sandwich structure, the interlayer interface characteristics are optimized. It is prepared by a completely physical process without any chemical cross-linking agents, thus meeting the biocompatibility requirements of wearable devices. Attached Figure Description

[0017] Figure 1 The electrical performance output of the generator in Example 1 in the frequency range of 0.5-2.5 Hz includes: (a) short-circuit current; (b) open-circuit voltage; and (c) output power. Figure 2 The open-circuit voltages of the generator in Example 1 with friction areas of 1cm×1cm, 2cm×2cm, and 3cm×3cm respectively; Figure 3 For the stability test of the triboelectric nanogenerator in Example 1 during use, the output voltage was measured after 100,000 triboelectric cycles. Figure 4 The electrical output performance of the triboelectric nanogenerator obtained in Example 1 under different pressures (1-7 N) includes: (a) short-circuit current; (b) open-circuit voltage; and (c) output power. Detailed Implementation

[0018] The present invention will be further described below with reference to embodiments. These embodiments are illustrative of the present invention, but the present invention is not limited to these embodiments: This invention provides a triboelectric nanogenerator, comprising two PU / Ag / Cu composite positive electrode materials and one PDMS / C3N5 / F-CNTs composite negative electrode material, as well as a PTFE insulating layer disposed between the positive and negative electrodes. The PTFE insulating layer alternately stacks the two positive electrode materials with one negative electrode material to form a symmetrical sandwich structure of "positive electrode-PTFE-negative electrode-PTFE-positive electrode". The charge generation and transport system design of the positive electrode PU / Ag / Cu composite material features a coaxial three-layer structure: as a flexible conductive framework, copper's high ductility adapts to dynamic deformation while providing a low-resistance pathway; a porous network structure of silver layer is formed through temperature gradient chemical plating, providing a through-type electron transport channel with a higher specific surface area than traditional plating, significantly enhancing contact charging efficiency; the PU protective layer forms a gradient match with the silver layer, inhibiting crack propagation while isolating oxygen and moisture to prevent silver layer oxidation failure. A charge-trapping optimized negative electrode material PDMS / C3N5 / F-CNTs composite system: High electron affinity C3N5 nanosheets serve as charge-trapping sites, forming a "pinned" interlocking structure with F-CNTs through high-temperature calcination, reducing charge recombination rate; F-CNTs impart hydrophobicity, reducing environmental humidity interference, and form a local electric field through sp³ hybridization defects, promoting directional charge migration; C3N5 and F-CNTs are covalently linked to form a three-dimensional conductive pathway. Gradient centrifugation is used to form regular protrusions on the PDMS surface, increasing the contact area and improving triboelectric efficiency; a slightly larger positive electrode area (1.8-2.2 times that of the negative electrode) ensures that the charge generated by the positive electrode is sufficient to match the charge-trapping capacity of the negative electrode, avoiding charge accumulation leading to built-in potential saturation and improving output stability. In the symmetrical "positive electrode-PTFE-negative electrode-PTFE-positive electrode" structure, the double positive electrodes sandwich the negative electrode to form a bidirectional electric field; the area ratio optimizes the electric field distribution, reduces unilateral charge accumulation, and enhances the symmetry of the output voltage waveform. The PTFE isolation layer is optimized by forming a controllable gap symmetrical sandwich structure through hot pressing synthesis. The low surface energy of PTFE reduces the contact separation adhesion force, ensuring efficient energy conversion. The symmetrical layout of the double positive electrode sandwiching the negative electrode forms a bidirectional electric field, reducing the built-in potential saturation phenomenon caused by charge accumulation and improving the symmetry of the output voltage waveform.

[0019] The above-mentioned triboelectric nanogenerator, the method for preparing the negative electrode material includes the following steps: S1. C3N5 nanosheets and F-CNTs were added to an isopropanol solution and dispersed uniformly by ultrasonic dispersion to obtain a mixed dispersion. The mixture was washed with ethanol and deionized water and filtered. After drying, it was ground into a uniform powder and then calcined at high temperature under a reducing atmosphere to form a "pinned" interlocking structure between C3N5 nanosheets and F-CNTs. S2. The C3N5 / F-CNTs “pinned” interlocking structure powder obtained in step S1 is mixed with vinyl-terminated polydimethylsiloxane at a mass ratio. The powder is uniformly distributed in the vinyl-terminated polydimethylsiloxane by mechanical stirring and ultrasound. Then, a hydrogen-containing silicone oil crosslinking agent in proportion to the vinyl-terminated polydimethylsiloxane is added and mechanically stirred to form a mixture. S3. The mixture from step S2 is subjected to vacuum degassing treatment, then injected into a molding mold and placed in a temperature-controlled environment for heating and curing to form a base material.

[0020] The isopropanol added in step S1 above works by reducing polarity to inhibit van der Waals aggregation of C3N5 nanosheets and F-CNTs, and by combining it with ultrasound to achieve physical dispersion of nano-components; high-temperature calcination inhibits the denitrification and decomposition of C3N5, and drives the diffusion of fluorine atoms on the surface of F-CNTs to embed into the lattice defects of C3N5, forming a "pinned" interlocking structure anchored by CFN covalent bonds. In step S2 above, the vinyl-terminated PDMS polymer chains encapsulate the nanoparticles through mechanical stirring and ultrasonication, forming an "island structure." Vinyl-PDMS and hydrogen-containing silicone oil then form a three-dimensional cross-linked network through a hydrosilylation reaction, enhancing the mechanical strength of the substrate. In step S3 above, the vacuum degassing process is carried out in a negative pressure environment to avoid pores after curing and to ensure the stability of the material.

[0021] The above-mentioned triboelectric nanogenerator, the preparation method of the positive electrode material includes the following steps: S11. After cleaning the copper wire, immerse it in silver ammonia solution containing temperature-sensitive polymer and glucose-PVP mixture in sequence. Through temperature-controlled gradient chemical plating process, a three-dimensional network structure silver plating layer is deposited on its surface. S12. The silver-plated copper wire from step S11 is immersed in a polyurethane / DMF mixed solution of a preset concentration to form a continuous polymer coating layer on its surface. Then, it undergoes preliminary drying and segmented temperature-controlled curing to obtain the positive electrode material.

[0022] In step S11 above, instead of the traditional method of silver coating copper to form a dense layer, a temperature-controlled chemical plating layer is used to form a three-dimensional network of silver. A silver ammonia solution provides Ag⁺, glucose acts as a reducing agent, and PVP regulates the directional growth of silver particles. A temperature gradient induces non-uniform nucleation, prompting the silver particles to self-assemble into a three-dimensional porous network. In step S12 above, the polyurethane / DMF solution impregnates to form a continuous coating layer. After the DMF solvent evaporates, the polyurethane bonds with the silver layer through hydrogen bonds, inhibiting crack propagation.

[0023] In one embodiment, in step S1, the C3N5 to F-CNTs mass ratio of 1:0.5-1:2 optimizes the pinning site density; the isopropanol solid-liquid ratio of 120-180:1 g / mL inhibits aggregation; calcination at 500-800℃ promotes the insertion of fluorine atoms into C3N5, forming a pinned structure and preventing decomposition. Mechanical shearing of mixed PDMS constructs a conductive network and maintains the degree of crosslinking, improving charge transport and mechanical properties.

[0024] In one embodiment, in step S2, the mass ratio of C3N5 / F-CNTs to vinyl PDMS is 5:1-15:1 to ensure percolation distribution of the filler, forming a continuous conductive network while maintaining the degree of crosslinking; mechanical stirring at 500-1000 r / min for 30-120 min disperses the filler uniformly through high shear force; ultrasonic dispersion for 20-40 min dissociates residual agglomerates and strengthens pinning bonds; the crosslinking density is precisely controlled by a PDMS to hydrogen-containing silicone oil ratio of 10:1 and stirring at 300-600 r / min to suppress bubble formation.

[0025] In one embodiment, during vacuum degassing (-0.08~-0.10 MPa, 10-30 min) in step S3, -0.08 MPa removes large-sized bubbles, and -0.10 MPa further eliminates micron-sized bubbles, preventing solidification pores; degassing time that is too short or too long will lead to defects. Heat curing (60-100℃, 1-4 h) triggers initial crosslinking of PDMS, accelerates crosslinking, and inhibits thermal stress microcracks; crosslinking is completed within 4 h to avoid molecular chain breakage.

[0026] In one embodiment, in step S11, the Ag⁺ concentration in the silver ammonia solution is 0.1-0.5 mol / L. A 0.1 mol / L Ag⁺ concentration ensures crystal nucleus density, while a 0.5 mol / L concentration inhibits particle agglomeration. The glucose concentration is 0.3-0.7 mol / L to control the reduction rate and prevent the silver layer from becoming porous. The PVP molecular weight is 8000-50000, with low molecular weight controlling crystal face growth and high molecular weight inhibiting agglomeration; its concentration is 0.1-0.5 mol / L. Gradient electroless plating is performed in three stages: at a low temperature of 5-15℃, PNIPAM adsorbs Ag⁺ for nucleation, and PVP directionally controls the crystal face; at a medium temperature of 25-35℃, PNIPAM undergoes a phase transition to release Ag⁺, accelerating reduction and forming a three-dimensional dendritic framework; at a high temperature of 45-60℃, silver particles self-assemble into a porous network structure, and PVP pyrolysis reduces carbon impurities, improving the conductivity and mechanical strength of the silver layer.

[0027] In one embodiment, the concentration of the polyurethane / DMF mixed solution in step S12 is controlled at 10-30 wt%. The solution viscosity is adjusted to achieve uniform coating of the copper wire surface while avoiding excessive coating thickness. The immersion time is 0.5-5 min to ensure proper wetting without damaging the silver layer. Preliminary drying uses hot air at 50-70℃ with a wind speed of 2-5 m / s, completing solvent evaporation within 3-15 min to prevent surface defects. Segmented temperature-controlled curing is performed in three stages: the first stage at 40-60℃ forms a flexible network; the second stage at 70-90℃ enhances cross-linking density; and the third stage at 100-120℃ eliminates residual stress. The temperature is increased at a rate of 0.5-3℃ / min between each stage to balance thermal stress and process efficiency. This parameter system synergistically achieves the density, strong interfacial bonding, and thermomechanical stability of the coating layer.

[0028] Example 1

[0029] A method for preparing a triboelectric nanogenerator includes the following steps: The triboelectric nanogenerator includes two PU / Ag / Cu composite positive electrode materials and one PDMS / C3N5 / F-CNTs composite negative electrode material, as well as a PTFE isolation layer disposed between the positive and negative electrodes. The PTFE isolation layer alternately stacks the two positive electrode materials and one negative electrode material to form a symmetrical sandwich structure of "positive electrode-PTFE-negative electrode-PTFE-positive electrode". The method for preparing the negative electrode material of the triboelectric nanogenerator includes the following steps: S1. C3N5 nanosheets and F-CNTs were added to an isopropanol solution at a mass ratio of 1:1 (solid-liquid ratio of isopropanol to mixed material: 1 g: 150 mL). The mixture was ultrasonically dispersed for 60 min, then washed successively with ethanol and deionized water, filtered, dried, and ground into a uniform powder. Subsequently, it was calcined at 600℃ for 1.5 h under argon protection to form a "pinned" interlocking structure between the C3N5 nanosheets and F-CNTs. S2. The C3N5 nanosheets and F-CNTs powder prepared in step S1 are mixed with vinyl PDMS at a mass ratio of 10:1 by mechanical stirring at 600 r / min for 70 min to uniformly disperse the filler under high shear force; the residual agglomerates are dissociated by ultrasonic dispersion for 30 min to strengthen the pinning bonds; and a mixed solution is formed. S3 The mixture prepared in step S2 is subjected to vacuum degassing at a pressure of -0.10 MPa for 20 min. Then it is injected into a molding mold and placed in a temperature-controlled environment for heating and curing to form a base material. The heating and curing temperature is 80 ℃ and the time is 2 h; thus, the negative electrode material of the triboelectric nanoelectrode is obtained. The method for preparing the positive electrode material of the aforementioned triboelectric nanogenerator includes the following steps: S11. After cleaning the copper wire, it is sequentially immersed in a silver ammonia solution containing a temperature-sensitive polymer and a glucose-PVP mixture. The silver ammonia solution contains 0.3 mol / L silver ions, 0.5 mol / L glucose, and 0.2 mol / L PVP with a molecular weight of 20,000. A three-dimensional network structure silver plating layer is deposited on its surface using a temperature-controlled gradient electroless plating process. The gradient electroless plating is divided into three stages: low temperature (10℃, 10 min); medium temperature (10℃, 20 min); and high temperature (50℃, 15 min). S12. The silver-plated copper wire from step S11 is immersed in a polyurethane / DMF mixed solution of a preset concentration, controlled at 20 wt%, to form a continuous polymer coating layer on its surface. Then, it undergoes preliminary drying at 60℃, followed by segmented temperature-controlled curing to obtain the positive electrode material. The gradient chemical plating is divided into three stages: low temperature is set at 50℃ for 40 min; medium temperature is set at 80℃ for 2 h; and high temperature is set at 110℃ for 1.5 h to obtain the positive electrode material of the triboelectric nanoelectrode.

[0030] Example 2

[0031] The difference between Example 2 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:0.5, and the solid-liquid ratio of isopropanol to the mixed material is 1g:120mL.

[0032] Example 3

[0033] The difference between Example 3 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:0.5, and the solid-liquid ratio of isopropanol to the mixed material is 1g:130mL.

[0034] Example 4

[0035] The difference between Example 4 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:1, and the solid-liquid ratio of isopropanol to the mixed material is 1g:140mL.

[0036] Example 5

[0037] The difference between Example 5 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:1, and the solid-liquid ratio of isopropanol to the mixed material is 1g:150mL.

[0038] Example 6

[0039] The difference between Example 6 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:2, and the solid-liquid ratio of isopropanol to the mixed material is 1g:160mL.

[0040] Example 7

[0041] The difference between Example 7 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:2, and the solid-liquid ratio of isopropanol to the mixed material is 1g:180mL.

[0042] Example 8

[0043] The difference between Example 8 and Example 1 is that the calcination temperature in step S1 is 500℃.

[0044] Example 9

[0045] The difference between Example 9 and Example 1 is that the calcination temperature in step S1 is 800℃.

[0046] Example 10

[0047] The difference between Example 10 and Example 1 is that the heating and curing temperature in step S3 is 60 ℃ and the time is 1 h.

[0048] Example 11

[0049] The difference between Example 11 and Example 1 is that the heating and curing temperature in step S3 is 100 ℃ and the time is 4 h.

[0050] Example 12

[0051] The difference between Example 12 and Example 1 is that in step S11, the silver ion concentration in the silver ammonia solution is 0.1 mol / L and the glucose concentration is 0.3 mol / L.

[0052] Example 13

[0053] The difference between Example 13 and Example 1 is that the silver ion concentration in the silver ammonia solution in step S11 is 0.5 mol / L and the glucose concentration is 0.7 mol / L.

[0054] Example 14

[0055] The difference between Example 14 and Example 1 is that the concentration of the polyurethane / DMF mixed solution in step S12 is controlled at 10 wt%.

[0056] Example 15

[0057] The difference between Example 15 and Example 1 is that the concentration of the polyurethane / DMF mixed solution in step S12 is controlled at 30 wt%.

[0058] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:0.1, and the solid-liquid ratio of isopropanol to the mixed material is 1g:50mL.

[0059] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:5, and the solid-liquid ratio of isopropanol to the mixed material is 1g:500mL.

[0060] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:0.1, and the solid-liquid ratio of isopropanol to the mixed material is 1g:120mL.

[0061] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that in step S1, C3N5 nanosheets and F-CNTs are added to isopropanol at a mass ratio of 1:5, and the solid-liquid ratio of isopropanol to the mixed material is 1g:180mL.

[0062] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the heating and curing temperature in step S3 is 500 °C and the time is 1 hour.

[0063] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that the silver ion concentration in the silver ammonia solution in step S11 is 0.05 mol / L and the glucose concentration is 0.01 mol / L.

[0064] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is that the silver ion concentration in the silver ammonia solution in step S11 is 2 mol / L and the glucose concentration is 2 mol / L.

[0065] Comparative Example 8 The difference between Comparative Example 8 and Example 1 is that the concentration of the polyurethane / DMF mixed solution in step S12 is controlled at 5 wt%.

[0066] Comparative Example 9 The difference between Comparative Example 9 and Example 1 is that the concentration of the polyurethane / DMF mixed solution in step S12 is controlled at 50 wt%.

[0067] Comparative Example 10 The difference between Comparative Example 10 and Example 1 is that C3N5 composite nanomaterials are not added to the negative electrode material of a triboelectric nanoelectrode.

[0068] Comparative Example 11 The difference between Comparative Example 11 and Example 1 is that C3N5 nanosheets and F-CNTs are mixed in a mass ratio in the negative electrode material of a triboelectric nanoelectrode, but isopropanol solution is not added.

[0069] Comparative Example 12 The difference between Comparative Example 12 and Example 1 is that the chemical process in S11 is not controlled by gradient temperature, and the temperature is set to 60°C and the time is 1 hour.

[0070] Comparative Example 13 The difference between Comparative Example 13 and Example 1 is that the triboelectric nanogenerator only includes a PU / Ag / Cu composite positive electrode material and a PDMS / C3N5 / F-CNTs composite negative electrode material, as well as a PTFE insulating layer disposed between the positive and negative electrodes.

[0071] Comparative Example 14 The difference between Comparative Example 14 and Example 1 is that the triboelectric nanogenerator consists of only two PU / Ag / Cu composite cathode materials and one PDMS / C3N5 / F-CNTs composite anode material. It does not include a PTFE insulating layer.

[0072] Performance testing: Test Example 1 Electrical output performance testing: The electrical output response of triboelectric nanogenerator was measured using a Keithley 6514 electrometer.

[0073] By analyzing the characteristics of current changing with time at different frequencies, Figure 1 (ac) illustrates the electrical output performance of a triboelectric nanogenerator in the 0.5–2.5 Hz frequency range, revealing the significant influence of frequency on the output response. From Figure 1As shown in (a), the short-circuit current amplitude of the TENG exhibits a significant monotonically increasing trend with increasing external excitation frequency. This phenomenon is mainly due to the fact that the increase in frequency directly accelerates the contact-separation cycle rate between the friction layers. The higher separation speed effectively shortens the relaxation time window of charge return, while the number of effective contact-separation events occurring per unit time increases. These two factors work synergistically to significantly improve the charge transfer rate, ultimately manifesting as an enhancement in the output current. Unlike the significant change in short-circuit current, Figure 1 (b) The open-circuit voltage exhibits relative stability within the tested frequency range. Although slight fluctuations may exist, its amplitude does not change drastically with increasing frequency. This is mainly attributed to the fact that the core determinants of the open-circuit voltage are the inherent charge density on the surface of the friction layer and the maximum distance during the contact separation process, which directly affects the capacitance change. When the maximum distance remains constant and the frequency variation range is limited (0.5-2.5 Hz), the influence of frequency is relatively small. Although the increased separation speed at high frequencies may lead to a slight decrease in effective capacitance, the amount of charge transferred in a single contact separation event accumulates and changes only to a limited extent in a short period of time, and the combined effect keeps Voc relatively stable. Figure 1 (c) The output charge shown remains relatively stable as the frequency increases. This further corroborates the conclusion that the amount of charge transferred in a single contact separation cycle is essentially independent of the operating frequency.

[0074] Figure 3 This relates to the effect of the frictional contact area on the TENG's output performance. It can be seen that, at a constant operating frequency, the output current amplitude of the TENG exhibits a clear positive correlation with its effective frictional contact area. As the contact area gradually increases, the output current amplitude shows a linear or near-linear growth characteristic. This pattern stems from the fact that a larger contact area can accommodate more surface charge points participating in the triboelectric and electrostatic induction processes. The expansion of the contact area directly increases the total charge generated during triboelectric charging. According to the definition of current (I = dQ / dt), under the condition that the contact separation speed (dz / dt or d(1 / C) / dt) remains constant, a larger change in charge (dQ) inevitably leads to a higher instantaneous current output. Therefore, Figure 2 This verifies that increasing the frictional contact area is one of the effective strategies to improve the output current power of the TENG.

[0075] Test Example 2 Durability and stability testing: After multiple cycles and washing tests, the output performance is stable and suitable for long-term wearable applications.

[0076] Test Example 3 Flexibility performance testing: The electrical output response of triboelectric nanogenerator was measured using a Keithley 6514 electrometer. Voltage output performance was tested after 100,000 mechanical deformations.

[0077] from Figure 3 As can be seen, the device exhibits excellent mechanical and electrical stability under repeated folding deformation. After 100,000 complete folding cycles, the output voltage remained stable at 1.6 V, with no statistically significant performance degradation compared to the initial state. The overlap of the 95% confidence intervals before and after folding further confirms the voltage stability. This excellent retention of electrical performance indicates that the device effectively mitigates the effects of mechanical stress through optimized design, such as the strain-distributed electrode structure and durable interface connections. This fully demonstrates the reliability of the device in applications requiring both flexibility and stable power output.

[0078] As can be seen from Table 1, the ratio of C3N5 to F-CNTs, the solid-liquid ratio, the calcination temperature, the curing time, and the solubility of the silver ammonia solution all affect the output electrical performance.

[0079] Table 1 shows the test output electrical performance. Voltage output (V) Voltage output (V) Example 1 1.64 Comparative Example 1 1.51 Example 2 1.63 Comparative Example 2 1.52 Example 3 1.62 Comparative Example 3 1.59 Example 4 1.64 Comparative Example 4 1.53 Example 5 1.62 Comparative Example 5 1.52 Example 6 1.63 Comparative Example 6 1.48 Example 7 1.62 Comparative Example 7 1.60 Example 8 1.59 Comparative Example 8 1.58 Example 9 1.60 Comparative Example 9 1.51 Example 10 1.62 Comparative Example 10 1.35 Example 11 1.64 Comparative Example 11 1.36 Example 12 1.61 Comparative Example 12 1.48 Example 13 1.64 Comparative Example 13 1.32 Example 14 1.64 Comparative Example 14 1.29 Example 15 1.62 Figure 4 The evolution of the electrical output performance of the triboelectric nanogenerator prepared in Example 1 under increasing pressures of 1–7 N is demonstrated, including short-circuit current, open-circuit voltage, and output charge. Experimental data clearly show that Isc, Voc, and Qsc all exhibit a significant and consistent increasing trend with increasing applied pressure. This performance improvement is mainly due to: firstly, the increased pressure significantly enhances the effective contact area between the triboelectric layers, prompting more micro-contact points to participate in the triboelectric process, thereby increasing the total amount of surface charge generated; secondly, the higher pressure forces the triboelectric material to undergo closer contact and deeper deformation, strengthening the charge transfer driving force at the interface and improving the efficiency of electron transfer from donor to acceptor. Finally, the pressure-induced close contact effectively reduces the interfacial contact resistance, optimizing the charge transfer path and separation efficiency during the contact separation process. These factors collectively determine the increase in surface charge density and the acceleration of charge transfer rate.

[0080] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A triboelectric nanogenerator, characterized in that: The triboelectric nanogenerator includes two PU / Ag / Cu composite positive electrode materials and one PDMS / C3N5 / F-CNTs composite negative electrode material, as well as a PTFE insulating layer disposed between the positive and negative electrodes. The PTFE insulating layer alternately stacks the two positive electrode materials and one negative electrode material to form a symmetrical sandwich structure of "positive electrode-PTFE-negative electrode-PTFE-positive electrode". The thickness of the PTFE insulating layer is 30-80 μm, and the ratio of the positive electrode layer area to the negative electrode layer area is (1.8-2.2):

1.

2. The triboelectric nanogenerator according to claim 1, characterized in that: The substrate of the PDMS / C3N5 / F-CNTs composite anode material is PDMS, in which C3N5 and F-CNTs are uniformly distributed. And / or, The PU / Ag / Cu composite cathode material has a coaxial three-layer structure, consisting of a high-purity copper core, a silver layer, and a polyurethane protective layer, from the core layer to the outer layer. The copper core has a diameter of 10-500 μm, the silver layer has a thickness of 50-200 nm, and the polyurethane protective layer has a thickness of 20-200 μm.

3. The triboelectric nanogenerator according to claim 2, characterized in that: The preparation method of the negative electrode material includes the following steps: S1. C3N5 nanosheets and F-CNTs were added to an isopropanol solution and dispersed uniformly by ultrasonic dispersion to obtain a mixed dispersion. The mixture was washed with ethanol and deionized water and filtered. After drying, it was ground into a uniform powder and then calcined at high temperature under argon protection to form a "pinned" interlocking structure between C3N5 nanosheets and F-CNTs. S2. The C3N5 / F-CNTs "pinned" interlocking structure powder obtained in step S1 is mixed with vinyl-terminated polydimethylsiloxane at a mass ratio. The powder is uniformly distributed in the vinyl-terminated polydimethylsiloxane by mechanical stirring and ultrasound. Then, a hydrogen-containing silicone oil crosslinking agent in proportion to the vinyl-terminated polydimethylsiloxane is added and mechanically stirred to form a mixture. S3. The mixture from step S2 is subjected to vacuum degassing treatment, then injected into a molding mold and placed in a temperature-controlled environment for heating and curing to form a base material.

4. The triboelectric nanogenerator according to claim 2, characterized in that: The method for preparing the cathode material includes the following steps: S11. After cleaning the copper wire, immerse it in silver ammonia solution containing temperature-sensitive polymer and glucose-PVP mixture in sequence. Through temperature-controlled gradient chemical plating process, a three-dimensional network structure silver plating layer is deposited on its surface. S12. The silver-plated copper wire from step S11 is immersed in a polyurethane / DMF mixed solution of a preset concentration to form a continuous polymer coating layer on its surface. Then, it undergoes preliminary drying and segmented temperature-controlled curing to obtain the positive electrode material.

5. The triboelectric nanogenerator according to claim 3, characterized in that: In step S1, the ultrasonic power is 250-400 W, the ultrasonic time is 30-90 min, the mass ratio of C3N5 nanosheets to CNTs-F is 1:0.5-1:2, the solid-liquid ratio of isopropanol to the mixed material is 1g:120-180 mL, the calcination temperature is 500-800℃, and the calcination time is 1-3 h.

6. The triboelectric nanogenerator according to claim 3, characterized in that: In step S2, the mass ratio of C3N5 / F-CNTs "pinned" interlocking structure powder to vinyl-terminated polydimethylsiloxane is 5:1-15:1, the mechanical stirring speed is 500-1000 r / min, the time is 30-120 min, and the ultrasonic dispersion time is 20-40 min; the mass ratio of vinyl-terminated polydimethylsiloxane to hydrogen-containing silicone oil crosslinking agent is 10:1, and the mechanical stirring speed is 300-600 r / min.

7. The triboelectric nanogenerator according to claim 3, characterized in that: In step S3, the vacuum degree of the vacuum degassing treatment is -0.08 to -0.10 MPa, the degassing time is 10-30 min, the heating and curing temperature is 60-100 ℃, and the time is 1-4 h.

8. The triboelectric nanogenerator according to claim 4, characterized in that: In step S11, the silver ion concentration of the silver ammonia solution is 0.1-0.5 mol / L, and the thermosensitive polymer is poly(N-isopropylacrylamide) with a concentration of 1-5 wt%; the glucose-PVP mixture has a glucose concentration of 0.3-0.7 mol / L, and polyvinylpyrrolidone has a molecular weight of 8000-50000 and a concentration of 0.1-0.5 mol / L; and / or, The gradient chemical plating process consists of three stages: the first stage is immersion at a low temperature of 5-15℃ for 10-30 min, the second stage is reaction at 25-35℃ for 20-40 min, and the third stage is high-temperature strengthening at 45-60℃ for 15-25 min.

9. The triboelectric nanogenerator according to claim 4, characterized in that: In step S12: the concentration of the polyurethane / DMF mixed solution is 10-30 wt%, and the impregnation time is 0.5-5 min; the preliminary drying treatment uses hot air drying at 50-70℃ for 3-15 min, with an air velocity of 2-5 m / s; and / or, The segmented temperature-controlled curing process includes: Stage 1: 40-60℃ constant temperature for 20-60 min; Stage 2: 70-90℃ constant temperature for 1-4 h; Stage 3: 100-120℃ constant temperature for 0.5-3 h; The heating rate between each stage is 0.5-3℃ / min.

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