A friction nanogenerator and a preparation method thereof
By designing ternary composite materials and a dynamic crosslinking system, the shortcomings of triboelectric nanogenerators in terms of materials and processes have been overcome, resulting in a triboelectric nanogenerator with high output performance and long lifespan, which is suitable for wearable electronics and industrial sensing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUZHOU UNIV
- Filing Date
- 2026-04-30
- Publication Date
- 2026-06-02
Smart Images
Figure CN122137261A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of triboelectric nanogenerator technology, and particularly relates to a triboelectric nanogenerator and its preparation method. Background Technology
[0002] Triboelectric nanogenerators (TENGs), based on the coupling effect of triboelectricity and electrostatic induction, can efficiently convert low-frequency, low-amplitude mechanical energy (such as human movement, wave vibration, and equipment vibration) into electrical energy. Due to their advantages such as simple structure, low cost, flexible material selection, and adaptability, they have become one of the core supporting technologies in distributed energy, self-powered systems, wearable electronics, self-driven sensing, and environmental energy harvesting. With the continuous expansion of TENG application scenarios, the industry has placed more stringent requirements on TENG output performance, structural stability, and service life. Among these, the material composite design of the triboelectric layer, the precision of surface patterning processes, and the self-healing capability have become key technological breakthroughs restricting performance improvement and application expansion.
[0003] The current industry's core demands for TENGs focus on three aspects: first, improving output performance, which requires balancing the charge separation efficiency and conductivity of the triboelectric layer to achieve efficient conversion of mechanical energy into electrical energy; second, optimizing structural durability to effectively address surface wear or microcracks caused by long-term friction, ensuring long-term stable operation of the device; and third, simplifying the fabrication process to achieve continuous and large-scale production of high-precision structures, lowering the threshold for industrial application. However, existing TENG technologies still have significant limitations in material system synergy, process design rationality, and performance stability, making it difficult to meet the practical application needs in complex scenarios.
[0004] From the perspective of triboelectric layer material design, existing solutions generally suffer from single functionality and insufficient synergy. For example, patent CN 113787797 A discloses a stretchable composite film of fatty acid %2FSEBS with enhanced triboelectric output, its preparation method and application. Although the triboelectric output performance of SEBS is improved to a certain extent through fatty acid modification, the lack of piezoelectric materials such as PVDF or highly conductive fillers such as MXene results in poor conductivity and low charge transport efficiency of the composite layer. Its output performance is only 3.28 times higher than that of pure SEBS, and it lacks anti-wear design, with an output attenuation of more than 40% after long-term use. Patent CN110411616 A discloses the fabrication of a flexible pressure sensor for monitoring motion signals and human pulse signals. It uses a PVDF / silver nanowire composite nanofiber membrane as the negative friction layer. Although the specific surface area of the material is increased by electrospinning, the silver nanowires are prone to agglomeration, which makes the charge separation efficiency only 40% higher than that of traditional thin films, making it difficult to break through the output performance bottleneck. At the same time, its positive friction layer uses ethyl cellulose material, which does not have self-healing function. Once microcracks appear on the surface, it loses the ability to generate triboelectric power.
[0005] At the level of process and structural optimization, existing technologies struggle to achieve a balance between precision and production efficiency. For example, patent CN114872416 A discloses a gradient elastic polyurethane, its preparation method, and its applications. This method prepares a PTFE-doped polyurethane elastomer through a foaming process. However, the foaming process suffers from low precision, with micron-level protrusions exhibiting size deviations exceeding 15%, and it cannot simultaneously construct a nanoscale fiber network, resulting in limited contact area at the friction interface. Furthermore, this process cannot achieve continuous production, with a capacity of only 0.5m³. 2 The current speed is insufficient to meet the needs of large-scale applications. Patent CN 110411616 A uses a traditional electrospinning process, which can only produce randomly distributed nanofiber membranes with a fiber orientation degree of less than 50%. This results in a disordered charge transport path along the friction direction, further limiting the improvement of output performance.
[0006] In terms of durability and environmental adaptability, existing TENGs generally lack effective self-healing mechanisms. None of the friction layers disclosed in the three patents mentioned above are designed with self-healing structures. Under long-term friction or external impact, microcracks easily form on the surface, leading to a decrease in frictional contact area and increased charge leakage. After 1000 cycles of use, the output performance decays by more than 50%. Currently, some electronic material technologies involving self-healing functions either require external stimuli such as temperatures above 60°C or specific pH environments to achieve repair, or can only repair electrical properties without restoring the material's mechanical strength. These technologies are difficult to adapt to practical application scenarios such as room temperature and complex humidity levels, which is inconsistent with the current development trend of room-temperature self-healing triboelectric materials.
[0007] Therefore, developing a triboelectric nanogenerator that combines a "high conductivity-high voltage" composite triboelectric layer, a precision gradient structure, and room temperature self-healing function has become an urgent problem to be solved. Summary of the Invention
[0008] To address the aforementioned technical problems, this invention provides a triboelectric nanogenerator and its preparation method.
[0009] The first objective of this invention is to provide a method for preparing a triboelectric nanogenerator, comprising the following steps: S1. Styrene-ethylene-butene-styrene block copolymer, polyvinylidene fluoride and MXene nanomaterials are dispersed in a mixed solvent and stirred evenly to obtain a negative friction layer spinning solution; S2. Using dynamic pattern-induced multi-material nanofiber electrospinning technology, the spinning solution of the negative friction layer described in S1 is deposited on the surface of the negative electrode to form a micro-nano structure, which is then dried to obtain the negative friction layer. The micro-nano structure includes an ordered nanofiber network arranged in a hexagonal pattern, and micron-level protrusions are formed in situ at the junctions of the nanofiber network. S3. Disperse thermoplastic starch, sodium carboxymethyl cellulose and plasticizer in water, stir magnetically until uniform, then add bis(2-hydroxyethyl) disulfide and dithiothreitol, heat and stir until uniform, and obtain positive friction layer film-forming liquid after degassing. S4. The positive friction layer film-forming liquid described in S3 is poured into a mold, and after standing, natural drying, demolding and vacuum drying, a positive friction layer is obtained; the mold is provided with a micro-nano structure that matches the negative friction layer; S5. The positive electrode is composited onto the side of the positive friction layer without micro / nano structure described in S4, so that the micro / nano structure surface of the positive friction layer is directly aligned with the micro / nano structure surface of the negative friction layer described in S2. The device is then sequentially positioned by an insulating frame, bonded and cured with wires, and sealed at the device edge to obtain the triboelectric nanogenerator.
[0010] In one embodiment of the present invention, in S1, the mass ratio of the styrene-ethylene-butene-styrene block copolymer to polyvinylidene fluoride is (3.4-11):1; And / or, the amount of MXene nanomaterial added is 2%-3.5% of the total mass of styrene-ethylene-butene-styrene block copolymer and polyvinylidene fluoride; And / or, the mixed solvent is obtained by mixing toluene and tetrahydrofuran in a volume ratio of (6-10):1.
[0011] In one embodiment of the present invention, in S1, the stirring temperature is 45℃-55℃ and the stirring speed is 380rpm-420rpm.
[0012] In one embodiment of the present invention, in S2, the process of the dynamic pattern-induced multi-material nanofiber electrospinning technology is as follows: the electric field strength is 1.1kV / cm-3.2kV / cm, the nozzle flow rate is 0.6mL / h-1.0mL / h, the receiving distance is 15cm-14cm, and the patterned collector rotation speed is 60r / min-200r / min.
[0013] In one embodiment of the present invention, in S2, the side length of the ordered nanofiber network structure is 25μm-30μm and the side width is 11.5μm-12.5μm; And / or, the height of the micron-sized protrusion is 5.5 μm-6.2 μm; And / or, the base thickness of the negative friction layer is 3μm-7μm; wherein, the base thickness does not include micron-level protrusions.
[0014] In one embodiment of the present invention, in S3, the thermoplastic starch is corn starch; And / or, the plasticizer is selected from one or more of glycerol, polyethylene glycol 400 and triethyl citrate; And / or, the crosslinking agent is selected from one or more of bis(2-hydroxyethyl) disulfide, dimethyl thiodipropionate, and cystamine dihydrochloride; And / or, the mass ratio of the thermoplastic starch, sodium carboxymethyl cellulose, plasticizer, crosslinking agent and dithiothreitol is 1:(0.02-0.025):(0.67-1.2):(0.03-0.067):(0.005-0.013); the mobility of polymer chain segments is improved by adjusting the amount of plasticizer, and the dynamic disulfide bond density and exchange catalytic efficiency are improved by adjusting the amount of crosslinking agent.
[0015] In one embodiment of the present invention, in S3, the magnetic stirring is performed at 450 r / min-500 r / min for 12 min-18 min; And / or, the heating and stirring is first stirred at 530r / min-570r / min for 9min-11min, and then stirred at 95℃-105℃ and 480r / min-520r / min for 20min-25min.
[0016] In one embodiment of the present invention, in S4, the settling time is 10 min to 20 min; And / or, the vacuum drying temperature is 40℃-45℃, and the time is 40min-60min.
[0017] In one embodiment of the present invention, in S4, the overall thickness of the positive friction layer is 78μm-90μm; wherein, the overall thickness includes micro-nano structures; this thickness range can prevent the movement of polymer chain segments from being restricted due to excessive thickness, thus affecting the self-healing performance, and can also avoid reducing the flexibility of the material due to excessive thickness. At the same time, the surface of the positive friction layer forms a groove structure that complements the micron-level protrusion array of the negative friction layer through mold morphology matching, which can further improve the effective contact area of the friction interface.
[0018] In one embodiment of the present invention, the negative electrode and the positive electrode are independently selected from copper foil, aluminum foil or ITO conductive glass.
[0019] A second objective of this invention is to provide a triboelectric nanogenerator prepared by the method described above.
[0020] The technical solution of the present invention has the following advantages compared with the prior art: (1) The preparation method described in this invention uses a ternary composite system composed of styrene-ethylene-butene-styrene block copolymer, polyvinylidene fluoride and MXene nanomaterials. Through dynamic pattern-induced multi-material nanofiber electrospinning technology, a negative friction layer with micro-nano structure is prepared. This micro-nano structure relies on the high space filling rate of hexagonal arrangement to maximize the friction unit per unit area. Combined with the high specific surface area characteristics of nanofibers, it significantly increases the friction contact area and improves the charge separation efficiency, thereby greatly improving the triboelectric charge density and output power density of the device.
[0021] (2) The preparation method described in this invention uses thermoplastic starch as the main body, introduces sodium carboxymethyl cellulose, a crosslinking agent containing disulfide bonds and dithiothreitol, utilizes the carboxyl group of sodium carboxymethyl cellulose and the hydroxyl group of thermoplastic starch to construct a first dynamic hydrogen bond physical network, and constructs a second dynamic covalent network by inducing a dynamic exchange reaction of disulfide bonds through dithiothreitol, forming a double dynamic crosslinking system, which endows the positive friction layer with room temperature self-healing ability.
[0022] (3) The positive and negative friction layers of the triboelectric nanogenerator described in this invention can move relative to each other in a direction parallel to the interlayer contact surface, and generate electrical signals by relying on the coupling effect of triboelectric charging and electrostatic induction; wherein the positive friction layer constructs a dual dynamic cross-linking system of hydrogen bonds and disulfide bonds, achieving a highly efficient room temperature self-healing effect, and the self-healing core component does not interfere with the triboelectric power generation process, realizing the compatibility of self-healing function and high output performance. At the same time, the positive and negative friction layers of the device adopt a micro-nano structure design with matching concave and convex features, which greatly improves the cycle durability. After 10,000 cycles of friction, the open circuit voltage and short circuit current decay rate are both at a low level, and the hardness decay rate is also low. After the device has undergone 10,000 cycles, it is left to stand at room temperature for 24 hours, and the recovery rate of its open circuit voltage, short circuit current and hardness all exceed 92%.
[0023] (4) The biomimetic multi-level structure of the negative friction layer of the triboelectric nanogenerator described in this invention is induced and formed by a hexagonal discrete conductive pattern. Its core advantages are: the hexagonal arrangement makes the structure uniformly stressed and the friction interface contact stable; the micron-level protrusions at the network junctions can significantly increase the effective contact area of the friction interface; the ordered hexagonal nanofibers provide stiffness support for the micron-level protrusions; and at the same time, relying on the flexible adaptation of the nanofibers to the micro-deformation of the interface, it effectively disperses stress, inhibits crack initiation, and greatly improves the fatigue resistance and wear resistance of the structure.
[0024] (5) The preparation method described in this invention adopts dynamic pattern-induced multi-material nanofiber electrospinning technology, which can accurately realize the integrated molding of multi-level micro-nano structures induced by hexagonal conductive patterns. It can accurately control the size, arrangement and bonding degree of micron-level protrusion array and nano-level ordered fibers, ensuring the orderliness and consistency of micro-nano structures. This process is both efficient and controllable. It can directly deposit the negative friction layer spinning solution on the electrode layer surface to achieve a tight bond between the micro-nano structure and the electrode substrate without secondary processing. At the same time, it can take into account the mechanical integrity of the negative friction layer and the adaptability of the friction interface, greatly improving the preparation accuracy of micro-nano structures and the performance stability of finished devices.
[0025] (6) The preparation method described in this invention takes into account both the ease of preparation and the need for large-scale production. The device produced has high output, long life and flexibility, and can be adapted to various scenarios such as wearable electronics, industrial high temperature sensing and environmental mechanical energy harvesting. Attached Figure Description
[0026] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a schematic diagram of the nanofiber network structure in the negative friction layer of the present invention; Figure 2 This is a schematic diagram of the protrusion structure in the negative friction layer of the present invention. Detailed Implementation
[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.
[0028] In this invention, unless otherwise stated, the styrene-ethylene-butene-styrene block copolymer used in the examples was purchased from Kraton, model Kraton G1650; polyvinylidene fluoride was purchased from Arkema; corn starch was purchased from Suzhou Wuyi Chemical Technology Co., Ltd.; sodium carboxymethyl cellulose and conductive silver paste were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; PDMS-based adhesive and curing agent were silicone elastomer kits purchased from Dow Chemical; and PI tape was Tesa 66320.
[0029] In this invention, unless otherwise stated, the thickness of the copper foil used in the embodiments is 30 μm.
[0030] In this invention, unless otherwise stated, the Ti3C2T used in the embodiments is... x The preparation method of MXene nanomaterials includes the following steps: Ti3AlC2 MAX phase powder is added to a 25wt% hydrofluoric acid solution, and etched by magnetic stirring at room temperature for 36 hours; after etching, the mixture is centrifuged at 10000 rpm for 5 minutes, the supernatant is discarded, and the precipitate is repeatedly washed with deionized water and centrifuged until the pH of the system is approximately 5.5; the obtained multilayer Ti3C2T... x Dispersed in deionized water, the layers were exfoliated by sonication at 200W for 45 minutes. The exfoliated dispersion was then centrifuged at 4000rpm, and the supernatant was vacuum dried.
[0031] Example 1
[0032] The triboelectric nanogenerator and its preparation method in this embodiment specifically include the following steps: S1, Preparation of the negative friction layer S11. Preparation of the negative friction layer spinning solution: 1.8g of styrene-ethylene-butene-styrene block copolymer and 0.2g of polyvinylidene fluoride were dissolved together in a mixed solvent of 18mL toluene and 2mL tetrahydrofuran. The mixture was stirred continuously at 50℃ and 400rpm for 24h. Then, 2% of Ti3C2T by mass of the polymer matrix was added. x MXene nanomaterials were mixed evenly to obtain a negative friction layer spinning solution; S12. Preparation of the negative friction layer: Using dynamic pattern-induced multi-material nanofiber electrospinning technology, under the process conditions of an electric field strength of 1.1 kV / cm, a nozzle flow rate of 0.6 mL / h, a receiving distance of 15 cm, and a patterned collector rotation speed of 200 r / min, the negative friction layer spinning solution was precisely deposited on the surface of a copper foil electrode, forming an ordered nanofiber network structure with a fiber diameter of 400 nm and a hexagonal arrangement (side length a is 25 μm, side width b is 11.5 μm). Figure 1 ), and in situ constructed micron-sized protrusions with a height of 5.5 μm at the fiber network junctions ( Figure 2 The sample was then placed on a clean bench, and the back and edges of the copper foil electrode were wiped with a clean paper dipped in a small amount of anhydrous ethanol. After being dried with a cold air setting, it was vacuum dried at 40°C for 30 minutes to obtain a negative friction layer with a base thickness of 7μm. S2, Preparation of the positive friction layer S21. Preparation of positive friction layer film-forming solution: At room temperature, 100 mL of deionized water was added to 15 g of corn starch and 0.3 g of sodium carboxymethyl cellulose, and a stir bar was placed in the solution. The mixture was magnetically stirred at 450 r / min for 10 min. Then, 10.0 mL of glycerol was added dropwise and stirring was continued for 5 min. Next, 0.45 g of bis(2-hydroxyethyl) disulfide and 0.075 g of dithiothreitol were added. The stirring speed was adjusted to 550 r / min and stirring was continued for 10 min. Finally, the mixture was placed on a 100℃ heating platform and magnetically stirred at 500 r / min for 20 min. The mixture was then degassed under a vacuum of -0.09 MPa for 15 min to obtain the positive friction layer film-forming solution. S22. Preparation of the positive friction layer: The positive friction layer film-forming liquid is poured into a mold with a microstructure that matches the negative friction layer. During the pouring process, the mold is gently shaken to remove the internal micro air bubbles. Then, the mold is placed on a horizontal platform and left to stand for 5 minutes. Then, it is transferred to a constant temperature and humidity environment of 25°C and 45% and allowed to dry naturally for 72 hours. After demolding, it is then vacuum dried at 40°C for 40 minutes to obtain a positive friction layer with a surface micro-nano structure that matches the negative friction layer and an overall thickness of 80 μm. Finally, a copper foil electrode is composited on the side of the positive friction layer without the micro-nano structure.
[0033] S3. Preparation of triboelectric nanogenerators First, sand one end of a 0.1mm diameter copper wire with 800-grit sandpaper for 5mm until the metal is exposed. Then, evenly apply 60% solids conductive silver paste and set aside. Take a 20μm thick insulating PI tape and attach a closed border around the edges of the copper foil substrate of the negative friction layer, maintaining a 1.5mm gap between the inner side of the tape and the edge of the negative friction layer. Align the micro / nano structure surfaces of the positive friction layer and the negative friction layer, and slowly cover the PI tape border. Gently press from the center outwards to expel tiny air bubbles from the gaps. Let it stand for 10 minutes at 25℃ and 45% relative humidity to ensure full adhesion between the positive friction layer and the PI tape and prevent interlayer misalignment. Then… Coated copper wires were attached to the lead-out ends of the negative friction layer copper foil, and lightly pressed and fixed with insulating silicone clamps without applying additional force. The device was then placed in a ventilated and dust-free environment and allowed to cure for 2 hours. The same method was used to attach and cure the wires of the positive friction layer copper foil electrode. PDMS base adhesive and curing agent were mixed at a mass ratio of 10:1 and vacuumed for 10 minutes to remove bubbles, resulting in a PDMS sealant with a viscosity of approximately 2000 cSt. The sealant was applied along the edge gaps of the device using a micro-dispensing pen with a capillary leveling method, controlling the sealant thickness to approximately 20 μm. Finally, the device was placed on a 25°C, ventilated and dust-free horizontal platform and allowed to stand for 24 hours until the PDMS sealant was completely cured, thus obtaining a triboelectric nanogenerator.
[0034] Example 2
[0035] The triboelectric nanogenerator and its preparation method in this embodiment specifically include the following steps: S1, Preparation of the negative friction layer S11. Preparation of the negative friction layer spinning solution: 1.7g of styrene-ethylene-butene-styrene block copolymer and 0.5g of polyvinylidene fluoride were dissolved together in a mixed solvent of 18mL toluene and 3mL tetrahydrofuran. The mixture was stirred continuously at 50℃ and 400rpm for 24h. Then, 3.5% of Ti3C2T by mass of the polymer matrix was added. x MXene nanomaterials were mixed evenly to obtain a negative friction layer spinning solution; S12. Preparation of the negative friction layer: Using dynamic pattern-induced multi-material nanofiber electrospinning technology, under the process conditions of an electric field strength of 3.2 kV / cm, a nozzle flow rate of 0.95 mL / h, a receiving distance of 14 cm, and a patterned collector rotation speed of 60 r / min, the negative friction layer spinning solution was precisely deposited on the surface of a copper foil electrode, forming an ordered nanofiber network structure with a fiber diameter of 400 nm and a hexagonal arrangement (side length a is 26 μm, side width b is 11.8 μm). Figure 1 ), and in situ constructed micron-sized protrusions with a height of 6.2 μm at the fiber network junctions ( Figure 2 The sample was then placed on a clean bench, and the back and edges of the copper foil electrode were wiped with a clean paper dampened with a small amount of anhydrous ethanol. After being dried with a cold air setting, it was vacuum dried at 45°C for 30 minutes to obtain a negative friction layer with a base thickness of 3.5 μm. S2, Preparation of the positive friction layer S21. Preparation of positive friction layer film-forming solution: At room temperature, 100 mL of deionized water was added to 16 g of corn starch and 0.4 g of sodium carboxymethyl cellulose, and a stir bar was placed in the solution. The mixture was magnetically stirred at 500 r / min for 10 min. Then, 12.0 mL of glycerol was added dropwise and stirring was continued for 5 min. Next, 0.6 g of bis(2-hydroxyethyl) disulfide and 0.12 g of dithiothreitol were added. The stirring speed was adjusted to 550 r / min and stirring was continued for 10 min. Finally, the mixture was placed on a 105℃ heating platform and magnetically stirred at 500 r / min for 25 min. The mixture was then degassed under a vacuum of -0.09 MPa for 15 min to obtain the positive friction layer film-forming solution. S22. Preparation of the positive friction layer: The positive friction layer film-forming liquid is poured into a mold with a microstructure that matches the negative friction layer. During the pouring process, the mold is gently shaken to remove the internal micro air bubbles. Then, the mold is placed on a horizontal platform and left to stand for 5 minutes. Then, it is transferred to a constant temperature and humidity environment of 25°C and 45% and allowed to dry naturally for 72 hours. After demolding, it is then vacuum dried at 45°C for 40 minutes to obtain a positive friction layer with a surface micro-nano structure that matches the negative friction layer and an overall thickness of 78 μm. Finally, a copper foil electrode is composited on the side of the positive friction layer without the micro-nano structure.
[0036] S3. The preparation of the triboelectric nanogenerator is the same as in Example 1.
[0037] Example 3
[0038] The triboelectric nanogenerator and its preparation method in this embodiment specifically include the following steps: S1, Preparation of the negative friction layer S11. Preparation of the negative friction layer spinning solution: 2.2g of styrene-ethylene-butene-styrene block copolymer and 0.2g of polyvinylidene fluoride were dissolved together in a mixed solvent of 20mL toluene and 2mL tetrahydrofuran. The mixture was stirred continuously at 50℃ and 400rpm for 24h. Then, 3.0% of Ti3C2T by mass of the total polymer matrix was added. x MXene nanomaterials were mixed evenly to obtain a negative friction layer spinning solution; S12. Preparation of the negative friction layer: Using dynamic pattern-induced multi-material nanofiber electrospinning technology, under the process conditions of an electric field strength of 3.0 kV / cm, a nozzle flow rate of 1.0 mL / h, a receiving distance of 15 cm, and a patterned collector rotation speed of 60 r / min, the negative friction layer spinning solution was precisely deposited on the surface of a copper foil electrode, forming an ordered nanofiber network structure with a fiber diameter of 400 nm and a hexagonal arrangement (side length a is 30 μm, side width b is 12.5 μm). Figure 1 ), and in situ constructed micron-sized protrusions with a height of 6.0 μm at the fiber network junctions ( Figure 2 The sample was then placed on a clean bench, and the back and edges of the copper foil electrode were wiped with a clean paper dipped in a small amount of anhydrous ethanol. After being dried with a cold air setting, it was vacuum dried at 40°C for 30 minutes to obtain a negative friction layer with a base thickness of 3μm. S2, Preparation of the positive friction layer S21. Preparation of positive friction layer film-forming solution: At room temperature, 100 mL of deionized water was added to 15 g of corn starch and 0.3 g of sodium carboxymethyl cellulose, and a stir bar was placed in the solution. The mixture was magnetically stirred at 450 r / min for 10 min. Then, 18.0 mL of glycerol was added dropwise and stirring was continued for 5 min. Next, 1.0 g of bis(2-hydroxyethyl) disulfide and 0.2 g of dithiothreitol were added. The stirring speed was adjusted to 550 r / min and stirring was continued for 10 min. Finally, the mixture was placed on a 100℃ heating platform and magnetically stirred at 500 r / min for 25 min. The mixture was then degassed under a vacuum of -0.09 MPa for 15 min to obtain the positive friction layer film-forming solution. S22. Preparation of the positive friction layer: The positive friction layer film-forming liquid is poured into a mold with a microstructure that matches the negative friction layer. During the pouring process, the mold is gently shaken to remove the internal micro air bubbles. Then, the mold is placed on a horizontal platform and left to stand for 5 minutes. Then, it is transferred to a constant temperature and humidity environment of 25°C and 45% and allowed to dry naturally for 72 hours. After demolding, it is then vacuum dried at 40°C for 1 hour to obtain a positive friction layer with a surface micro-nano structure that matches the negative friction layer and an overall thickness of 90 μm. Finally, a copper foil electrode is composited on the side of the positive friction layer without the micro-nano structure.
[0039] S3. The preparation of the triboelectric nanogenerator is the same as in Example 1.
[0040] Comparative Example 1
[0041] It is basically the same as Example 1, except that: micron-level protrusions are not constructed in situ at the fiber network junctions.
[0042] Comparative Example 2
[0043] Basically the same as Example 1, except that Ti3C2T was not added. x MXene nanomaterials.
[0044] Comparative Example 3
[0045] The basic formula is the same as in Example 1, except that dithiothreitol was not added.
[0046] Comparative Example 4
[0047] It is basically the same as Example 1, except that the positive friction layer has a flat structure.
[0048] Test Example 1
[0049] The performance of the triboelectric nanogenerators prepared in the examples and comparative examples was tested in accordance with GB / T 45525.1-2025 Nanotechnology Nanogenerators Part 1: Terminology and GB / T 45525.2-2025 Nanotechnology Nanogenerators Part 2: Test Methods for Electrical Performance of Triboelectric Nanogenerators. The results are shown in Tables 1-3. Table 1. Test results of the output electrical performance of the triboelectric nanogenerator under vibration conditions of 25℃, 45% RH, and 3Hz.
[0050] As can be seen from Table 1, the open-circuit voltage, short-circuit current and maximum output power density of Examples 1-3 are significantly higher than those of Comparative Examples 1-4, indicating that the present invention can significantly improve the electrical output performance of triboelectric nanogenerators through the synergistic design of highly conductive filler composite, gradient micro-nano structure construction, concave-convex interface matching and dynamic cross-linking self-healing system.
[0051] Comparing Example 1 and Comparative Example 1, it can be seen that the electrical performance of Comparative Example 1, which does not have micron-level protrusions, is significantly reduced. The open-circuit voltage, short-circuit current, and maximum output power density are only about 50% of those of Example 1. This proves that micron-level protrusions can significantly increase the effective contact area of the friction interface and enhance charge separation efficiency, making it a key structural design for improving output performance.
[0052] Comparing Example 1 and Comparative Example 2, it can be seen that without the addition of Ti3C2T x Comparative Example 2 of MXene showed the most significant decrease in electrical performance, with all three indicators decreasing by more than 60% compared to Example 1, indicating that Ti3C2T x MXene, with its high conductivity, optimizes charge transport and reduces charge loss, making it the core filler for realizing the "high conductivity-high voltage" composite negative friction layer.
[0053] Comparing Example 1 and Comparative Example 3, it can be seen that the electrical properties of Comparative Example 3 without the addition of dithiothreitol are basically the same as those of Example 1. This indicates that dithiothreitol only participates in the construction of the self-healing network of the positive friction layer and does not interfere with the triboelectric charging and electrostatic induction process, thus achieving compatibility between self-healing function and high output performance.
[0054] Comparing Example 1 and Comparative Example 4, it can be seen that the electrical performance of Comparative Example 4, which has a flat positive friction layer, is significantly reduced. The three indicators are reduced by about 40%-50% compared with Example 1, proving that the microstructure with matching concave and convex surfaces of the positive and negative friction layers can achieve all-round adhesion, further improving the interface contact efficiency and charge output.
[0055] Table 2. Test results of the attenuation rate of the triboelectric nanogenerator after 10,000 cycles.
[0056] Table 3. Results of the recovery rate test of the triboelectric nanogenerator after 10,000 cycles and 24 hours of rest at room temperature.
[0057] As can be seen from Tables 2 and 3, the open-circuit voltage, short-circuit current and hardness decay rate of the embodiment are extremely low after 10,000 cycles, and the recovery rate of each performance after standing at room temperature for 24 hours is over 92%, demonstrating excellent cycle durability and room temperature self-healing ability.
[0058] Comparing Example 1 and Comparative Example 1, it can be seen that the performance degradation rate of Comparative Example 1 without the construction of micron-level protrusions increased significantly and the recovery rate was extremely low after cycling. This proves that the ordered nanofiber network and micron-level protrusion structure can effectively disperse stress and inhibit crack initiation, which is the key to improving the wear resistance and structural stability of the device.
[0059] Comparing Example 1 and Comparative Example 2, it can be seen that Comparative Example 2, which did not add MXene nanomaterials, experienced the most severe performance degradation after cycling and had almost no repair capability. This indicates that MXene can significantly enhance the mechanical strength and conductivity of the negative friction layer, reduce friction wear and charge loss, and is the core filler to ensure long-term stable output of the device.
[0060] Comparing Example 1 and Comparative Example 3, it can be seen that the cycle durability of Comparative Example 3 without the addition of dithiothreitol is similar to that of Example 1, but the room temperature self-healing ability is significantly reduced, which confirms that dithiothreitol is a necessary component for constructing a dynamic disulfide bond network and achieving room temperature self-healing.
[0061] Comparing Example 1 and Comparative Example 4, it can be seen that Comparative Example 4, which uses a flat structure for the positive friction layer, has a high attenuation rate and poor repair effect after cycling due to insufficient interface contact and uneven stress distribution. This indicates that the complementary microstructure of concave and convex surfaces is crucial for maintaining the contact area and improving durability.
[0062] 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 method for preparing a triboelectric nanogenerator, characterized in that, Includes the following steps: S1. Styrene-ethylene-butene-styrene block copolymer, polyvinylidene fluoride and MXene nanomaterials are dispersed in a mixed solvent and stirred evenly to obtain a negative friction layer spinning solution; S2. Using dynamic pattern-induced multi-material nanofiber electrospinning technology, the spinning solution of the negative friction layer described in S1 is deposited on the surface of the negative electrode to form a micro-nano structure, which is then dried to obtain the negative friction layer. The micro-nano structure includes an ordered nanofiber network arranged in a hexagonal pattern, and micron-level protrusions are formed in situ at the junctions of the nanofiber network. S3. Disperse thermoplastic starch, sodium carboxymethyl cellulose and plasticizer in water, stir magnetically until uniform, then add bis(2-hydroxyethyl) disulfide and dithiothreitol, heat and stir until uniform, and obtain positive friction layer film-forming liquid after degassing. S4. The positive friction layer film-forming liquid described in S3 is poured into a mold, and after standing, natural drying, demolding and vacuum drying, a positive friction layer is obtained; the mold is provided with a micro-nano structure that matches the negative friction layer; S5. The positive electrode is composited onto the side of the positive friction layer without micro / nano structure described in S4, so that the micro / nano structure surface of the positive friction layer is directly aligned with the micro / nano structure surface of the negative friction layer described in S2. The device is then sequentially positioned by an insulating frame, bonded and cured with wires, and sealed at the device edge to obtain the triboelectric nanogenerator.
2. The method for preparing the triboelectric nanogenerator according to claim 1, characterized in that, In S1, the mass ratio of the styrene-ethylene-butene-styrene block copolymer to polyvinylidene fluoride is (3.4-11):1; And / or, the amount of MXene nanomaterial added is 2%-3.5% of the total mass of styrene-ethylene-butene-styrene block copolymer and polyvinylidene fluoride; And / or, the mixed solvent is obtained by mixing toluene and tetrahydrofuran in a volume ratio of (6-10):
1.
3. The method for preparing the triboelectric nanogenerator according to claim 1, characterized in that, In S1, the stirring temperature is 45℃-55℃ and the stirring speed is 380rpm-420rpm.
4. The method for preparing the triboelectric nanogenerator according to claim 1, characterized in that, In S2, the process of the dynamic pattern-induced multi-material nanofiber electrospinning technology is as follows: the electric field strength is 1.1kV / cm-3.2kV / cm, the nozzle flow rate is 0.6mL / h-1.0mL / h, the receiving distance is 15cm-14cm, and the patterned collector rotation speed is 60r / min-200r / min.
5. The method for preparing the triboelectric nanogenerator according to claim 1, characterized in that, In S2, the side length of the ordered nanofiber network structure is 25μm-30μm, and the side width is 11.5μm-12.5μm; And / or, the height of the micron-sized protrusion is 5.5 μm-6.2 μm; And / or, the base thickness of the negative friction layer is 3μm-7μm.
6. The method for preparing the triboelectric nanogenerator according to claim 1, characterized in that, In S3, the thermoplastic starch is corn starch; And / or, the plasticizer is selected from one or more of glycerol, polyethylene glycol 400 and triethyl citrate; And / or, the crosslinking agent is selected from one or more of bis(2-hydroxyethyl) disulfide, dimethyl thiodipropionate, and cystamine dihydrochloride; And / or, the mass ratio of the thermoplastic starch, sodium carboxymethyl cellulose, plasticizer, crosslinking agent and dithiothreitol is 1:(0.02-0.025):(0.67-1.2):(0.03-0.067):(0.005-0.013).
7. The method for preparing a triboelectric nanogenerator according to claim 1, characterized in that, In S3, the magnetic stirring is performed at 450 r / min-500 r / min for 12 min-18 min; And / or, the heating and stirring is first stirred at 530r / min-570r / min for 9min-11min, and then stirred at 95℃-105℃ and 480r / min-520r / min for 20min-25min.
8. The method for preparing a triboelectric nanogenerator according to claim 1, characterized in that, In S4, the settling time is 10 min to 20 min; And / or, the vacuum drying temperature is 40℃-45℃, and the time is 40min-60min.
9. The method for preparing a triboelectric nanogenerator according to claim 1, characterized in that, In S4, the overall thickness of the positive friction layer is 78μm-90μm.
10. A triboelectric nanogenerator prepared by the method according to any one of claims 1-9.