A high-output friction nanogenerator with double friction layers and a preparation method thereof

Abstract

The application discloses a kind of double friction layer synergic high output friction nanogenerator and preparation method thereof, method: preparation ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension;Respectively, ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film are made;After ferromagnetic nanoparticle / polyvinyl alcohol composite film and positive friction layer electrode, ferromagnetic nanoparticle / polyvinylidene fluoride composite film and negative friction layer electrode are combined, positive friction layer electrode and negative friction layer electrode are connected by external circuit, and double friction layer synergic high output friction nanogenerator is obtained.The application utilizes ferromagnetic nanoparticle to simultaneously control positive friction layer and negative friction layer, improves the electron transfer of friction layer surface and the electron trap inside friction layer, reduces charge recombination rate, and then greatly improves the output performance of friction nanogenerator, and has good application prospect.

Description

Technical Field

[0001] This invention relates to the field of nanoenergy and triboelectric nanogenerator technology, and specifically to a high-output triboelectric nanogenerator with dual triboelectric layers and its preparation method. Background Technology

[0002] Developing clean and sustainable power generation technologies is crucial for achieving carbon neutrality. Triboelectric nanogenerators (TNGs) show promise for clean energy harvesting due to their light weight, low cost, and simple structure; however, their low surface charge density limits further efficient utilization of clean energy. Recently, Yang et al. reported a contact-separated triboelectric nanogenerator operating at 525 μC / m² in an atmospheric environment. 2 A record-high charge density of 4.86 W / m was achieved. 2 The peak power density. Nevertheless, the increase in surface charge density is insufficient to meet the power requirements of electronic devices.

[0003] The primary factor influencing the surface charge density of triboelectric nanogenerators is charge recombination between the triboelectric layer and the electrode. As the two triboelectric layers come into contact, the presence of charge donor or acceptor regions on the surface of each layer causes electrons or holes to recombine with the positively or negatively charged surface, leading to charge recombination at the interface between the two triboelectric layers. Furthermore, when the triboelectric layer interface separates, a large electric field is generated between the surface charge of the triboelectric layer and the induced charge on the electrode, resulting in an electron concentration gradient from the interface to the interior of the triboelectric layer. Some electrons or holes can drift within the triboelectric layer and recombine with the positive or negative charges induced on the electrode. Therefore, not all surface charges generated by triboelectricity will induce charges on the electrode, which significantly reduces the output of the triboelectric nanogenerator.

[0004] Therefore, developing a triboelectric nanogenerator that can reduce charge recombination in the triboelectric layer to improve the output power of the triboelectric nanogenerator is of great practical significance. Summary of the Invention

[0005] Due to the aforementioned defects in the existing technology, the present invention provides a triboelectric nanogenerator and its preparation method that can reduce the charge recombination of the triboelectric layer to improve the output power of the triboelectric nanogenerator. Specifically, it is a high-output triboelectric nanogenerator with dual triboelectric layers working together, which overcomes the defect of limited output power of existing triboelectric nanogenerators.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A high-output triboelectric nanogenerator with dual friction layers includes a positive friction layer containing ferromagnetic nanoparticles, a negative friction layer containing ferromagnetic nanoparticles, a positive friction layer electrode, a negative friction layer electrode, and an external circuit.

[0008] The positive friction layer is attached to the positive friction layer electrode, and the negative friction layer is attached to the negative friction layer electrode. The positive friction layer electrode and the negative friction layer electrode are connected through an external circuit and are arranged opposite to each other.

[0009] The high-output triboelectric nanogenerator of the present invention incorporates ferromagnetic nanoparticles into both the positive and negative triboelectric layers, which can reduce the charge recombination rate and improve the output performance of the triboelectric nanogenerator. In addition, the ferromagnetic nanoparticles simultaneously regulate both the positive and negative triboelectric layers, thereby achieving a synergistic effect between the two triboelectric layers to improve the output performance of the triboelectric nanogenerator.

[0010] As a preferred technical solution:

[0011] The high-output triboelectric nanogenerator described above, with both the positive and negative triboelectric layers loaded with ferromagnetic nanoparticles.

[0012] The high-output triboelectric nanogenerator with dual friction layers as described above has a positive friction layer containing ferromagnetic nanoparticles that is a ferromagnetic nanoparticle / polyvinyl alcohol composite film, and a negative friction layer containing ferromagnetic nanoparticles that is a ferromagnetic nanoparticle / polyvinylidene fluoride composite film.

[0013] This invention also provides a method for preparing a high-output triboelectric nanogenerator with dual friction layers, comprising the following steps:

[0014] (1) Prepare ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension;

[0015] (2) Ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension were respectively made into ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film.

[0016] (3) After combining the ferromagnetic nanoparticle / polyvinyl alcohol composite film with the positive friction layer electrode and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film with the negative friction layer electrode, the positive friction layer electrode and the negative friction layer electrode are connected by an external circuit to obtain a high-output triboelectric nanogenerator with dual friction layers.

[0017] This invention utilizes ferromagnetic nanoparticles to reduce charge recombination rate, thereby improving the output performance of triboelectric nanogenerators; the ferromagnetic nanoparticles simultaneously modulate the positive and negative friction layers, achieving a synergistic improvement in the output performance of the triboelectric nanogenerator through the dual friction layers.

[0018] The above-mentioned method for preparing a high-output triboelectric nanogenerator with synergistic dual-friction layers is simple in steps, has relatively mild process conditions, is low in cost, and has good application prospects.

[0019] As a preferred technical solution:

[0020] The preparation method of the ferromagnetic nanoparticle / polyvinyl alcohol suspension for the high-output triboelectric nanogenerator with dual friction layers as described above is as follows:

[0021] Polyvinyl alcohol and water are mixed, heated, and stirred to dissolve to obtain a polyvinyl alcohol aqueous solution. Ferromagnetic nanoparticles are then added to the polyvinyl alcohol aqueous solution, and ultrasonic treatment and mechanical stirring are performed for 1-2 hours to obtain a ferromagnetic nanoparticle / polyvinyl alcohol suspension.

[0022] The method for preparing a high-output triboelectric nanogenerator with dual friction layers as described above, wherein the polyvinyl alcohol in the aqueous solution has a mass fraction of 5-10 wt%, the heating temperature is 70-100℃, and the dissolution time is 1-3 h;

[0023] The ferromagnetic nanoparticles have a particle size of 200–300 nm;

[0024] The mass fraction of the ferromagnetic nanoparticles in the ferromagnetic nanoparticle / polyvinyl alcohol suspension is 0.01–14 wt%.

[0025] The polyvinyl alcohol mentioned above is a conventional polyvinyl alcohol commonly used in the field. It is not specifically limited in this invention. Any polyvinyl alcohol particles that can achieve the present invention can be used. Aladdin polyvinyl alcohol 1788 type with a degree of alcoholysis of 87.0 to 89.0% (mol / mol) is preferred in this invention.

[0026] The preparation method of the high-output triboelectric nanogenerator with dual friction layers as described above, wherein the ferromagnetic nanoparticle / polyvinylidene fluoride suspension is prepared as follows:

[0027] An N,N-dimethylformamide (DMF) / acetone solution was prepared by mixing an N,N-dimethylformamide (DMF) solution and an acetone solution. Polyvinylidene fluoride (PVDF) was added to the N,N-dimethylformamide (DMF) / acetone solution and heated and stirred to dissolve, thus obtaining a PVDF solution. Ferromagnetic nanoparticles were added to the PVDF solution, ultrasonically treated, and mechanically stirred for 1–2 hours to obtain a ferromagnetic nanoparticle / PVDF suspension.

[0028] In the preparation method of the high-output triboelectric nanogenerator with dual friction layers as described above, the mass ratio of N,N-dimethylformamide to acetone in the N,N-dimethylformamide / acetone solution is 4:3 to 2:1.

[0029] The mass fraction of polyvinylidene fluoride in the polyvinylidene fluoride solution is 10-20 wt%.

[0030] The heating temperature is 70–100°C, and the heating and stirring time is 0.5–1 hour.

[0031] The ferromagnetic nanoparticles have a particle size of 200–300 nm; the mass fraction of the ferromagnetic nanoparticles in the ferromagnetic nanoparticle / polyvinylidene fluoride suspension is 0.01–10 wt%.

[0032] The polyvinylidene fluoride, N,N-dimethylformamide (DMF), and acetone mentioned above are commonly used conventional reagents in the field and are not specifically limited in this invention. Polyvinylidene fluoride particles, DMF, and acetone can all be used to achieve the present invention. The present invention preferably uses Aladdin's polyvinylidene fluoride (Mw=534000), Shanghai Taikang's DMF, and Guangzhou Chemical Reagent Factory's acetone.

[0033] The preparation method of the high-output triboelectric nanogenerator with dual friction layers as described above, wherein the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film are prepared by electrospinning technology.

[0034] The preparation method of the high-output triboelectric nanogenerator with dual friction layers as described above, wherein the preparation methods of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film are as follows:

[0035] 10 mL of ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension were drawn into a syringe and collected on a roller collector of an electrospinning device for 8–10 hours to obtain ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film.

[0036] In the method for fabricating a high-output triboelectric nanogenerator with dual friction layers as described above, the low voltage of the electrospinning equipment is set to -2 to -4 kV, the high voltage is set to 7 to 10 kV, and the injection rate of the syringe is 0.5 to 1.5 mm·min. -1 .

[0037] The preparation method of the high-output triboelectric nanogenerator with dual friction layers as described above, specifically step (3) is as follows:

[0038] A certain area of ​​ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film are cut. A positive friction layer electrode is attached to one side of the ferromagnetic nanoparticle / polyvinyl alcohol composite film, and a negative friction layer electrode is attached to the ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Wires are led out from the positive and negative friction layer electrodes and connected to an external circuit as signal output terminals. The ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film are arranged opposite to each other to obtain a high-output triboelectric nanogenerator with dual friction layers.

[0039] Both the positive and negative friction layer electrodes are made of metal thin films, specifically aluminum foil.

[0040] The above technical solution is only one feasible technical solution of the present invention. The scope of protection of the present invention is not limited thereto. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0041] Invention principle:

[0042] When the high-output triboelectric nanogenerator with dual friction layers is used, triboelectric charge is generated by the contact and friction between the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film.

[0043] Currently, methods to improve the output performance of triboelectric nanogenerators by reducing charge recombination mainly include: 1) establishing electron blocking layers or electron traps to limit charge drift between the triboelectric layer surface and the electrodes; 2) constructing charge transport layers or electron channels to transfer surface charge to the interior of the triboelectric layer; and 3) using external electric or magnetic fields to enhance the charge binding capacity of the triboelectric layer. However, electron blocking layers increase the thickness of the triboelectric layer, thereby reducing the output performance of the triboelectric nanogenerator. During the contact and separation process of the triboelectric layer, electron traps or charge transport layers may reduce the ability of the triboelectric layer to bind surface charge, leading to the formation of electron channels at the triboelectric layer interface. In addition, high doping concentrations of electron traps or channels can also cause short circuits between the triboelectric layer and the electrodes, resulting in a decrease in the output performance of the triboelectric nanogenerator.

[0044] Although a constant external magnetic field can drive charge movement to the triboelectric layer interface and generate a space charge region, it has no significant effect on suppressing charge recombination in non-ferromagnetic media. More importantly, previous studies have focused only on charge recombination in individual triboelectric layers, neglecting the synergistic effect between positive and negative triboelectric layers. Notably, electrons in ferromagnetic media are naturally spin-polarized at the Fermi level, implying the presence of numerous unpaired electrons on the ferromagnetic surface. According to the Zeeman interaction principle, a magnetic field can promote the transfer of unpaired electrons during the contact process between the two materials, further influencing the output performance of the triboelectric nanogenerator. Studies have shown that triboelectric nanogenerators generate alternating electromagnetic fields during contact and separation. Theoretically, introducing ferromagnetic media into triboelectric nanogenerators can improve electron transfer on the surface of the triboelectric layer and electron trapping within the layer, ultimately achieving high output performance.

[0045] The high-output triboelectric nanogenerator of the present invention, with its dual-friction-layer synergy, increases the surface charge density of the triboelectric nanogenerator by promoting charge transfer between the two friction layers when the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film come into contact. Furthermore, due to the spontaneous polarization of electrons in the ferromagnetic medium through exchange interactions, where electron spins are ordered, microscale magnetic domains can be formed. The electric field generated by the triboelectric nanogenerator drives holes or electrons on the surface of the friction layers to penetrate into the ordered magnetic domain region below the surface of the friction layers. Once the electron transfer in the external circuit of the triboelectric nanogenerator is complete, the electromagnetic field generated by the triboelectric nanogenerator dissipates. The magnetic domain region returns to a less ordered state. According to the laws of thermodynamics, the process from a disordered state to an ordered state is difficult to occur without external energy. Therefore, electrons or holes that have penetrated into the interior of the friction layers will be restricted from further drifting, thereby reducing charge recombination. On the other hand, the low conductivity of the friction layers also hinders the transfer of holes or electrons from the less ordered magnetic domain region to the surface of the friction layers.

[0046] In the preparation method of the present invention, if ferromagnetic nanoparticles are not used as fillers in the positive and negative friction layers, the suppression effect on charge recombination in the friction layer will be reduced, thus limiting the improvement of the output performance of the triboelectric nanogenerator. If the dual friction layers are not used to synergistically improve the output performance of the triboelectric nanogenerator, the role of ferromagnetic nanoparticles in the friction layer will be greatly reduced, limiting the further improvement of the output performance of the triboelectric nanogenerator.

[0047] If the process conditions are not within the range defined by this invention, the following adverse effects will occur:

[0048] 1) If the dissolution time of polyvinylidene fluoride and polyvinyl alcohol is too long or the dissolution temperature is too high, the solute in the solution will deteriorate, affecting the film quality of the composite film; if the dissolution time is too short or the dissolution temperature is too high, the solute will not dissolve completely, which will seriously affect the mechanical properties of the composite film.

[0049] 2) If the ultrasonic treatment and mechanical stirring time of the ferromagnetic nanoparticle / polyvinyl alcohol mixed solution and the ferromagnetic nanoparticle / polyvinylidene fluoride mixed solution is less than 1 hour, the ferromagnetic nanoparticles will agglomerate in the composite film, affecting the output performance of the triboelectric nanogenerator.

[0050] 3) If the voltage setting is too low or the jetting rate is too low during the electrospinning process, the syringe will leak liquid, which will seriously reduce the uniformity of the composite film surface. If the voltage setting is too high or the jetting rate is too high, the electrospinned fibers will be too fine and messy during the jetting process, which will also affect the output performance of the triboelectric nanogenerator.

[0051] The above invention has the following advantages or beneficial effects:

[0052] (1) The preparation method of the present invention is simple and low in cost. The composite film prepared by electrospinning has the characteristics of being lightweight and breathable, and can be applied to wearable devices.

[0053] (2) The present invention utilizes ferromagnetic nanoparticles to prepare composite films, which on the one hand effectively inhibits the recombination of charges in the friction layer and charges on the electrode, and on the other hand promotes the transfer of surface charges between the two friction layers, thereby increasing the surface charge density of the triboelectric nanogenerator.

[0054] (3) This invention utilizes the synergistic effect of the double friction layer to improve the output performance of the triboelectric nanogenerator, achieving 14.2 W / m. 2 Its ultra-high power density, 240V open-circuit voltage, and 46mA / m 2 Its short-circuit current density can be used to drive small electronic devices and wearable devices, showing promising application prospects. Attached Figure Description

[0055] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings. The drawings are not drawn to scale; their focus is on illustrating the gist of the invention.

[0056] Figure 1 This is a schematic diagram of the triboelectric nanogenerator with synergistic effect of two friction layers according to the present invention.

[0057] Figure 2X-ray diffraction patterns of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film prepared in Example 1.

[0058] Figure 3 The hysteresis loop diagrams are of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film prepared in Example 1.

[0059] Figure 4 The open-circuit voltage diagram of the triboelectric nanogenerator with synergistic effect of the two friction layers prepared in Example 1 is shown.

[0060] Figure 5 The short-circuit current diagram is shown for the triboelectric nanogenerator with synergistic effect of the two friction layers prepared in Example 1.

[0061] Figure 6 The open-circuit voltage diagram of the triboelectric nanogenerator with synergistic effect of the two friction layers prepared in Example 2;

[0062] Figure 7 The short-circuit current diagram of the triboelectric nanogenerator with synergistic effect of the double friction layers prepared in Example 2 is shown.

[0063] Figure 8 The open-circuit voltage diagram of the triboelectric nanogenerator with synergistic effect of the two friction layers prepared in Example 3;

[0064] Figure 9 The short-circuit current diagram is shown for the triboelectric nanogenerator with synergistic effect of the double friction layers prepared in Example 3.

[0065] Figure 10 The graph shows a comparison of the open-circuit voltage, short-circuit current density, and transferred charge of the triboelectric nanogenerators with synergistic effect of double triboelectric layers prepared in Examples 1 to 3 and the triboelectric nanogenerators of the control group.

[0066] Figure 11 This is a comparison chart of the charge recombination rates of the triboelectric nanogenerators with synergistic effects of double friction layers prepared in Examples 1 to 3 and the triboelectric nanogenerators in the control group.

[0067] Figure 12 The graph shows a comparison of the instantaneous power density of the triboelectric nanogenerators with synergistic effects of the double friction layers prepared in Examples 1 to 3 and the triboelectric nanogenerators in the control group.

[0068] Figure 13 The open-circuit voltage diagram of the triboelectric nanogenerator with synergistic effect of the two friction layers prepared in Example 4;

[0069] Figure 14 The short-circuit current diagram of the triboelectric nanogenerator with synergistic effect of the double friction layers prepared in Example 4 is shown.

[0070] Among them, 1-positive friction layer electrode; 2-ferromagnetic nanoparticle / polyvinyl alcohol composite film; 3-ferromagnetic nanoparticles; 4-ferromagnetic nanoparticle / polyvinylidene fluoride composite film; 5-negative friction layer electrode; 6-external circuit. Detailed Implementation

[0071] The structure of the present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0072] In the following examples, the polyvinyl alcohol particles used were Aladdin polyvinyl alcohol 1788 with a degree of alcoholysis of 87.0-89.0% (mol / mol), the polyvinylidene fluoride was produced by Aladdin (Mw=534000), the DMF was from Shanghai Taikang, the acetone was from Guangzhou Chemical Reagent, the ferromagnetic nanoparticles in Examples 1-3 were ChengYue nickel powder nanoparticles (diameter 200-300nm), and the ferromagnetic nanoparticles in Example 4 were ChengYue iron oxide nanoparticles (diameter 200-300nm).

[0073] Example 1

[0074] A method for preparing a high-output triboelectric nanogenerator with dual friction layers includes the following steps:

[0075] S1: Weigh 10g of deionized water and 0.87g of polyvinyl alcohol granules into a reagent bottle, heat and stir with a magnetic stirrer to dissolve, heating temperature 80℃, heating time 3h to obtain polyvinyl alcohol solution, weigh 0.0178g of ferromagnetic nanoparticles and add them to the polyvinyl alcohol solution, sonicate and mechanically stir for 2h to obtain ferromagnetic nanoparticle / polyvinyl alcohol suspension with a mass fraction of 2wt%;

[0076] S2: Weigh 6g DMF, 4g acetone and 2.2g polyvinylidene fluoride particles, and dissolve them by heating with a magnetic stirrer at 90℃ for 0.5h to obtain a polyvinylidene fluoride solution. Weigh 0.0449g ferromagnetic nanoparticles and add them to the polyvinylidene fluoride solution. Sonicate and mechanically stir for 2h to obtain a ferromagnetic nanoparticle / polyvinylidene fluoride suspension with a ferromagnetic nanoparticle mass fraction of 2wt%.

[0077] S3: Using a syringe, draw 10 mL of ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension respectively. The low voltage of the electrospinning equipment is set to -3 kV, the high voltage is set to 8 kV, and the injection rate of the syringe is 1 mm·min. -1After collecting for 8 hours on a drum collector, two ferromagnetic nanoparticle / polyvinyl alcohol composite films with a mass fraction of 2wt% and ferromagnetic nanoparticle / polyvinylidene fluoride composite films with a mass fraction of 2wt% were obtained.

[0078] S4: Cut 2cm×2cm ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Attach a positive tribological electrode (aluminum foil) to one side of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and a negative tribological electrode (aluminum foil) to the ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Connect the positive and negative tribological electrodes with lead wires to an external circuit as signal output terminals. Position the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film opposite each other to obtain a high-output triboelectric nanogenerator with dual tribological layers.

[0079] High-output triboelectric nanogenerator with dual friction layers such as Figure 1 As shown, it includes a ferromagnetic nanoparticle / polyvinyl alcohol composite film 2, a positive friction layer electrode 1, a ferromagnetic nanoparticle / polyvinylidene fluoride composite film 4, a negative friction layer electrode 5, and an external circuit 6.

[0080] Both the ferromagnetic nanoparticle / polyvinyl alcohol composite film 2 and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film 4 contain ferromagnetic nanoparticles 3.

[0081] Ferromagnetic nanoparticle / polyvinyl alcohol composite film 2 is attached to positive friction layer electrode 1, and ferromagnetic nanoparticle / polyvinylidene fluoride composite film 4 is attached to negative friction layer electrode 5. Positive friction layer electrode 1 and negative friction layer electrode 5 are connected through external circuit 6 and ferromagnetic nanoparticle / polyvinyl alcohol composite film 2 and ferromagnetic nanoparticle / polyvinylidene fluoride composite film 4 are arranged opposite to each other.

[0082] The X-ray diffraction patterns of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film prepared in this embodiment are as follows: Figure 2 As shown, the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film have three broad peaks at 44.5°, 51.9° and 76.3°, which correspond to (111), (200) and (220) of nickel nanoparticles, respectively, indicating that nickel nanoparticles were successfully doped into the composite film.

[0083] The hysteresis loop diagrams of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film prepared in this embodiment are as follows: Figure 3 As shown, the composite film exhibits certain ferromagnetic properties.

[0084] The voltage and current density of the high-output triboelectric nanogenerator with dual-friction layer synergy prepared in this embodiment are as follows: Figure 4 and Figure 5 As shown, from Figure 4 and 5 As can be seen from the data, the high-output triboelectric nanogenerator with dual friction layers prepared in this embodiment has an output voltage of 116V and a current density of 15.75mA / m. 2 .

[0085] Example 2

[0086] A method for preparing a high-output triboelectric nanogenerator with dual friction layers includes the following steps:

[0087] S1: Weigh 10g of deionized water and 0.87g of polyvinyl alcohol granules into a reagent bottle, heat and stir with a magnetic stirrer to dissolve, heating temperature 80℃, heating time 3h to obtain polyvinyl alcohol solution, weigh 0.097g of ferromagnetic nanoparticles and add them to the polyvinyl alcohol solution, sonicate and mechanically stir for 2h to obtain a ferromagnetic nanoparticle / polyvinyl alcohol suspension with a ferromagnetic nanoparticle mass fraction of 10wt%.

[0088] S2: Weigh 6g DMF, 4g acetone and 2.2g polyvinylidene fluoride particles, and dissolve them by heating with a magnetic stirrer at 80℃ for 1h to obtain a polyvinylidene fluoride solution. Weigh 0.14g ferromagnetic nanoparticles and add them to the polyvinylidene fluoride solution. Sonicate and mechanically stir for 2h to obtain a ferromagnetic nanoparticle / polyvinylidene fluoride suspension with a ferromagnetic nanoparticle mass fraction of 6wt%.

[0089] S3: Using a syringe, 10 mL of ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension were drawn respectively. The low voltage of the electrospinning equipment was set to -3 kV and the high voltage was set to 8 kV. The injection rate of the syringe was 1 mm min-1. The suspension was collected on a roller collector for 9 h to obtain ferromagnetic nanoparticle / polyvinyl alcohol composite film with a ferromagnetic nanoparticle mass fraction of 10 wt% and ferromagnetic nanoparticle / polyvinylidene fluoride composite film with a ferromagnetic nanoparticle mass fraction of 6 wt%.

[0090] S4: Cut 2cm×2cm ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Attach a positive tribological electrode to one side of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and a negative tribological electrode to the ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Connect the positive and negative tribological electrodes with lead wires to an external circuit as signal output terminals. Position the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film opposite each other to obtain a high-output triboelectric nanogenerator with dual tribological layers.

[0091] The voltage and current density of the high-output triboelectric nanogenerator with dual-friction layer synergy prepared in this embodiment are as follows: Figure 6 and Figure 7 As shown, from Figure 6 and 7 As can be seen from the data, the high-output triboelectric nanogenerator with dual-friction layer synergy prepared in this embodiment has an output voltage of 240V and a current density of 40mA / m. 2 .

[0092] Example 3

[0093] A method for preparing a high-output triboelectric nanogenerator with dual friction layers includes the following steps:

[0094] S1: Weigh 10g of deionized water and 0.87g of polyvinyl alcohol granules into a reagent bottle, heat and stir with a magnetic stirrer to dissolve, heating temperature 90℃, heating time 2.5h to obtain polyvinyl alcohol solution, weigh 0.142g of ferromagnetic nanoparticles and add them to the polyvinyl alcohol solution, sonicate and mechanically stir for 2h to obtain a ferromagnetic nanoparticle / polyvinyl alcohol suspension with a ferromagnetic nanoparticle mass fraction of 14wt%;

[0095] S2: Weigh 6g DMF, 4g acetone and 2.2g polyvinylidene fluoride particles, and dissolve them by heating with a magnetic stirrer at 80℃ for 1h to obtain a polyvinylidene fluoride solution. Weigh 0.244g ferromagnetic nanoparticles and add them to the polyvinylidene fluoride solution. Sonicate and mechanically stir for 2h to obtain a ferromagnetic nanoparticle / polyvinylidene fluoride suspension with a ferromagnetic nanoparticle mass fraction of 10wt%.

[0096] S3: Using a syringe, 10 mL of ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension were drawn respectively. The low voltage of the electrospinning equipment was set to -3 kV and the high voltage was set to 8 kV. The injection rate of the syringe was 1 mm min-1. The suspension was collected on a roller collector for 9 h to obtain ferromagnetic nanoparticle / polyvinyl alcohol composite film with a ferromagnetic nanoparticle mass fraction of 14 wt% and ferromagnetic nanoparticle / polyvinylidene fluoride composite film with a ferromagnetic nanoparticle mass fraction of 10 wt%.

[0097] S4: Cut 2cm×2cm ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Attach a positive tribological electrode to one side of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and a negative tribological electrode to the ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Connect the leads from the positive and negative tribological electrodes to an external circuit as signal output terminals. Position the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film opposite each other to obtain a high-output triboelectric nanogenerator with dual tribological layers.

[0098] The voltage and current density of the high-output triboelectric nanogenerator with dual-friction layer synergy prepared in this embodiment are as follows: Figure 8 and Figure 9 As shown, from Figure 8 and 9 As can be seen from the data, the high-output triboelectric nanogenerator with dual-friction layer synergy prepared in this embodiment has an output voltage of 137V and a current density of 19.75mA / m. 2 .

[0099] The comparison of current density, charge density, and instantaneous power density of the high-output triboelectric nanogenerators with dual-friction layer synergy prepared in Examples 1, 2, and 3 with the control group is shown in the figure below. Figure 10 As shown, the control group consisted of triboelectric nanogenerators based on pure polyvinyl alcohol film (without the addition of ferromagnetic nanoparticles to the suspension, unlike the examples) and polyvinylidene fluoride film (without the addition of ferromagnetic nanoparticles to the suspension, unlike the examples). A statistical comparison of the charge recombination rates of the high-output triboelectric nanogenerators with dual-friction layer synergy prepared in Examples 1, 2, and 3 with the control group is shown below. Figure 11 As shown, ferromagnetic nanoparticles significantly reduce the charge recombination rate, and the synergistic effect of the dual friction layers greatly improves the output performance of the triboelectric nanogenerator. A comparison of the instantaneous output power of the high-output triboelectric nanogenerators with dual friction layer synergy prepared in Examples 1, 2, and 3 with the control group is shown below. Figure 12 As shown, the maximum power density is 14.2 W / m². 2 It was 36.4 times higher than the control group.

[0100] Example 4

[0101] A method for preparing a high-output triboelectric nanogenerator with dual friction layers includes the following steps:

[0102] S1: Weigh 10g of deionized water and 0.87g of polyvinyl alcohol granules into a reagent bottle, heat and stir with a magnetic stirrer to dissolve, heating temperature 80℃, heating time 3h to obtain polyvinyl alcohol solution, weigh 0.0362g of ferromagnetic nanoparticles and add them to the polyvinyl alcohol solution, sonicate and mechanically stir for 1.5h to obtain a ferromagnetic nanoparticle / polyvinyl alcohol suspension with a ferromagnetic nanoparticle mass fraction of 4wt%;

[0103] S2: Weigh 6g DMF, 4g acetone and 2.2g polyvinylidene fluoride particles, and dissolve them by heating with a magnetic stirrer at 90℃ for 0.5h to obtain a polyvinylidene fluoride solution. Weigh 0.0917g ferromagnetic nanoparticles and add them to the polyvinylidene fluoride solution. Sonicate and mechanically stir for 1.5h to obtain a ferromagnetic nanoparticle / polyvinylidene fluoride suspension with a ferromagnetic nanoparticle mass fraction of 4wt%.

[0104] S3: Using a syringe, draw 10 mL of ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension respectively. The low voltage of the electrospinning equipment is set to -3 kV, the high voltage is set to 8 kV, and the injection rate of the syringe is 1 mm·min. -1 After collecting for 8 hours on a drum collector, two ferromagnetic nanoparticle / polyvinyl alcohol composite films with a mass fraction of 4 wt% and ferromagnetic nanoparticle / polyvinylidene fluoride composite films with a mass fraction of 4 wt% were obtained.

[0105] S4: Cut 2cm×2cm ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Attach a positive tribological electrode (aluminum foil) to one side of the ferromagnetic nanoparticle / polyvinyl alcohol composite film and a negative tribological electrode (aluminum foil) to the ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Connect the positive and negative tribological electrodes with lead wires to an external circuit as signal output terminals. Position the ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film opposite each other to obtain a high-output triboelectric nanogenerator with dual tribological layers.

[0106] The voltage and current density of the high-output triboelectric nanogenerator with dual-friction layer synergy prepared in this embodiment are as follows: Figure 13 and Figure 14 As shown, from Figure 13 and 14As can be seen from the data, the high-output triboelectric nanogenerator with dual-friction layer synergy prepared in this embodiment has an output voltage of 150V and a current density of 21mA / m. 2 .

[0107] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments, which will not be elaborated here. Such variations do not affect the essence of the present invention, and will not be elaborated here either.

[0108] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A method for preparing a high-output triboelectric nanogenerator with dual friction layers, characterized in that: Includes the following steps: (1) Prepare ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension; the preparation method of the ferromagnetic nanoparticle / polyvinyl alcohol suspension is as follows: Polyvinyl alcohol and water are mixed, heated and stirred to dissolve to obtain a polyvinyl alcohol aqueous solution. Ferromagnetic nanoparticles are then added to the polyvinyl alcohol aqueous solution and subjected to ultrasonic treatment and mechanical stirring for 1-2 hours to obtain a ferromagnetic nanoparticle / polyvinyl alcohol suspension. The preparation method of the ferromagnetic nanoparticle / polyvinylidene fluoride suspension is as follows: An N,N-dimethylformamide / acetone solution was prepared by mixing N,N-dimethylformamide solution and acetone solution. Polyvinylidene fluoride was added to the N,N-dimethylformamide / acetone solution and heated and stirred to dissolve, thus obtaining a polyvinylidene fluoride solution. Ferromagnetic nanoparticles were added to the polyvinylidene fluoride solution, ultrasonicated, and mechanically stirred for 1-2 hours to obtain a ferromagnetic nanoparticle / polyvinylidene fluoride suspension. (2) Ferromagnetic nanoparticle / polyvinyl alcohol suspension and ferromagnetic nanoparticle / polyvinylidene fluoride suspension were respectively made into ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film. (3) After combining the ferromagnetic nanoparticle / polyvinyl alcohol composite film with the positive friction layer electrode and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film with the negative friction layer electrode, the positive friction layer electrode and the negative friction layer electrode are connected by an external circuit to obtain a high-output triboelectric nanogenerator with dual friction layers.

2. The method for preparing a high-output triboelectric nanogenerator with dual friction layers according to claim 1, characterized in that, The polyvinyl alcohol aqueous solution contains 5-10 wt% polyvinyl alcohol, is heated at 70-100°C, and has a dissolution time of 1-3 hours. The ferromagnetic nanoparticles have a particle size of 200~300nm; The mass fraction of the ferromagnetic nanoparticles in the ferromagnetic nanoparticle / polyvinyl alcohol suspension is 0.01~14wt%.

3. The method for preparing a high-output triboelectric nanogenerator with dual friction layers according to claim 1, characterized in that, The mass ratio of N,N-dimethylformamide to acetone in the N,N-dimethylformamide / acetone solution is 4:3 to 2:

1. The mass fraction of the polyvinylidene fluoride in the polyvinylidene fluoride solution is 10~20wt%; The heating temperature is 70~100℃, and the heating and stirring time is 0.5~1h; The ferromagnetic nanoparticles have a particle size of 200-300 nm; the mass fraction of the ferromagnetic nanoparticles in the ferromagnetic nanoparticle / polyvinylidene fluoride suspension is 0.01-10 wt%.

4. The method for preparing a high-output triboelectric nanogenerator with dual friction layers according to claim 1, characterized in that, The ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film were prepared using electrospinning technology.

5. The method for preparing a high-output triboelectric nanogenerator with dual friction layers according to claim 1, characterized in that, Step (3) is as follows: A certain area of ​​ferromagnetic nanoparticle / polyvinyl alcohol composite film and ferromagnetic nanoparticle / polyvinylidene fluoride composite film are cut. A positive friction layer electrode is attached to one side of the ferromagnetic nanoparticle / polyvinyl alcohol composite film, and a negative friction layer electrode is attached to the ferromagnetic nanoparticle / polyvinylidene fluoride composite film. Wires are led out from the positive and negative friction layer electrodes and connected to an external circuit as signal output terminals. The ferromagnetic nanoparticle / polyvinyl alcohol composite film and the ferromagnetic nanoparticle / polyvinylidene fluoride composite film are arranged opposite to each other to obtain a high-output triboelectric nanogenerator with dual friction layers. Both the positive and negative friction layer electrodes are made of metal thin films.

6. A high-output triboelectric nanogenerator with dual-friction layer synergy, prepared by the method according to any one of claims 1 to 5, characterized in that: It includes a positive friction layer containing ferromagnetic nanoparticles, a negative friction layer containing ferromagnetic nanoparticles, a positive friction layer electrode, a negative friction layer electrode, and an external circuit. The positive friction layer is attached to the positive friction layer electrode, and the negative friction layer is attached to the negative friction layer electrode. The positive friction layer electrode and the negative friction layer electrode are connected through an external circuit and are arranged opposite to each other.

7. A high-output triboelectric nanogenerator with dual friction layers according to claim 6, characterized in that, Both the positive and negative friction layers are loaded with ferromagnetic nanoparticles.

8. A high-output triboelectric nanogenerator with dual friction layers according to claim 6, characterized in that, The positive friction layer containing ferromagnetic nanoparticles is a ferromagnetic nanoparticle / polyvinyl alcohol composite film, and the negative friction layer containing ferromagnetic nanoparticles is a ferromagnetic nanoparticle / polyvinylidene fluoride composite film.

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