Foam copper skeleton-based heterostructure material for friction nanogenerator and preparation method and application thereof

Abstract

This invention discloses a copper foam framework-based heterogeneous material for triboelectric nanogenerators, its preparation method, and its application. The copper foam framework-based heterogeneous material uses copper foam as the framework and platinum-catalyzed silicone rubber as the filler, forming a three-dimensional interpenetrating structure. The preparation method is as follows: Step (1) The copper foam is first ultrasonically cleaned in anhydrous ethanol, then ultrasonically cleaned in dilute hydrochloric acid; Step (2) A platinum-catalyzed silicone rubber solution is prepared; Step (3) The platinum-catalyzed silicone rubber solution is poured into the copper foam until the pores are completely filled; Step (4) After pouring, the mold is transferred to an ultrasonic venting treatment; Step (5) The mold is placed in a drying oven for curing. The copper foam framework-based heterogeneous material for triboelectric nanogenerators prepared by this invention can be used as a three-dimensional electrode in triboelectric nanogenerators, effectively improving the electrical output performance of the triboelectric nanogenerator.

Description

Technical Field

[0001] This invention relates to the field of triboelectric nanogenerator technology. Specifically, it relates to foamed copper framework-based heterogeneous materials for triboelectric nanogenerators, their preparation methods, and applications. Background Technology

[0002] With the rapid development of the Internet of Things and distributed sensor networks globally, and the progress of human society, the demand for sustainable, distributed micro-energy is becoming increasingly urgent due to the deployment of a large number of micro-devices. Since Academician Wang Zhonglin's team first discovered the contact electrification effect in piezoelectric materials and invented the triboelectric nanogenerator (TENG) in 2012, TENG has attracted the attention of many research teams around the world due to its high sensitivity, high mechanical energy conversion efficiency, and especially its excellent capture ability and high energy conversion efficiency for low-frequency mechanical energy (<50Hz). Vast amounts of low-frequency energy are widely distributed in nature, such as wind energy, vibration energy, low-frequency ocean current energy, and biological motion. Compared with the characteristics of traditional fossil energy—high energy reserves, concentrated distribution, and easy access—this type of energy is fragmented, widely distributed, non-directional, and low-density, and is called "high-entropy energy." Traditional electromagnetic generators (EMGs) are difficult to capture and utilize.

[0003] TENG directly converts mechanical energy into electrical energy based on the coupling principle of contact electrification and electrostatic induction. Its core working mechanism involves periodically contacting and separating two materials with different electron affinities, thereby driving the directional flow of free electrons in an external load to generate current.

[0004] Triboelectric generators (TENGs) exhibit extremely high sensitivity to low-frequency conditions, maintaining stable electrical signal output even at operating frequencies of 0.1–3 Hz. Their force resolution can reach as low as 5 N, perfectly matching the low-frequency characteristics of high-entropy energy sources. Furthermore, a wide range of triboelectric materials can be selected, including polymers, metals, and biomaterials, which are readily available, low-cost, and easy to process. TENGs also offer flexible structures, allowing for designs such as vertical contact separation, horizontal sliding, single-electrode, and independent layer configurations.

[0005] The selection, combination, and adaptability of different friction materials and operating modes directly affect the electrical output performance, operational stability, and corrosion resistance of the device. Diverse combination schemes offer a wealth of possibilities for designing TENG devices and self-powered monitoring sensors that combine environmental adaptability with excellent electrical output performance, enabling them to specifically capture high-entropy energy in specific environments and achieve accurate sensing of changes in the external environment. However, traditional TENG friction layers struggle to maintain a balance between wear resistance and high electrical output performance.

[0006] Currently, most triboelectric nanogenerators (TENGs) employ planar electrodes. To improve their electrical output performance, existing research largely focuses on modifying and optimizing dielectric materials, while research and design of the conductive electrodes themselves are relatively scarce. Therefore, this invention innovatively proposes a three-dimensional electrode strategy to effectively enhance the electrical output performance of TENGs. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is to provide a foamed copper framework-based heterogeneous material for triboelectric nanogenerators, its preparation method and application, so as to solve the problem that traditional TENG triboelectric layers are difficult to maintain a balance between mechanical stability and high electrical output performance.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] The foamed copper framework-based heterogeneous material for triboelectric nanogenerators uses foamed copper with a pore density of 20-80 PPI as the framework and platinum-catalyzed silicone rubber liquid obtained by mixing platinum-catalyzed silicone rubber matrix and platinum-catalyzed silicone rubber curing agent at a mass ratio of 1:1 as the filler. The foamed copper and platinum-catalyzed silicone rubber liquid are cured to form a three-dimensional interpenetrating structure, that is, platinum-catalyzed silicone rubber fills the pores of foamed copper and coats the surface of foamed copper. Because the platinum-catalyzed silicone rubber liquid formed by mixing the platinum-catalyzed silicone rubber matrix and the platinum-catalyzed silicone rubber curing agent has poor wettability with copper, and because the platinum-catalyzed silicone rubber liquid needs to fill the pores of the foamed copper before curing, selecting foamed copper with a pore density of 20-80 PPI as the skeleton can well match the platinum-catalyzed silicone rubber liquid formed by mixing the platinum-catalyzed silicone rubber matrix and the platinum-catalyzed silicone rubber curing agent at a mass ratio of 1:1. This avoids the problem of the pore density being too small, which would affect the fluidity of the platinum-catalyzed silicone rubber liquid and prevent it from filling the pores before curing, while ensuring the wettability between the platinum-catalyzed silicone rubber liquid and the pores, allowing all the gas in the pores to be squeezed out through the natural flow of the platinum-catalyzed silicone rubber liquid. When the foamed copper skeleton-based heterogeneous material formed by the two is used as the three-dimensional electrode of the triboelectric nanogenerator, the triboelectric effect of the platinum-catalyzed silicone rubber and the charge generated by the electrostatic induction of the foamed copper can be conducted by the foamed copper in a timely manner, thereby significantly improving its electrical output performance.

[0010] Platinum-catalyzed silicone rubber (PCBR) is a type of organosilicon material that uses platinum compounds as catalysts to achieve cross-linking and curing through hydrosilylation. It boasts advantages such as high curing efficiency and strong performance controllability, and is widely used in high-end manufacturing, electronics, medical, and new energy fields. The PCBR used in this invention can utilize the Ecoflex series of platinum-catalyzed silicone rubber manufactured by Smooth-On. Copper foam possesses certain strength and good electrical conductivity; the copper foam framework-based heterogeneous material formed by its combination with PCBR has a wider range of applications and stronger impact resistance.

[0011] The preparation method of foamed copper framework-based heterogeneous materials for triboelectric nanogenerators includes the following steps:

[0012] Step (1): Cut the copper foam with a pore density of 20-80 PPI into the preset size, place it in anhydrous ethanol for a first ultrasonic cleaning, blow it dry, and then place it in dilute hydrochloric acid for a second ultrasonic cleaning. After the second ultrasonic cleaning, let it air dry for later use.

[0013] Step (2): Prepare the platinum catalytic silicone rubber liquid and perform the first degassing treatment under ultrasonic conditions. Performing the first degassing treatment on the platinum catalytic silicone rubber liquid before casting can avoid the introduction of air bubbles. Once air bubbles are introduced, especially at the interface between the copper foam and the platinum catalytic silicone rubber, even if a longer ultrasonic degassing treatment is performed after casting, it may lead to a decrease in the bonding strength between the copper foam and the platinum catalytic silicone rubber interface, which weakens the mechanical interlocking effect and thus leads to a decrease in the mechanical stability and electrical output performance of the final copper foam skeleton-based heterogeneous material. The present invention performs degassing treatment on the platinum catalytic silicone rubber liquid before casting, which can effectively avoid the problem of decreased mechanical stability and electrical output performance of the copper foam skeleton-based heterogeneous material caused by the introduction of air bubbles.

[0014] Step (3): At room temperature, place the foamed copper at the bottom of the mold, and pour the platinum catalytic silicone rubber liquid obtained by mixing the platinum catalytic silicone rubber matrix and the platinum catalytic silicone rubber curing agent in a mass ratio of 1:1 into the foamed copper along the corner of the mold. The natural flow of the platinum catalytic silicone rubber liquid completely fills the pores of the foamed copper. During the time gap before curing, pour the liquid platinum catalytic silicone rubber liquid into the pores of the foamed copper. The pore density of the foamed copper and the fluidity of the prepared platinum catalytic silicone rubber liquid can be matched with each other. The natural flow of the platinum catalytic silicone rubber liquid squeezes out all the gas in the pores, ensuring complete filling. The two are tightly bonded and without defects.

[0015] Step (4): After casting is completed, the mold is transferred to ultrasonic conditions for a second venting process.

[0016] Step (5): After the second exhaust treatment is completed, the mold is placed in a drying oven for curing. After the curing treatment is completed, the foam copper skeleton-based heterogeneous material for triboelectric nanogenerator is obtained.

[0017] Considering the poor wettability between platinum-catalyzed silicone rubber liquid and copper, and the requirement that the platinum-catalyzed silicone rubber liquid fill the pores of the copper foam before curing, copper foam with a pore density of 20-80 PPI was selected as the skeleton to ensure the successful preparation of the copper foam skeleton-based heterogeneous material. It can be well matched with the platinum-catalyzed silicone rubber liquid formed by mixing the platinum-catalyzed silicone rubber matrix and the platinum-catalyzed silicone rubber curing agent at a mass ratio of 1:1. This avoids the problem of the pore density being too small, which would affect the fluidity of the platinum-catalyzed silicone rubber liquid and prevent it from filling the pores before curing. At the same time, it ensures the wettability between the platinum-catalyzed silicone rubber liquid and the pores, allowing all the gas in the pores to be squeezed out through the natural flow of the platinum-catalyzed silicone rubber liquid.

[0018] In the preparation method of the above-mentioned copper foam framework-based heterogeneous material for triboelectric nanogenerator, in step (1), the mass fraction of copper in the copper foam is greater than or equal to 99.90 wt%; the time for the first ultrasonic cleaning is 3-8 min; the molar concentration of dilute hydrochloric acid is 0.3-0.7 mol / L; the time for the second ultrasonic cleaning is 3-8 min; the ultrasonic conditions for the first and second ultrasonic cleaning are the same: ultrasonic power 100-150 W, ultrasonic frequency 35-45 KHz, and ultrasonic temperature 30-40 ℃.

[0019] In the preparation method of the foamed copper framework-based heterogeneous material for the above-mentioned triboelectric nanogenerator, in step (2), the platinum catalytic silicone rubber liquid is prepared according to the instructions for use of Ecoflex 00-50 platinum catalytic silicone rubber produced by Smooth-On; the first exhaust treatment time is 3-7 min; during the first exhaust treatment: ultrasonic power 100-150W, ultrasonic frequency 35-45KHz, ultrasonic temperature 30-40℃. Ecoflex 00-50, as a flexible polymer material, has both flexibility and wear resistance, and has a relatively high dielectric constant. In the three-dimensional interpenetrating structure formed by it and foamed copper, the interface bonding strength between silicone rubber and foamed copper is high, which is more conducive to charge transport.

[0020] In the above-mentioned method for preparing copper foam skeleton-based heterogeneous materials for triboelectric nanogenerators, in step (3), the mass ratio of copper foam to platinum catalytic silicone rubber liquid is 1:2-3. Under this ratio, when the copper foam skeleton-based heterogeneous material formed by the two is used as a three-dimensional electrode of the triboelectric nanogenerator, the friction effect of platinum catalytic silicone rubber and the charge generated by electrostatic induction of copper foam can be conducted by copper foam in a timely manner, thereby significantly improving its electrical output performance. In addition, within this ratio range, copper foam, as a structural skeleton, can uniformly disperse the external force acting inside the material, further improving the electrical output performance and mechanical stability of the copper foam skeleton-based heterogeneous material. The pouring rate of platinum catalytic silicone rubber liquid is 40-80 mL / min, which can effectively reduce the influence of bubble introduction on the comprehensive performance of composite materials.

[0021] The above-mentioned method for preparing foamed copper skeleton-based heterogeneous materials for triboelectric nanogenerators includes step (4), the second exhaust treatment time is 1-2 min; during the second exhaust treatment: ultrasonic power 100-150W, ultrasonic frequency 35-45KHz, ultrasonic temperature 30-40℃.

[0022] In the above-mentioned method for preparing copper foam skeleton-based heterogeneous materials for triboelectric nanogenerators, the curing conditions in step (5) are: curing temperature 50-70℃, curing time 1-3h, or curing at room temperature for 24h. If the curing time is too short, the platinum catalytic silicone rubber will be difficult to cure completely, and the sticky surface of the copper foam skeleton-based heterogeneous material will result in poor mechanical stability. If the curing time is too long, the prepared copper foam skeleton-based heterogeneous material will become hard and brittle, easily cracked, and its flexibility will decrease or even be lost, making demolding difficult. Under the curing conditions of the present invention, the platinum catalytic silicone rubber can be completely cured and maintain its unique flexibility. At the same time, the interface bonding between the platinum catalytic silicone rubber and the copper foam is also good, so that the copper foam skeleton-based heterogeneous material has good mechanical stability and electrical output performance.

[0023] The above-mentioned method for preparing copper foam framework-based heterogeneous materials for triboelectric nanogenerators includes the following steps: In step (1), the copper foam is made of T2 copper (copper foam made of T2 copper has excellent conductivity, ductility and mechanical properties, and can provide the required conductive path and structural support for the three-dimensional framework), the pore density of the copper foam is 80 PPI; the time for the first ultrasonic cleaning is 5 min; the molar concentration of dilute hydrochloric acid is 0.5 mol / L; the time for the second ultrasonic cleaning is 5 min; the ultrasonic conditions for the first and second ultrasonic cleanings are the same: ultrasonic power 120 W, ultrasonic frequency 40 kHz, ultrasonic temperature 35 °C; In step (2), the platinum catalytic silicone rubber liquid is the platinum catalytic silicone rubber Ecoflex produced by Smooth-On. Prepare according to the instructions for use of 00-50; the first exhaust treatment time is 4min, ultrasonic power is 120W, ultrasonic frequency is 40KHz, and temperature is 35℃; in step (3), the mass ratio of foamed copper to platinum catalytic silicone rubber liquid is 1:2; the pouring rate of platinum catalytic silicone rubber liquid is 60mL / min; in step (4), the second exhaust treatment time is 2min, ultrasonic power is 120W, ultrasonic frequency is 40KHz, and temperature is 35℃; in step (5), the curing conditions are: curing temperature 60℃ and curing time 24h.

[0024] The application of copper foam framework-based heterogeneous materials for triboelectric nanogenerators involves using the copper foam framework-based heterogeneous materials for triboelectric nanogenerators prepared by the above-mentioned preparation method as 3D electrodes for triboelectric nanogenerators.

[0025] The technical solution of the present invention achieves the following beneficial technical effects:

[0026] 1. This invention relates to a method for preparing a copper foam skeleton-based heterogeneous material for triboelectric nanogenerators (TENGs). The method uses copper foam with a porosity of 20-80 PPI as a three-dimensional electrode, and platinum-catalyzed silicone rubber Ecoflex 00-50 (obtained by mixing a platinum-catalyzed silicone rubber matrix and a platinum-catalyzed silicone rubber curing agent at a mass ratio of 1:1) as the filler material for the copper foam skeleton and the friction layer material for the TENG. This successfully prepares a composite material that organically combines the TENG electrode layer and the friction layer, breaking through the previous size limitations of the friction layer film thickness and improving the design flexibility of macroscopic TENG devices. When the copper foam skeleton-based heterogeneous material prepared using this method is combined with polyoxymethylene (POM) microspheres with strong electron-donating capabilities to form a TENG testing device, the output is stable under experimental conditions of a 30 mm movement amplitude and a 5 Hz movement frequency, generating a maximum transferred charge of 9.60 nC, a maximum short-circuit current of 165.38 nA, and a maximum open-circuit voltage of 29.44 V. Compared with copper foil as the electrode material, the transferred charge of the copper foam skeleton-based heterogeneous material is increased by 242%.

[0027] 2. The present invention relates to a method for preparing a copper foam framework-based heterogeneous material for triboelectric nanogenerators. This method selects copper foam with a specific pore density and a specific type of platinum-catalyzed silicone rubber liquid (Ecoflex 00-50) as raw materials. Before casting, the Ecoflex 00-50 liquid is degassed. During casting, the casting rate of the Ecoflex 00-50 liquid and its mass ratio to the copper foam with the specific pore density are controlled. A second degaussing process is performed after casting. By selecting appropriate curing temperatures and times, the prepared copper foam framework-based heterogeneous material can maintain good flexibility while exhibiting a tighter interfacial bond with the copper foam, thereby significantly improving the mechanical stability and electrical output performance of the copper foam framework-based heterogeneous material.

[0028] 3. This invention relates to a copper foam framework-based heterogeneous material for triboelectric nanogenerators (TENGs). Utilizing the three-dimensional structure of copper foam and the plasticity of platinum-catalyzed silicone rubber (Ecoflex), a three-dimensional interpenetrating heterogeneous material is ingeniously constructed. Traditional TENG friction components employ a layered structure, fabricating various friction layer films on copper foil electrodes. However, the copper foam framework-based heterogeneous material prepared in this invention features a unique three-dimensional interpenetrating structure that creates a three-dimensional interlock between copper foam and Ecoflex in spatial orientation, significantly improving mechanical properties and operational stability. Furthermore, TENG operation is based on the coupling principle of contact electrification and electrostatic induction, both of which constrain the dimensional design of traditional TENG friction layer film stacks, making it difficult to maintain a balance between mechanical stability and high electrical output performance. Compared with copper foil of the same area, the foamed copper skeleton-based heterogeneous material prepared by this invention has a significantly increased surface area. Its three-dimensional interpenetrating structure effectively increases the electrostatic induction contact area between copper and Ecoflex, significantly improving the electrical output performance and durability of triboelectric nanogenerators. Furthermore, the foamed copper skeleton not only serves as an electrode for electrostatic induction and charge conduction, but also acts as a structural skeleton to uniformly disperse external forces within the material, supporting the structural design of large-size TENGs and promoting the practical application of TENGs. Attached Figure Description

[0029] Figure 1 A schematic diagram illustrating the preparation process of the foamed copper skeleton-based heterogeneous material in this embodiment of the invention;

[0030] Figure 2a , Figure 2b , Figure 2c and Figure 2d The graphs show the charge transfer curves of copper foam with PPI values ​​of 20, 40, 60 and 80 combined with POM spheres of different diameters in the embodiments of the present invention.

[0031] Figure 3a , Figure 3b , Figure 3c and Figure 3d The figures are short-circuit current curves of copper foam with PPI values ​​of 20, 40, 60 and 80 combined with POM balls of different diameters in the embodiments of the present invention.

[0032] Figure 4a , Figure 4b Figure 4c and Figure 4d The figures are open-circuit voltage curves of copper foam with PPI values ​​of 20, 40, 60 and 80 combined with POM balls of different diameters in the embodiments of the present invention.

[0033] Figure 5a , Figure 5b and Figure 5cThe figures shown are the charge transfer curves, short-circuit current curves, and open-circuit voltage curves for the copper foil electrodes combined with POM spheres of different diameters in the embodiments of the present invention.

[0034] Figure 6a and Figure 6b The figures are open-circuit voltage curves for different POM ball combinations with fixed electrode materials and different electrode materials with fixed POM ball diameters, respectively, in the embodiments of the present invention.

[0035] Figure 6c and Figure 6d The figures shown are the short-circuit current curves and charge transfer curves for different electrode materials with fixed POM ball diameters in embodiments of the present invention. Detailed Implementation

[0036] Example 1

[0037] In this embodiment, the preparation method of the foamed copper framework-based heterogeneous material for triboelectric nanogenerator includes the following steps:

[0038] Step (1): Cut the foamed copper (made of T2 copper) into a preset size of 26mm×24mm×2mm. First, place it in anhydrous ethanol and clean it for 5 minutes at an ultrasonic power of 120W, an ultrasonic frequency of 40KHz, and a temperature of 35℃ to remove oil and other stains from the surface of the foamed copper. After drying, place it in 0.5mol / L dilute hydrochloric acid for a second ultrasonic cleaning at an ultrasonic power of 120W, an ultrasonic frequency of 40KHz, and a temperature of 35℃ for 5 minutes to remove impurities and oxides from the surface of the foamed copper. After the second ultrasonic cleaning, let it air dry for later use. The porosity of the foamed copper is 20PPI.

[0039] Step (2): Prepare the platinum catalytic silicone rubber liquid and place it under ultrasonic conditions (ultrasonic power 120W, ultrasonic frequency 40KHz, temperature 35℃) for the first exhaust treatment for 4 minutes; the platinum catalytic silicone rubber liquid is prepared according to the instructions for use of Ecoflex 00-50 platinum catalytic silicone rubber produced by Smooth-On, that is: mix the two components of Ecoflex platinum catalytic silicone rubber matrix and platinum catalytic silicone rubber curing agent in a mass ratio of 1:1.

[0040] Step (3): At room temperature, place the foamed copper at the bottom of the mold and slowly pour the platinum catalytic silicone rubber liquid into the foamed copper at a pouring rate of about 60 mL / min along the corner of the mold. The foamed copper pores are completely filled by the natural flow of the platinum catalytic silicone rubber liquid. The mass ratio of foamed copper to platinum catalytic silicone rubber liquid is 1:2.

[0041] Step (4): After casting, transfer the mold to ultrasonic conditions (ultrasonic power 120W, ultrasonic frequency 40KHz, temperature 35℃) for a second venting treatment for 2 minutes.

[0042] Step (5): After the second exhaust treatment, the mold is placed in a 60℃ drying oven for curing treatment for 2 hours. After the curing treatment is completed, the foam copper skeleton-based heterogeneous material for triboelectric nanogenerator is prepared.

[0043] Example 2

[0044] The only difference between this embodiment and Embodiment 1 is that the pore density of the copper foam is 40 PPI; the other raw materials, operating methods and steps, and process parameters are exactly the same as those in Embodiment 1.

[0045] Example 3

[0046] The only difference between this embodiment and Embodiment 1 is that the porosity of the copper foam is 60 PPI; the other raw materials, operating methods and steps, and process parameters are exactly the same as in Embodiment 1.

[0047] Example 4

[0048] The only difference between this embodiment and Embodiment 1 is that the pore density of the copper foam is 80 PPI; the other raw materials, operating methods and steps, and process parameters are exactly the same as those in Embodiment 1.

[0049] The four groups of foamed copper skeleton-based heterogeneous materials prepared in Examples 1, 2, 3 and 4 did not have obvious problems such as incomplete pouring or bubbles after curing.

[0050] Example 5

[0051] The copper foam framework-based heterogeneous material prepared in Example 1 was used as the 3D electrode of the triboelectric nanogenerator, and the electrical output performance of the triboelectric nanogenerator was tested. Polyoxymethylene (POM) microspheres have strong electron-donating capabilities; in this example, POM microspheres were assembled with the copper foam framework-based heterogeneous material prepared in Example 1 to prepare a triboelectric nanogenerator model.

[0052] Composition and performance testing method of triboelectric nanogenerator: POM microspheres with a diameter of 2 mm and copper foam skeleton-based heterogeneous materials were alternately placed in a 3D printed device shell, fixed on a triboelectric vibration test bench, and connected with wires and an electrometer. Under the experimental conditions of 30 mm motion amplitude and 5 Hz motion frequency, the electrical output performance of the simple triboelectric nanogenerator composed of POM microspheres and copper foam skeleton-based heterogeneous materials was tested.

[0053] Repeat the above application test by changing the diameter of the POM microspheres used to 2mm, 3mm, 4mm and 5mm.

[0054] Example 6

[0055] The foamed copper framework-based heterogeneous material prepared in Example 2 was used as the three-dimensional electrode of the triboelectric nanogenerator, and the electrical output performance of the triboelectric nanogenerator was tested. The composition of the triboelectric nanogenerator and the test method for its performance were exactly the same as those in Example 5.

[0056] Repeat the above application test by changing the diameter of the POM microspheres used to 2mm, 3mm, 4mm and 5mm.

[0057] Example 7

[0058] The foamed copper framework-based heterogeneous material prepared in Example 3 was used as the three-dimensional electrode of the triboelectric nanogenerator, and the electrical output performance of the triboelectric nanogenerator was tested. The composition of the triboelectric nanogenerator and the test method for its performance were exactly the same as those in Example 5.

[0059] Repeat the above application test by changing the diameter of the POM microspheres used to 2mm, 3mm, 4mm and 5mm.

[0060] Example 8

[0061] The foamed copper framework-based heterogeneous material prepared in Example 4 was used as the 3D electrode of the triboelectric nanogenerator, and the electrical output performance of the triboelectric nanogenerator was tested. The composition of the triboelectric nanogenerator and the test method for its performance were exactly the same as those in Example 5.

[0062] Repeat the above application test by changing the diameter of the POM microspheres used to 2mm, 3mm, 4mm and 5mm.

[0063] Comparative Example 1

[0064] Copper foil was used as the electrode of the triboelectric nanogenerator, and the electrical output performance of the triboelectric nanogenerator was tested. The composition of the triboelectric nanogenerator and the performance testing method were exactly the same as in Example 5. The above application tests were repeated by changing the diameter of the POM microspheres used to 2 mm, 3 mm, 4 mm, and 5 mm.

[0065] The electrical output performance test results of the triboelectric nanogenerators in Examples 5 to 8 and Comparative Example 1 are analyzed as follows:

[0066] like Figures 2a to 2d , Figures 3a to 3d , Figures 4a to 4dThe values ​​represent the test results of transferred charge, short-circuit current, and open-circuit voltage for combinations of 20, 40, 60, and 80 PPI copper foam with POM spheres of diameters of 2 mm, 3 mm, 4 mm, and 5 mm, respectively. Figure 5a , Figure 5b and Figure 5c These are the test results for the control group device using copper foil as electrodes.

[0067] Triboelectric nanogenerator samples using 20-80 PPI copper foam as 3D electrodes combined with POM microspheres of different diameters exhibited stable electrical output signals. The amount of transferred charge in each sample increased accordingly with the increase of the POM microsphere diameter. The samples using 5 mm diameter POM microspheres showed excellent electrical output performance. The measured instantaneous transferred charge of the copper foil control group was only 2.81 nC, while the instantaneous transferred charge of each 3D electrode sample was 6.32 nC, 8.041 nC, 6.28 nC, and 9.6 nC, respectively, showing a significant increase in transferred charge. In particular, the 80 PPI copper foam 3D electrode showed a 242% increase in transferred charge compared to the control group (copper foil). At this time, the measured open-circuit voltage and short-circuit current of the control group were 10.22 V and 41.79 nA, respectively, while the open-circuit voltage and short-circuit current of the 3D electrode constructed with 80 PPI copper foam were 29.44 V and 165.38 nA, respectively, representing increases of 188% and 296%. The three-dimensional electrode constructed with copper foam showed significant improvement in all electrical output performance tests.

[0068] In addition, this embodiment also compares the overall electrical output performance of each group of triboelectric nanogenerator samples using radar charts, such as... Figures 6a to 6d As shown. Figure 6a The 5mm diameter POM microspheres exhibited the best electrical output performance under various electrode material combinations, and the highest open-circuit voltage was obtained among different electrode materials. Figure 6b The three-dimensional electrode constructed with 80 PPI copper foam produced the maximum open-circuit voltage under test conditions with POM spheres of various diameters; simultaneously... Figure 6c and 6d The device demonstrated superior performance in terms of generated short-circuit current and transferred charge. In summary, the device composed of a 5mm diameter POM microsphere and a copper foam skeleton based on an 80PPI copper foam framework exhibits the best overall electrical output performance.

[0069] 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 the claims of this patent application.

Claims

1. A method for preparing foamed copper framework-based heterogeneous materials for triboelectric nanogenerators, characterized in that, Includes the following steps: Step (1): Cut the copper foam with a pore density of 20-80 PPI into the preset size, place it in anhydrous ethanol for a first ultrasonic cleaning, blow it dry, and then place it in dilute hydrochloric acid for a second ultrasonic cleaning. After the second ultrasonic cleaning, let it air dry for later use. Step (2): Prepare platinum catalytic silicone rubber solution and place it under ultrasonic conditions for the first exhaust treatment; Step (3): At room temperature, place the foamed copper at the bottom of the mold, and pour the platinum catalytic silicone rubber liquid obtained by mixing the platinum catalytic silicone rubber matrix and the platinum catalytic silicone rubber curing agent at a mass ratio of 1:1 into the foamed copper along the corner of the mold. The foamed copper pores are completely filled by the natural flow of the platinum catalytic silicone rubber liquid. The mass ratio of foamed copper to platinum catalytic silicone rubber liquid is 1:2-3. The pouring rate of platinum catalytic silicone rubber liquid is 40-80 mL / min. Step (4): After casting is completed, the mold is transferred to ultrasonic conditions for a second venting process. Step (5): After the second exhaust treatment is completed, the mold is placed in a drying oven for curing. After the curing treatment is completed, the foam copper skeleton-based heterogeneous material for triboelectric nanogenerator is prepared.

2. The method for preparing foamed copper framework-based heterogeneous materials for triboelectric nanogenerators according to claim 1, characterized in that, In step (1), the mass fraction of copper in the foamed copper is greater than or equal to 99.90 wt%; the time for the first ultrasonic cleaning is 3-8 min; the molar concentration of dilute hydrochloric acid is 0.3-0.7 mol / L; the time for the second ultrasonic cleaning is 3-8 min; the ultrasonic conditions for the first and second ultrasonic cleaning are the same: ultrasonic power 100-150W, ultrasonic frequency 35-45KHz, and ultrasonic temperature 30-40℃.

3. The method for preparing the foamed copper framework-based heterogeneous material for triboelectric nanogenerators according to claim 1, characterized in that, In step (2), the platinum catalytic silicone rubber solution is prepared according to the instructions for use of Ecoflex 00-50 platinum catalytic silicone rubber produced by Smooth-On; the first exhaust treatment time is 3-7 minutes; during the first exhaust treatment: ultrasonic power 100-150W, ultrasonic frequency 35-45KHz, ultrasonic temperature 30-40℃.

4. The method for preparing the foamed copper framework-based heterogeneous material for triboelectric nanogenerators according to claim 1, characterized in that, Step (4): The second exhaust treatment takes 1-2 minutes; during the second exhaust treatment: ultrasonic power 100-150W, ultrasonic frequency 35-45KHz, ultrasonic temperature 30-40℃.

5. The method for preparing a foamed copper framework-based heterogeneous material for a triboelectric nanogenerator according to claim 1, characterized in that, In step (5), the curing conditions are: curing temperature 50-70℃, curing time 1-3h, or curing at room temperature for 24h.

6. The method for preparing the foamed copper framework-based heterogeneous material for triboelectric nanogenerators according to claim 1, characterized in that, In step (1), the foamed copper is made of T2 copper with a porosity of 80 PPI; the first ultrasonic cleaning time is 5 min; the concentration of dilute hydrochloric acid is 0.5 mol / L; the second ultrasonic cleaning time is 5 min; the ultrasonic conditions for the first and second ultrasonic cleanings are the same: ultrasonic power 120 W, ultrasonic frequency 40 kHz, and ultrasonic temperature 35 °C; in step (2), the platinum catalytic silicone rubber solution is Ecoflex platinum catalytic silicone rubber produced by Smooth-On. Prepare according to the instructions for use of 00-50; the first exhaust treatment time is 4 min, ultrasonic power is 120W, ultrasonic frequency is 40KHz, and temperature is 35℃; in step (3), the mass ratio of foamed copper to platinum catalytic silicone rubber liquid is 1:2; the pouring rate of platinum catalytic silicone rubber liquid is 60mL / min; in step (4), the second exhaust treatment time is 2 min, ultrasonic power is 120W, ultrasonic frequency is 40KHz, and temperature is 35℃; in step (5), the curing conditions are: curing temperature 60℃ and curing time 2h.

7. A foamed copper framework-based heterogeneous material for triboelectric nanogenerators prepared by any one of the preparation methods described in claims 1-6, characterized in that, Using copper foam with a pore density of 20-80 PPI as the skeleton, and platinum catalytic silicone rubber liquid obtained by mixing and curing platinum catalytic silicone rubber matrix and platinum catalytic silicone rubber curing agent as the filler, the copper foam and platinum catalytic silicone rubber liquid are cured to form a three-dimensional interpenetrating structure, that is, platinum catalytic silicone rubber fills the pores of copper foam and coats the surface of copper foam.

8. The application of foamed copper framework-based heterogeneous materials for triboelectric nanogenerators, characterized in that, The copper foam framework-based heterogeneous material for triboelectric nanogenerators, prepared by the preparation method of the copper foam framework-based heterogeneous material for triboelectric nanogenerators as described in any one of claims 1-6, is used as the 3D electrode of the triboelectric nanogenerator.

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