A frictional power generation material, a frictional power generator and applications thereof

Abstract

The application discloses a friction power generation material, and a preparation method thereof. The preparation method comprises the following steps: partially immersing a foamed metal into a resin solution, taking out and air-drying, then coating the resin solution on the surface of the foamed metal around which the resin is solidified, and heating and drying, so as to obtain the friction power generation material. The resin solution comprises polydimethylsiloxane and a curing agent. The application further discloses a friction power generator, which comprises a positive electrode and a negative electrode. The positive electrode is obtained by fixing a metal plate on the surface of the foamed metal of the friction power generation material without the resin solidified. The negative electrode is obtained by fixing a metal plate around the foamed metal of the same friction power generation material with the resin solidified. The friction power generator can convert sound energy into electric energy, and realize sound energy power generation.

Description

Technical Field

[0001] This invention belongs to the field of triboelectric power generation, and particularly relates to a triboelectric power generation material, a triboelectric generator, and their applications. Background Technology

[0002] Since 2014, wearable technology, by integrating technologies from the information and materials fields and combining them with mobile internet and various big data platforms, has become an emerging data traffic portal by collecting and further processing information on human movement, health, and physiological conditions. Wearable electronic devices refer to electronic products that can be directly worn on the human body or integrated into clothing. Sensors, as the core of wearable technology devices, convert physiological signals from the human body or external environmental signals into electrical signals, thus providing an interface for information transmission between the human body and electronic information systems. However, most wearable sensors still use traditional external batteries to power their operation. Traditional energy sources are not environmentally friendly due to their large size and weight, and the linear relationship between battery capacity and weight poses a significant challenge to the miniaturization of sensor components, failing to meet the comfort and durability requirements of wearable devices. Therefore, for the sensors of wearable products, having a self-generating power signal capable of effectively maintaining their operation is crucial.

[0003] In 2012, Professor Wang Zhonglin's team first proposed the concept of triboelectric nanogenerators (TENGs). A TENG is a device driven by Maxwell's displacement current, capable of collecting low-frequency, minute mechanical energy from the external environment and converting it into electrical energy. It has wide applications and advantages such as high output stability, cost-effectiveness, cleanliness, environmental friendliness, and ease of fabrication. It can also enable sensors to generate their own power without external input, showing broad application prospects in micro-energy harvesting in wearable devices. Current triboelectric generators are based on external mechanical forces that deform materials through compression and stretching, thereby generating electrons. However, in recent years, the rapid development of technologies such as wireless communication, functional materials, electronic information, and microelectromechanical systems (MEMS) has led to a surge in research interest in diverse power generation modes (triboelectric generators convert different forms of energy, such as heat and sound, into electrical energy). This has placed new demands on the structure of triboelectric generators. Summary of the Invention

[0004] Based on the above-mentioned technical problems, the present invention provides a triboelectric material, a triboelectric generator and its application. The triboelectric generator can convert sound energy into electrical energy, realize sound energy power generation, and is expected to be applied in wearable products to meet their self-powering needs.

[0005] The specific solution of this invention is as follows:

[0006] One objective of this invention is to provide a triboelectric material, the preparation method of which includes: immersing a foamed metal portion in a resin solution, removing it and drying it, then coating the surface of the foamed metal with the resin that has been cured around it with another resin solution, and heating and drying it to obtain the triboelectric material; the resin solution includes polydimethylsiloxane and a curing agent.

[0007] In this invention, "partial immersion" means that a portion of the foamed metal is immersed in the resin solution, while another portion of the foamed metal remains uncontacted. There is no specific limitation on the amount immersed; preferably, at least 0.1 cm of the foamed metal is kept unimmersed. For example, for cuboid / cube-shaped foamed metal, where the length and width are denoted as a and b respectively, in a preferred embodiment, at least (a × b × 0.1 cm) of the foamed metal volume is not immersed in the resin solution.

[0008] In this invention, "around" refers to all surfaces other than the top and bottom surfaces of the foam metal.

[0009] There is no specific limitation on the coating thickness; preferably, the coating thickness is ≥0.05cm; more preferably, the coating thickness is 0.05-0.2cm.

[0010] There are no specific limitations on the type of curing agent, including but not limited to dibutyl phthalate.

[0011] Preferably, the foam metal is selected from one of foam nickel, foam copper, and foam silver.

[0012] Preferably, the foam metal is prepared by chemical plating, which includes: activating a porous polymer, immersing the activated porous polymer in a metal ion ligand solution, and then immersing it in a reducing agent solution to obtain a foam metal precursor; calcining the foam metal precursor and cooling it to obtain the foam metal.

[0013] The metal ion ligand solution described in this invention refers to a mixed solution containing metal ions and a ligand; for example, when preparing nickel foam, the selection of the metal ion ligand solution includes, but is not limited to, a mixed solution of nickel sulfate and trisodium citrate.

[0014] The present invention can adjust the shape and size of the foam metal by adjusting the shape and size of the porous polymer.

[0015] Preferably, the porous polymer is immersed in an activation solution at 95-105°C for 0.5-1.5 hours; the activation solution includes polyvinyl alcohol and metal activation ions; the metal activation ions are selected from at least one of silver ions, palladium ions, and nickel ions; preferably, the activation is carried out under ultrasonic conditions.

[0016] This invention employs a separate immersion and reduction process during chemical plating, and uses ultrasound to enable the metal ion ligand solution and activation solution to fully contact the interior of the porous polymer template, thereby achieving the deposition of metal particles in various pores inside the porous polymer. This results in a foam metal with a large number of interconnected pores that penetrate deep into the material and exhibit excellent electrical conductivity.

[0017] Preferably, the porous polymer is selected from at least one of polyurethane foam, ethylene-vinyl acetate copolymer foam, and polyethylene foam; the polyvinyl alcohol type is 1799; in the activation solution, the polyvinyl alcohol content is 5-100 g / L, and the metal activation ion content is 0.1-20 g / L.

[0018] This invention uses polyvinyl alcohol of type 1799, which is soluble in water above 95°C. Based on the adsorption of metal activated ions by hydroxyl groups in polyvinyl alcohol and the film-forming ability of polyvinyl alcohol, the metal activated ions are adsorbed on the surface of the pores inside the porous polymer material, avoiding the pollution caused by traditional etching and oxidation processes.

[0019] Preferably, the metal ion ligand solution is selected from at least one of nickel ion, copper ion, and silver ion ligand solutions; the concentration of the metal ion ligand solution is 70-100 g / L; the temperature of the metal ion ligand solution is 60-80℃; preferably, the reducing agent is sodium hypophosphite or formaldehyde, and the temperature of the reducing agent solution is 30-50℃.

[0020] Preferably, during calcination, a high-melting-point material with a melting point higher than that of the porous polymer is placed on the surface of the foam metal precursor; the high-melting-point material is selected from alumina ceramic plates or stainless steel plates.

[0021] This invention avoids unevenness and warping at both ends in the prepared triboelectric material by placing high-melting-point materials such as alumina ceramic plates or stainless steel plates on the surface of the calcined foam metal precursor.

[0022] The calcination atmosphere and temperature should be designed to prevent chemical changes in the deposited metal particles. The calcination temperature should allow for complete combustion, carbonization, and volatilization of the porous polymer template. No specific limitation is made on the calcination time; preferably, it is 0.5-5 hours.

[0023] Preferably, the mass ratio of polydimethylsiloxane to curing agent in the resin solution is 17-40:1.

[0024] The second objective of this invention is to provide a triboelectric generator, comprising a positive electrode and a negative electrode; the positive electrode is obtained by fixing a metal plate to the surface of a foamed metal material that has not been cured with resin; the negative electrode is obtained by fixing a metal plate around the same triboelectric material with a resin-cured foamed metal.

[0025] The third objective of this invention is to provide the application of the above-mentioned triboelectric materials or triboelectric generators in sound energy power generation, converting sound energy into electrical energy and realizing sound energy power generation.

[0026] The triboelectric material / triboelectric generator of this invention can convert sound energy into electrical energy. The mechanism for realizing sound energy power generation is as follows:

[0027] When sound waves strike the surface of a porous foam metal material and penetrate into its interior, they cause the air in the gaps between the metal to vibrate. The relative motion between the air and the metal wall, along with the viscosity of the air itself, converts the kinetic energy generated by the air vibration into the vibration of the metal layer, thus consuming the sound energy. In addition, after being reflected by the rigid wall, the sound waves return to the surface of the porous foam metal material. Some of the sound waves are reflected back into the air, while some are consumed by the porous foam metal material. Through this repeated propagation, the sound waves continuously convert and dissipate energy until the sound is absorbed.

[0028] In other words, sound is gradually converted into vibration of the metal layer during transmission inside the triboelectric generator. Due to the difference in elastic modulus between the metal layer and the polydimethylsiloxane layer, it is further converted into vibration between the interface of the metal layer and the polydimethylsiloxane layer. Due to the difference in electron affinity between the two, combined with the design of the device's external structure, the polydimethylsiloxane layer gains a large number of electrons and conducts them out, thus realizing sound power generation. Attached Figure Description

[0029] Figure 1 This is a flowchart of the triboelectric power generation material and triboelectric generator preparation process in Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the triboelectric power generation material and triboelectric generator of Embodiment 1 of the present invention; Detailed Implementation

[0031] The technical solution of the present invention will be described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0032] Example 1

[0033] A triboelectric material is prepared according to the following method:

[0034] S1. Immerse the nickel foam portion in a resin solution composed of PDMS resin and dibutyl phthalate curing agent, wherein the mass ratio of polydimethylsiloxane to dibutyl phthalate is 20:1. Leave one side of the nickel foam with a height of 0.1cm unimmersed in the resin solution (one 11×8cm surface). Remove and hang to dry.

[0035] Among them, the nickel foam is a cuboid with dimensions (length × width × height) of 11 × 8 × 2 cm;

[0036] S2. Apply a 0.05cm thick layer of resin solution to the surface of the nickel foam that has been cured with resin, and then place it in an oven and heat it at 80°C for 1 hour to obtain the triboelectric material.

[0037] Among them, the nickel foam is prepared by chemical plating, specifically:

[0038] (1) Preparation of foam metal precursor: Cleaned and degreased porous polyurethane foam was used as a template and immersed in an activation solution at 100°C. The activation solution was ultrasonically activated for 1 hour at room temperature. The activation solution was a mixed solution of 10 g / L polyvinyl alcohol 1799 and 0.1 g / L palladium chloride, and the pH was adjusted to 2 with hydrochloric acid.

[0039] Remove the activated porous polyurethane foam, rinse with deionized water, hang to air dry at room temperature, dry in air at 100°C, and then impregnate under ultrasonic conditions with a high concentration of 100g / L Ni at 60°C. 2+ The ligand solution was then immersed in a 10 g / L sodium hypophosphite solution at 40 °C, and the pH was adjusted to 10 using sodium hydroxide to obtain the foam metal precursor.

[0040] (2) Calcination: The foamed metal precursor was calcined at 390℃ for 3 hours in air atmosphere. During the calcination process, a 3g / cm³ piece of material was placed on the surface of the polymer template for depositing metal particles. 2 The alumina ceramic plate is calcined, and the porous polymer template is completely burned, carbonized and volatilized during the calcination process. It is then cooled in the furnace to obtain nickel foam.

[0041] A triboelectric generator includes a positive electrode and a negative electrode. The positive electrode is obtained by fixing a copper plate to the surface of a foamed metal material that has not been cured with resin. The negative electrode is obtained by fixing copper plates to the periphery (two 11×2cm surfaces and two 8×2cm surfaces) of the same foamed metal material with cured resin. During the installation of the copper plates, contact between the positive and negative copper plates must be avoided.

[0042] The process flow diagram for the preparation of triboelectric materials and triboelectric generators corresponding to this embodiment is as follows: Figure 1 As shown.

[0043] The structural schematic diagram of the triboelectric material and triboelectric generator corresponding to this embodiment is shown below. Figure 2 As shown.

[0044] Application Example 1

[0045] Using the triboelectric material and the prepared triboelectric generator corresponding to this embodiment for acoustic energy generation can convert acoustic energy into electrical energy, thus realizing acoustic energy generation.

[0046] Specific application method: Use a loudspeaker as the sound source, with the loudspeaker facing the side of the copper plate that is not fixed. The distance between the triboelectric generator and the loudspeaker is 25cm. The positive and negative leads are connected to an oscilloscope.

[0047] Test results: When the sound source is 60, 80, 100, and 120 dB, the output voltage of the triboelectric generator is 1.3, 3.3, 5.6, and 9.8 V, respectively, indicating that the triboelectric generator prepared by this invention can realize sound energy power generation.

[0048] Example 2

[0049] A triboelectric material is prepared according to the following method:

[0050] S1. Immerse the copper foam portion in a resin solution composed of PDMS resin and dibutyl phthalate curing agent, wherein the mass ratio of polydimethylsiloxane to dibutyl phthalate is 30:1. Leave one side of the copper foam with a height of 0.18cm unimmersed in the resin solution (one 9×9cm surface). Remove and hang to dry.

[0051] Among them, the foamed copper is a cube with a size of 9×9×9cm;

[0052] S2. Apply a 0.1cm thick layer of resin solution to the surface of the foamed copper that has been cured with resin, and then place it in an oven and heat it at 60℃ for 3 hours to obtain the triboelectric material.

[0053] The foamed copper is prepared using a chemical plating method, specifically:

[0054] (1) Preparation of foam metal precursor: The cleaned and degreased porous ethylene-vinyl acetate copolymer foam was immersed in an activation solution at 100℃ and activated by ultrasonic assistance at room temperature for 1h; wherein, the activation solution was a mixed solution of 20g / L polyvinyl alcohol 1799 and 0.2g / L palladium chloride, and the pH was adjusted to 2 with hydrochloric acid.

[0055] Remove the activated ethylene-vinyl acetate copolymer foam, rinse with deionized water, hang to air dry at room temperature, dry in air at 100°C, and then immerse in a high-concentration (80 g / L) Cu solution at 70°C under ultrasonic conditions. 2+ The ligand solution was then immersed in a 12 g / L sodium hypophosphite solution at 50 °C, and the pH was adjusted to 10 with sodium hydroxide to obtain the foam metal precursor.

[0056] (2) Calcination: The foamed metal precursor was calcined at 650℃ for 4 hours under a nitrogen atmosphere. During the calcination process, a 5g / cm³ piece of material was placed on the surface of the polymer template for depositing metal particles. 2 The stainless steel plate is calcined, and the porous polymer template is completely burned, carbonized and volatilized during the calcination process. Then it is cooled with the furnace to obtain foamed copper.

[0057] A triboelectric generator includes: a positive electrode and a negative electrode; wherein: the positive electrode is obtained by fixing a copper plate to the surface of a foamed metal material that has not been cured with resin; the negative electrode is obtained by fixing a copper plate to the same surface of a foamed metal material (four 9×9cm surfaces) that has been cured with resin.

[0058] Application Example 2

[0059] Using the triboelectric material and the prepared triboelectric generator corresponding to this embodiment for acoustic energy generation can convert acoustic energy into electrical energy, thus realizing acoustic energy generation.

[0060] Specific application method: Use a loudspeaker as the sound source, with the loudspeaker facing the side of the copper plate that is not fixed. The distance between the triboelectric generator and the loudspeaker is 20cm. Connect the positive and negative leads to the oscilloscope.

[0061] Test results: When the sound source is 50, 70, 90, and 110 dB, the output voltage of the triboelectric generator is 1.3, 3.3, 5.6, and 9.8 V, respectively, indicating that the triboelectric generator prepared by this invention can realize sound energy power generation.

[0062] Example 3

[0063] A triboelectric material is prepared according to the following method:

[0064] S1. Immerse the copper foam portion in a resin solution composed of PDMS resin and dibutyl phthalate curing agent, wherein the mass ratio of polydimethylsiloxane to dibutyl phthalate is 40:1. Leave one side of the copper foam with a height of 0.11cm unimmersed in the resin solution (circular side), then remove and hang to dry.

[0065] Among them, the foam copper is 3cm high and the bottom is a circle with a diameter of 11cm;

[0066] S2. Apply a 0.08cm thick layer of resin solution to the surface of the foamed copper that has been cured with resin, and then place it in an oven and heat it at 66℃ for 2 hours to obtain the triboelectric material.

[0067] The foamed copper is prepared using a chemical plating method, specifically:

[0068] (1) Preparation of foam metal precursor: Cleaned and degreased polyethylene foam was used as a template and immersed in an activation solution at 100°C. The activation solution was ultrasonically activated at room temperature for 0.8 h. The activation solution was a mixed solution of 11 g / L polyvinyl alcohol 1799 and 10 g / L silver nitrate.

[0069] Remove the activated polyethylene foam, rinse with deionized water, hang to air dry at room temperature, dry at 100°C in air, and then immerse it in a high-concentration Cu solution (70 g / L) at 70°C under ultrasonic conditions. 2+The ligand solution was then immersed in a 11 g / L formaldehyde solution at 32°C, and the pH was adjusted to 11 using sodium hydroxide to obtain the foam metal precursor.

[0070] (2) Calcination: The foamed metal precursor was calcined at 700℃ for 6 hours under a nitrogen atmosphere. During the calcination process, a 5g / cm³ piece of material was placed on the surface of the polymer template for depositing metal particles. 2 The stainless steel plate is calcined, and the porous polymer template is completely burned, carbonized and volatilized during the calcination process. The foamed copper is obtained by cooling it in the furnace.

[0071] A triboelectric generator includes a positive electrode and a negative electrode; wherein: the positive electrode is obtained by fixing a copper plate to the circular surface of a foam metal without resin curing in the triboelectric material; the negative electrode is obtained by fixing a copper plate to the periphery (cylindrical surface) of the same foam metal with resin curing in the triboelectric material.

[0072] Application Example 3

[0073] Using the triboelectric material and the prepared triboelectric generator corresponding to this embodiment for acoustic energy generation can convert acoustic energy into electrical energy, thus realizing acoustic energy generation.

[0074] Specific application method: Use a loudspeaker as the sound source, with the loudspeaker facing the circular surface of the unfixed copper plate. The distance between the triboelectric generator and the loudspeaker is 11cm, and the positive and negative leads are connected to an oscilloscope.

[0075] Test results: When the sound source is 50, 70, 90, and 110 dB, the output voltage of the triboelectric generator is 2.2, 4.3, 7.8, and 10.1 V, respectively, indicating that the triboelectric generator prepared by this invention can realize sound energy power generation.

[0076] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A triboelectric power generation material, characterized in that, The preparation method includes: immersing a foamed metal portion in a resin solution, removing it and drying it, then coating the surface of the foamed metal with the resin cured around it with another resin solution, and heating and drying it to obtain the triboelectric material; the resin solution includes polydimethylsiloxane and a curing agent; The phrase "partially immersed in resin" means that a portion of the foamed metal is immersed in the resin solution, while another portion of the foamed metal is not in contact with the resin solution.

2. The triboelectric material according to claim 1, characterized in that, The foam metal is selected from one of foam nickel, foam copper, and foam silver.

3. The triboelectric material according to claim 1 or 2, characterized in that, The foam metal is prepared by chemical plating, which includes: activating a porous polymer, immersing the activated porous polymer in a metal ion ligand solution, and then immersing it in a reducing agent solution to obtain a foam metal precursor; calcining the foam metal precursor and cooling it to obtain the foam metal.

4. The triboelectric material according to claim 3, characterized in that, The porous polymer is immersed in an activation solution at 95-105℃ for 0.5-1.5 hours; the activation solution includes polyvinyl alcohol and metal activation ions; the metal activation ions are selected from at least one of silver ions, palladium ions, and nickel ions.

5. The triboelectric material according to claim 3, characterized in that, The activation was performed under ultrasonic conditions.

6. The triboelectric material according to claim 4, characterized in that, The porous polymer is selected from at least one of polyurethane foam, ethylene-vinyl acetate copolymer foam, and polyethylene foam; the polyvinyl alcohol type is 1799; in the activation solution, the polyvinyl alcohol content is 5-100 g / L, and the metal activation ion content is 0.1-20 g / L.

7. The triboelectric material according to claim 3, characterized in that, The metal ion ligand solution is selected from at least one of nickel ion, copper ion, and silver ion ligand solutions; the concentration of the metal ion ligand solution is 70-100 g / L; and the temperature of the metal ion ligand solution is 60-80℃.

8. The triboelectric material according to claim 3, characterized in that, The reducing agent is sodium hypophosphite or formaldehyde, and the temperature of the reducing agent solution is 30-50℃.

9. The triboelectric material according to claim 3, characterized in that, During calcination, a high-melting-point material with a melting point higher than that of the porous polymer is placed on the surface of the foam metal precursor; the high-melting-point material is selected from alumina ceramic plates or stainless steel plates.

10. The triboelectric material according to claim 1, characterized in that, In the resin solution, the mass ratio of polydimethylsiloxane to curing agent is 17-40:

1.

11. A triboelectric generator, characterized in that, It includes a positive electrode and a negative electrode; the positive electrode is obtained by fixing a metal plate to the surface of a foam metal in which the triboelectric material described in any one of claims 1-10 has not been cured with resin; the negative electrode is obtained by fixing a metal plate around the foam metal in which the same triboelectric material has been cured with resin.

12. The application of the triboelectric material according to any one of claims 1-10 or the triboelectric generator according to claim 11 in acoustic power generation, characterized in that, Converting sound energy into electrical energy to achieve sound energy power generation.

Images