Efficient energy harvesting method for regulating relaxation of double electric layers through giant flexoelectric effect of porous material

Abstract

The invention belongs to the field of energy harvesting methods and technologies, and particularly discloses an efficient energy harvesting method for regulating relaxation of double electric layers through a porous material giant flexoelectric effect, and the method comprises the following steps: S1, preparing an energy conversion system; and S2, a cyclic load is applied to the energy conversion system, and mechanical energy is converted into electric energy. The efficient energy harvesting method for regulating and controlling relaxation of the double electric layers through the giant flexoelectric effect of the porous material is suitable for a porous polymer composite material based on doped graphene, carbon nanotubes and other micro-nano conductive materials, and by means of the giant flexoelectric effect generated when the porous material deforms, the relaxation of the double electric layers is regulated and controlled through the giant flexoelectric effect. And ion distribution in the electrolyte solution is effectively regulated and controlled, so that the efficiency of converting mechanical energy into trapped electric energy can be improved.

Description

Technical Field

[0001] This invention belongs to the field of energy capture methods and technology, specifically relating to an efficient energy capture method for regulating double-layer relaxation by the giant flexural electrical effect of porous materials. Background Technology

[0002] Against the backdrop of the deep integration of global energy structure transformation and sustainable development strategies, energy shortages and environmental pollution have become significant challenges hindering human societal progress. Long-term over-reliance on traditional fossil fuels not only accelerates the risk of resource depletion, but the greenhouse gases and pollutants produced by their combustion also cause irreversible damage to the ecological environment. Therefore, developing clean, efficient, and sustainable new energy capture technologies has become a research hotspot in the global scientific and technological field. Mechanical energy, as one of the most widely distributed forms of energy in nature, is widely present in various sources such as human movement, ocean waves, industrial vibrations, and environmental noise. Efficiently converting this mechanical energy into electrical energy is of great significance for alleviating energy pressure and promoting the development of emerging fields such as the Internet of Things and wearable devices.

[0003] Flexoelectricity, a typical mechanoelectric coupling mechanism, refers to the phenomenon of polarization occurring in materials during non-uniform deformation processes such as bending and torsion. This effect is independent of the material's centrosymmetry and is particularly pronounced at the micro- and nanoscale, providing a new technological path for mechanical energy to electrical energy conversion. In recent years, flexoelectric energy conversion technology has shown broad application potential in scenarios such as powering microelectronic devices and self-driven sensors due to its advantages of not being limited by material symmetry or Curie temperature, and not requiring high-voltage polarization treatment. However, this technology still faces many bottlenecks that limit its practical application and industrialization process.

[0004] Currently, flexure electrokinetic energy harvesting technology is mainly based on macroscopic solid materials, with a single deformation mode and limited flexure polarization intensity, resulting in generally low conversion efficiency of mechanical energy to electrical energy. In contrast, porous structures contain a large number of micro / nanoscale ligaments, which can generate significant flexure polarization under arbitrary loads, exhibiting omnidirectional response and enhancement effects. Although the energy conversion efficiency of the flexure electrokinetic effect of porous structures is now comparable to that of commercial piezoelectric materials, the rapid development of emerging fields and the increasing demand for clean energy have placed higher demands on the energy conversion efficiency of energy harvesting systems. For example, products such as IoT sensors, wireless communication devices, microelectromechanical systems (MEMS), and wearable health monitoring devices often require miniaturized, low-power, and long-lasting power supply modules, which requires energy harvesting devices to achieve high energy density and high conversion efficiency within a limited volume.

[0005] However, existing flexural electrokinetic energy harvesting methods based on porous materials primarily rely on the material's own flexural polarization, failing to fully utilize the synergistic gain effects generated by the interaction between the porous structure and its surrounding environment. This results in the electrical output of the energy harvesting system being insufficient to meet the actual power supply requirements of the aforementioned devices, making it impossible for most self-powered systems to break free from their dependence on traditional batteries, thus limiting the portability and lifespan of the products. Therefore, there is a need in this field to develop an efficient energy harvesting method that can effectively solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide an efficient energy harvesting method for regulating double-layer relaxation by the giant flexure electrical effect of porous materials. This method is applicable to porous polymer composite materials based on micro- and nano-conductive materials such as doped graphene and carbon nanotubes. By utilizing the giant flexure electrical effect generated when porous materials are deformed, the ion distribution in the electrolyte solution can be effectively regulated, thereby improving the efficiency of converting mechanical energy into harvestable electrical energy.

[0007] To achieve the above objectives, this invention provides an efficient energy harvesting method for controlling the relaxation of the electric double layer by the giant flexural electrical effect in porous materials, comprising the following steps: Step S1: Prepare the energy conversion system; A. Coat the upper surface of a porous material with a giant flexural electrical effect with an insulating layer. Connect the lower surface of the porous material to a wire. Coat the upper surface of the insulating layer with an electrode. Connect the electrode to the wire. Connect the two wires to an electrical appliance or a voltage / current meter. B. Conductive micro- and nano-materials are doped into the ligaments of porous materials with giant flexural electrical effects to form a conductive network, and the wires are connected to the conductive micro- and nano-materials. C. Immersing a porous material with a giant flexural effect into an electrolyte solution yields an energy conversion system with a closed energy-harvesting loop; Step S2: Apply a cyclic load to the energy conversion system to efficiently convert mechanical energy into electrical energy; By utilizing the giant flexural electrical effect generated by the cyclic deformation of porous materials, charged ions in the electrolyte solution are driven to form a dynamically relaxed double-layer structure near the conductive network on the surface of the porous material's ligaments. This converts mechanical energy into electrical energy, which is then collected by electrodes and transmitted through a closed energy-harvesting loop, thus achieving the capture of electrical energy.

[0008] Preferably, in step S1, the porous material with giant flexural electrical effect is a conductive polymer-based porous composite material, including porous polydimethylsiloxane, etc.; the conductive micro / nano materials include graphene, carbon nanotubes, silver nanowires, graphite, iron powder, aluminum powder, etc. The doping amount of the conductive micro / nano materials is adjusted according to the required conductivity and flexural properties.

[0009] Preferably, in step S1, the wire can be any conductive material, including copper wire, silver wire, etc.; the insulating layer can be any non-conductive material, including a matrix material with a porous material having a giant flexural effect, etc.; the thickness of the insulating layer is 0.1 micrometer to 100 micrometers; the electrode includes copper foil electrode, silver electrode, etc.

[0010] Preferably, in step S1, the electrolyte solution includes seawater, tap water, acid / alkali / salt solutions of different concentrations, etc.

[0011] Preferably, in step S1, the electrical signal of the energy conversion system is controlled by the flexural polarization intensity generated by the porous material with giant flexural polarization effect. When the flexural polarization intensity generated by the porous material increases, the electrical output of the system also increases.

[0012] Preferably, in step S2, the porous material with giant flexural electrical effect undergoes flexural polarization of its ligaments during cyclic deformation, resulting in a specific polarity in the conductive network on the ligament surface.

[0013] Preferably, in step S2, the conductive network on the ligament surface attracts charged ions in the electrolyte solution to form a solid / liquid interface double layer structure.

[0014] Preferably, in step S2, the solid / liquid interface double layer structure is always in a relaxation process due to the dynamic change of flexural polarization intensity, resulting in an imbalance between diffusion current and migration current, and generating a net current.

[0015] This invention employs the above-mentioned efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect of porous materials, and its beneficial effects are as follows: (1) By combining the flexural polarization phenomenon of porous materials with the double-layer structure in electrolyte solutions, this invention not only significantly improves energy conversion efficiency but also exhibits excellent stability and flexibility, allowing for flexible adjustments based on actual needs. For example, by adjusting the doping amount and porosity of the conductive phase inside the porous material, its conductivity and flexural properties can be optimized; by selecting different electrolyte solutions, it can adapt to different working environments and conditions.

[0016] (2) The energy conversion system designed in this invention also features environmental protection and energy saving, and is easy to integrate and expand, providing new ideas for the development and application of new energy capture technologies, and can achieve efficient, stable and environmentally friendly energy conversion. In addition, the electrical signal generated by the energy conversion system provided by this method is controlled by the flexural polarization generated by the material, which can bring new methods and technical approaches to the field of clean energy capture.

[0017] (3) The efficient energy harvesting method and the energy conversion system provided in this invention are applicable to various occasions that require efficient energy conversion, including but not limited to wearable devices, Internet of Things sensors, wireless communication devices, microelectromechanical systems and various microelectronic devices.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the energy conversion system in an embodiment of the efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect of porous materials according to the present invention. Figure 2 This is a diagram illustrating the electrical signal generation mechanism of the energy conversion system in an embodiment of the efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect of porous materials according to the present invention.

[0020] Figure Labels 1. Porous materials; 2. Electrolyte solutions; 3. Charged ions; 4. Ligaments; 5. Electrodes; 6. Insulating layers; 7. Wires; 8. Voltage / current meters; 9. Flexural polarization. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0023] Example like Figures 1-2 As shown, an efficient energy harvesting method for controlling double-layer relaxation using the giant flexural electrical effect in porous materials includes the following steps: Step S1: Prepare the energy conversion system; A. Coat the upper surface of a 2cm×2cm×1cm (length×width×height) porous polydimethylsiloxane / carbon nanotube composite material with a polydimethylsiloxane layer. The polydimethylsiloxane layer is an insulating layer 6, and its lower surface is connected to a copper wire, which is a conductor 7. Coat a flexible silver electrode 5 on the upper surface of the polydimethylsiloxane layer. The flexible silver electrode 5 is connected to the copper wire, and the two copper wires are connected to a voltage / current meter 8. B. The porous polydimethylsiloxane ligament 4 is doped with carbon nanotubes with a volume fraction of 4.5% to form a conductive network, and the copper wire is connected to the carbon nanotube conductive network. C. Immerse porous polydimethylsiloxane in 0.01 In a sodium chloride solution, an energy conversion system with a closed energy-harvesting loop is obtained; Step S2: Apply a peak strain of 50 to the energy conversion system. Cyclic compression loads enable the efficient conversion of mechanical energy into electrical energy; Specifically, the electrical signal of the energy conversion system is regulated by the flexural electrical signal generated by porous polydimethylsiloxane exhibiting a giant flexural electrical effect. When the intensity of the flexural polarization 9 generated by the porous polydimethylsiloxane increases, the system's electrical output also increases. During cyclic deformation, the ligaments 4 of the porous polydimethylsiloxane generate flexural polarization 9, and the carbon nanotube conductive network exposed in the electrolyte exhibits a specific polarity. The conductive network on the surface of the ligaments 4 forms a solid / liquid interfacial electric double layer structure in the electrolyte solution 2. Due to the dynamic changes in the intensity of the flexural polarization 9, the solid / liquid interfacial electric double layer structure is always in a relaxation process, leading to an imbalance between diffusion current and migration current, resulting in a net current.

[0024] This embodiment utilizes the giant flexural effect generated by the porous material 1 during cyclic deformation to drive the charged ions 3 in the electrolyte solution 2 to form a dynamically relaxed double-layer structure around the interface between the conductive network and the electrolyte solution 2, converting mechanical energy into electrical energy. This electrical energy is then transmitted through the conductive network doped inside the porous material 1, the flexible silver electrode 5, and the closed loop, thus achieving the capture of mechanical energy.

[0025] Energy harvesting tests were performed on this embodiment: The energy harvesting system prepared in this embodiment is applied at a frequency of 1. Peak strain is 50 Macroscopic compression was observed, and the short-circuit current was measured to be approximately 10. This value is more than 100 times that of the same porous material 1 in air, and more than 1,000,000 times that of pure solid polydimethylsiloxane.

[0026] Therefore, the present invention employs the above-mentioned efficient energy harvesting method for regulating double-layer relaxation by the giant flexure electrical effect of porous materials. This method is applicable to porous polymer composite materials based on micro- and nano-conductive materials such as doped graphene and carbon nanotubes. By utilizing the giant flexure electrical effect generated when porous materials are deformed, the ion distribution in the electrolyte solution can be effectively regulated, thereby improving the efficiency of converting mechanical energy into harvestable electrical energy.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A highly efficient energy harvesting method for controlling double-layer relaxation using the giant flexural electrical effect in porous materials, characterized in that, Includes the following steps: Step S1: Prepare the energy conversion system; A. Coat the upper surface of a porous material with a giant flexural electrical effect with an insulating layer. Connect the lower surface of the porous material to a wire. Coat the upper surface of the insulating layer with an electrode. Connect the electrode to the wire. Connect the two wires to an electrical appliance or a voltage / current meter. B. Conductive micro- and nano-materials are doped into the ligaments of porous materials to form a conductive network, and the wires are connected to the conductive micro- and nano-materials. C. Immersing porous materials in an electrolyte solution yields an energy conversion system with a closed energy-harvesting loop; Step S2: Apply a cyclic load to the energy conversion system to convert mechanical energy into electrical energy; By utilizing the giant flexural electrical effect generated by the cyclic deformation of porous materials, charged ions in the electrolyte solution are driven to form a dynamically relaxed double-layer structure near the conductive network on the surface of the porous material's ligaments. This converts mechanical energy into electrical energy, which is then collected by electrodes and transmitted through a closed energy-harvesting loop, thus achieving the capture of electrical energy.

2. The efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect in porous materials according to claim 1, characterized in that: In step S1, the porous material is a conductive polymer-based porous composite material, including porous polydimethylsiloxane; the conductive micro / nano materials include graphene, carbon nanotubes, silver nanowires, graphite, iron powder, and aluminum powder. The doping amount of the conductive micro / nano materials is adjusted according to the required conductivity and flexural properties.

3. The efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect in porous materials according to claim 1, characterized in that: In step S1, the wire is a conductive material, including copper wire and silver wire; the insulating layer is a non-conductive material, including a matrix material with a porous material having a giant flexural effect; the thickness of the insulating layer is 0.1 micrometer to 100 micrometers; the electrodes include copper foil electrodes and silver electrodes.

4. The efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect in porous materials according to claim 1, characterized in that: In step S1, the electrolyte solution includes seawater, tap water, and acid / alkali / salt solutions of different concentrations.

5. The efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect in porous materials according to claim 1, characterized in that: In step S1, the electrical signal of the energy conversion system is modulated by the flexural polarization generated by the porous material.

6. The efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect in porous materials according to claim 1, characterized in that: In step S2, the porous material with giant flexural electrical effect undergoes flexural polarization of its ligaments during cyclic deformation, which makes the conductive network on the ligament surface polarized.

7. The efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect in porous materials according to claim 6, characterized in that: In step S2, the conductive network on the ligament surface attracts charged ions in the electrolyte solution to form a solid / liquid interface double layer structure.

8. The efficient energy harvesting method for controlling double-layer relaxation by the giant flexural electrical effect in porous materials according to claim 7, characterized in that: In step S2, the solid / liquid interface double layer structure is always in a relaxation process due to the dynamic change of flexural polarization intensity, which leads to an imbalance between diffusion current and migration current, resulting in a net current.

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