Fiber bundle composite, omnidirectional chemo-mechanical energy harvester comprising same, and method of fabricating same

Abstract

The present invention discloses a fiber bundle composite, an omnidirectional chemomechanical energy harvester comprising the same, and a method for manufacturing the same. The fiber bundle composite of the present invention comprises a fiber bundle including porous fibers; and carbon nanotubes (CNTs) coated on said porous fibers. The energy harvester comprising the fiber bundle composite of the present invention has excellent electrochemical properties and can be manufactured through a simple process. Furthermore, by compressing or stretching said fiber bundle composite in any one of the omnidirectional directions, the energy harvester can convert mechanical energy into electrical energy to receive energy from all directions and has the effect of being usable in a liquid environment.

Description

Technology Field

[0001] The present invention relates to a fiber bundle composite, an omnidirectional chemomechanical energy harvester comprising the same, and a method for manufacturing the same. Background Technology

[0002] Recently, with the emergence of issues such as the depletion of fossil fuels, environmental pollution, and increasing energy demand, there is a growing need for the development of alternative energy sources that move beyond existing energy generation systems. Consequently, interest in energy harvesting—which converts wasted energy found in our surroundings into useful electrical energy—is rising as a technology for developing alternative energy. In particular, intensive research is being conducted on energy harvesters designed for use within liquids, such as the ocean; representative examples include the liquid-solid triboelectric nanogenerator (LS-TENG) and the chemo-mechanical energy harvester. However, the energy harvesters studied share a common limitation in that the direction of external energy reception is restricted to a single direction, and the direction of energy supply in natural environments changes randomly over time and is difficult to predict.

[0003] Therefore, there is a need to develop an energy harvester capable of receiving energy in all directions. Prior art literature

[0004] Korean Patent Publication No. 10-2023-0060017 (May 4, 2023) The problem to be solved

[0005] The object of the present invention is to provide a fiber bundle composite that can be used in an omnidirectional chemo-mechanical energy harvester.

[0006] Another objective of the present invention is to provide an omnidirectional chemo-mechanical energy harvester using a fiber bundle composite. means of solving the problem

[0007] According to one aspect of the present invention, a fiber bundle composite is provided comprising: a fiber bundle comprising porous fibers; and carbon nanotubes (CNTs) coated on said porous fibers.

[0008] In addition, the above fiber bundle composite may be intended for use in a chemo-mechanical energy harvester.

[0009] In addition, the above-mentioned chemomechanical energy harvester is a device that produces electrical energy based on changes in the electrochemical double layer within an electrolyte due to external pressure.

[0010] In addition, the fiber bundle may be in the shape of any one selected from the group consisting of a sphere, a cube, a rectangular prism, a cylinder, a polygonal prism, and combinations thereof, preferably a sphere.

[0011] In addition, the diameter of the fiber bundle may be 10 to 50 mm.

[0012] In addition, the carbon nanotube (CNT) may include one or more types selected from the group consisting of single-walled carbon nanotubes (SWCNT), double-walled carbon nanotubes (DWNT), multi-walled carbon nanotubes (MWNT), and rope carbon nanotubes.

[0013] In addition, the porous fiber may include one or more selected from the group consisting of wool, cotton, linen, silk, rayon, acetate, nylon, polyester, acrylic, and polyurethane.

[0014] According to another aspect of the present invention, an energy harvester is provided comprising: a first electrode comprising a fiber bundle composite; a second electrode; and an electrolyte; wherein the fiber bundle composite comprises a fiber bundle comprising porous fibers and carbon nanotubes (CNTs) coated on said porous fibers.

[0015] In addition, the energy harvester may convert mechanical energy into electrical energy by compressing or stretching the fiber bundle composite in any one of the omnidirections, thereby receiving energy from all directions.

[0016] In addition, the second electrode may include one or more selected from the group consisting of gold, silver, copper, platinum, palladium, nickel, indium, aluminum, iron, rhodium, ruthenium, osmium, cobalt, molybdenum, zinc, vanadium, tungsten, titanium, manganese, chromium, and combinations thereof.

[0017] In addition, the second electrode may include a platinum mesh and a carbon nanotube bucky paper composite (pt mesh / CNT buckypaper).

[0018] In addition, the electrolyte may include one or more selected from the group consisting of hydrochloric acid, sulfuric acid, hydrofluoric acid, bromic acid, sodium chloride, potassium chloride, sodium hydroxide, organic electrolyte, lithium chloride, potassium hydroxide, and sodium sulfite.

[0019] In addition, the first electrode and the second electrode may each form an electrochemical double layer on the surface of the first electrode and the second electrode within the electrolyte.

[0020] In addition, the energy harvester may further include a compression-tension member that compresses or tensions the fiber bundle composite of the first electrode.

[0021] In addition, the energy harvester may further include an energy storage unit that stores electrical energy.

[0022] In addition, the above energy harvester may be one in which a redox reaction does not occur.

[0023] In addition, the first electrode and the second electrode may each be immersed in the electrolyte.

[0024] According to another aspect of the present invention, a method for manufacturing a fiber bundle composite is provided, comprising: (a) preparing a carbon nanotube dispersion by irradiating a solution containing carbon nanotube powder and a solvent with ultrasound; (b) coating a fiber bundle containing porous fibers by immersing it in the carbon nanotube dispersion; and (c) preparing a fiber bundle composite by drying the fiber bundle containing porous fibers coated with carbon nanotubes.

[0025] In addition, in step (a), the ultrasound may be performed for 0.2 to 3 hours, preferably 0.5 to 2 hours.

[0026] In addition, in step (a), the ultrasound may be performed at an intensity of 50 to 200 W, preferably 70 to 150 W.

[0027] In addition, in step (a), the carbon nanotube powder may comprise 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the solvent. Effects of the invention

[0028] The energy harvester comprising the fiber bundle composite of the present invention has excellent electrochemical properties and can be manufactured through a simple process. Furthermore, by compressing or stretching the fiber bundle composite in any one of the omnidirectional directions, the energy harvester can convert mechanical energy into electrical energy and receive energy from all directions, and has the effect of being usable in a liquid environment. Brief explanation of the drawing

[0029] These drawings are for reference to explain exemplary embodiments of the present invention, and therefore, the technical concept of the present invention should not be interpreted as being limited to the attached drawings. FIG. 1 is a schematic diagram showing a method for manufacturing a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention. FIG. 2 is a schematic diagram showing a method for manufacturing a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention. Figure 3 is an image showing a porous fiber energy harvester before and after coating with carbon nanotubes according to Example 1 of the present invention. FIG. 4 is a 3-electrode setup image for measuring the electrochemical performance of device Example 1, which includes Example 1 of the present invention. Figure 5 is an SEM image of a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention. FIG. 6a is a graph showing the change in electrochemical capacitance according to external pressure of a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention, and FIG. 6b is a graph showing the change in Short Circuit Current (SCC) of a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention. Figure 7 is a graph showing data analyzing the Peak Power of a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention. FIG. 8a is a setup image for evaluating the electrochemical characteristics of a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention, and FIG. 8b is an image showing the omnidirectionality of a porous fiber energy harvester coated with carbon nanotubes through a plot of the magnitude of Short Circuit Current (SCC) generation at each point of the porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention. Specific details for implementing the invention

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention.

[0031] However, the following description is not intended to limit the present invention to specific embodiments, and detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions could obscure the essence of the present invention.

[0032] The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to indicate the presence of the features, numbers, steps, actions, components, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, or combinations thereof.

[0033] Additionally, terms including ordinal numbers, such as "first," "second," etc., used below may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0034] Furthermore, when it is stated that a component is "formed" or "laminated" on another component, it should be understood that while it may be formed or laminated by being directly attached to the entire surface or one surface of the other component, there may also be other components present in between.

[0035] Hereinafter, the present invention will be described in detail regarding a fiber bundle composite, an omnidirectional chemomechanical energy harvester comprising the same, and a method for manufacturing the same. However, this is presented as an example and is not intended to limit the present invention, and the present invention is defined only by the scope of the claims set forth below.

[0036] According to one aspect of the present invention, a fiber bundle composite comprising: a fiber bundle comprising porous fibers; and carbon nanotubes (CNTs) coated on said porous fibers is provided.

[0037] In addition, the above fiber bundle composite may be intended for use in a chemo-mechanical energy harvester.

[0038] In addition, the above-mentioned chemomechanical energy harvester is a device that produces electrical energy based on changes in the electrochemical double layer within an electrolyte due to external pressure.

[0039] In addition, the fiber bundle may be in the shape of any one selected from the group consisting of a sphere, a cube, a rectangular prism, a cylinder, a polygonal prism, and combinations thereof, preferably a sphere.

[0040] In addition, the diameter of the fiber bundle may be 10 to 50 mm. Here, if the diameter of the fiber bundle is less than 10 mm, it is undesirable because it is too small and the amount of energy generated is insignificant, and if it exceeds 50 mm, it is undesirable because it is difficult to control the porous structure inside the fiber bundle.

[0041] In addition, the carbon nanotube (CNT) may include one or more types selected from the group consisting of single-walled carbon nanotubes (SWCNT), double-walled carbon nanotubes (DWNT), multi-walled carbon nanotubes (MWNT), and rope carbon nanotubes.

[0042] In addition, the porous fiber may include one or more selected from the group consisting of wool, cotton, linen, silk, rayon, acetate, nylon, polyester, acrylic, and polyurethane.

[0043] According to another aspect of the present invention, an energy harvester is provided comprising: a first electrode comprising a fiber bundle composite; a second electrode; and an electrolyte; wherein the fiber bundle composite comprises a fiber bundle comprising porous fibers and carbon nanotubes (CNTs) coated on said porous fibers.

[0044] In addition, the energy harvester may convert mechanical energy into electrical energy by compressing or stretching the fiber bundle composite in any one of the omnidirections, thereby receiving energy from all directions.

[0045] In addition, the second electrode may include one or more selected from the group consisting of gold, silver, copper, platinum, palladium, nickel, indium, aluminum, iron, rhodium, ruthenium, osmium, cobalt, molybdenum, zinc, vanadium, tungsten, titanium, manganese, chromium, and combinations thereof.

[0046] In addition, the second electrode may include a platinum mesh and a carbon nanotube bucky paper composite (pt mesh / CNT buckypaper).

[0047] In addition, the electrolyte may include one or more selected from the group consisting of hydrochloric acid, sulfuric acid, hydrofluoric acid, bromic acid, sodium chloride, potassium chloride, sodium hydroxide, organic electrolyte, lithium chloride, potassium hydroxide, and sodium sulfite.

[0048] In addition, the first electrode and the second electrode may each form an electrochemical double layer on the surface of the first electrode and the second electrode within the electrolyte.

[0049] In addition, the energy harvester may further include a compression-tension member that compresses or tensions the fiber bundle composite of the first electrode.

[0050] In addition, the energy harvester may further include an energy storage unit that stores electrical energy.

[0051] In addition, the above energy harvester may be one in which a redox reaction does not occur.

[0052] In addition, the first electrode and the second electrode may each be immersed in the electrolyte.

[0053] According to another aspect of the present invention, a method for manufacturing a fiber bundle composite is provided, comprising: (a) preparing a carbon nanotube dispersion by irradiating a solution containing carbon nanotube powder and a solvent with ultrasound; (b) coating a fiber bundle containing porous fibers by immersing it in the carbon nanotube dispersion; and (c) preparing a fiber bundle composite by drying the fiber bundle containing porous fibers coated with carbon nanotubes.

[0054] In addition, in step (a), the ultrasound may be performed for 0.2 to 3 hours, preferably 0.5 to 2 hours. Here, if the ultrasound irradiation time is less than 0.2 hours, the carbon nanotubes (CNT) are not sufficiently dispersed, which is undesirable, and if it exceeds 3 hours, the carbon nanotubes (CNT) are already completely dispersed, so additional ultrasound irradiation is not required, which is undesirable.

[0055] In addition, in step (a), the ultrasound may be performed at an intensity of 50 to 200 W, preferably 70 to 150 W. Here, if the ultrasound intensity is less than 50 W, it is undesirable because the ultrasound intensity is too weak for the carbon nanotubes (CNT) to be dispersed, and if it exceeds 200 W, it is undesirable because the dispersion solvent may evaporate in a high-temperature environment.

[0056] In addition, in step (a), the carbon nanotube powder may be included in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the solvent. Here, if the carbon nanotube powder is less than 0.1 parts by weight based on 100 parts by weight of the solvent, the density is too low for the carbon nanotubes (CNT) to penetrate into the interior of the porous fiber during coating, which is undesirable, and if it exceeds 5 parts by weight, the carbon nanotubes (CNT) are adsorbed onto the porous fiber in a bundle form, which is undesirable.

[0057] [Example]

[0058] The present invention will be explained in more detail below with reference to examples. However, this is for illustrative purposes only and does not limit the scope of the invention.

[0059] Example 1: Preparation of a Carbon Nanotube-Coated Porous Fiber Energy Harvester

[0060] FIG. 1 is a schematic diagram showing a method for manufacturing a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention, FIG. 2 is a schematic diagram showing a method for manufacturing a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention, and FIG. 3 is an image showing a porous fiber energy harvester before and after coating with carbon nanotubes according to Example 1 of the present invention.

[0061] Referring to FIGS. 1, 2, and 3, the surface area is 700 m² 2Single-walled carbon nanotube (SWCNT) powder with a content of 1 g or more was added at 1 wt% to a solvent solution of isopropyl alcohol (IPA, molar mass: 60.10 g / mol), and a dispersion was prepared by dispersing the single-walled carbon nanotube powder in the isopropyl alcohol solution by irradiating it with ultrasound for 1 hour at 70 to 90% of the power of a sonicator with an output of 130 W. A bundle containing porous wool fibers was immersed in the dispersion and dip-coated for 10 minutes. Subsequently, the bundle containing porous fibers dip-coated with single-walled carbon nanotubes was dried in an oven at a temperature of 70 ℃ for 1 hour. After drying, a bundle containing porous fibers dip-coated with single-walled carbon nanotubes was immersed again in the dispersion and dip-coated for 10 minutes, and dried in an oven at a temperature of 70°C for 1 hour so that the surface of the bundle was completely coated to prepare a fiber bundle composite.

[0062] Device Example 1: 3-Electrode Energy Harvester

[0063] FIG. 4 is a setup image of a three-electrode energy harvester for measuring the electrochemical performance of device Example 1, which includes Example 1 of the present invention. Referring to FIG. 4, a CNT / wool energy harvester is used as the working electrode (WE), a Pt mesh / CNT bucky paper is used as the counter electrode (CE), Ag / AgCl is used as the reference electrode (RE), and 0.1M HCl is used as the electrolyte. Here, any electrode with a capacitance greater than that of the working electrode (WE) can be used as the counter electrode (CE).

[0064] [Test Example]

[0065] Test Example 1: Scanning Electron Microscope (SEM) Image Analysis

[0066] Figure 5 is an SEM image of a porous fiber coated with carbon nanotubes according to Example 1 of the present invention. Referring to Figure 5, it was confirmed that the surface of the porous fiber was completely coated with carbon nanotubes.

[0067] Test Example 2: Short Circuit Current (SCC) Analysis

[0068] FIG. 6a is a graph showing the change in electrochemical capacitance according to external pressure of an energy harvester including a porous fiber coated with carbon nanotubes according to Example 1 of the present invention, and FIG. 6b is a graph showing the change in Short Circuit Current (SCC) of a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention. Referring to FIG. 6a and FIG. 6b, it was confirmed that the change in Short Circuit Current (SCC) of the porous fiber energy harvester coated with carbon nanotubes occurs repeatedly due to the change in electrochemical capacitance according to external pressure.

[0069] Test Example 3: Peak Power Analysis

[0070] Figure 7 is a graph showing data analyzing the peak power of an energy harvester containing a porous fiber coated with carbon nanotubes according to Example 1 of the present invention. Referring to Figure 7, it was confirmed that the peak power of the energy harvester containing the porous fiber coated with carbon nanotubes is 30 mW / kg and the matching impedance is 5 Ω.

[0071] Test Example 4: Analysis of Omnidirectional Electrochemical Characteristics of an Energy Harvester

[0072] FIG. 8a is a setup image for evaluating the electrochemical characteristics of a porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention, and FIG. 8b is an image showing the omnidirectionality of a porous fiber energy harvester coated with carbon nanotubes through a plot of the magnitude of Short Circuit Current (SCC) generation at each point of the porous fiber energy harvester coated with carbon nanotubes according to Example 1 of the present invention. Referring to FIG. 8a and FIG. 8b, the omnidirectionality of the porous fiber energy harvester coated with carbon nanotubes could be confirmed through a plot of the magnitude of Short Circuit Current (SCC) generation at each point of the porous fiber energy harvester coated with carbon nanotubes.

Claims

Claim 1 A fiber bundle composite comprising: a fiber bundle including porous fibers; and carbon nanotubes (CNTs) coated on said porous fibers, wherein said fiber bundles have a spherical shape and said porous fibers include wool, and is intended for use in a chemo-mechanical energy harvester. Claim 2 delete Claim 3 delete Claim 4 A fiber bundle composite according to claim 1, characterized in that the diameter of the fiber bundle is 10 to 50 mm. Claim 5 A fiber bundle composite according to claim 1, characterized in that the carbon nanotube (CNT) comprises one or more types selected from the group consisting of single-walled carbon nanotubes (SWCNT), double-walled carbon nanotubes (DWNT), multi-walled carbon nanotubes (MWNT), and rope carbon nanotubes. Claim 6 delete Claim 7 An energy harvester comprising: a first electrode including a fiber bundle complex; a second electrode; and an electrolyte; wherein the fiber bundle complex includes a fiber bundle including porous fibers and carbon nanotubes (CNTs) coated on said porous fibers, said fiber bundles having a spherical shape and said porous fibers including wool. Claim 8 An energy harvester according to claim 7, characterized in that the energy harvester can receive energy from all directions by converting mechanical energy into electrical energy through compression or tension of the fiber bundle composite in any one of the omnidirections. Claim 9 An energy harvester according to claim 7, characterized in that the second electrode comprises one or more selected from the group consisting of gold, silver, copper, platinum, palladium, nickel, indium, aluminum, iron, rhodium, ruthenium, osmium, cobalt, molybdenum, zinc, vanadium, tungsten, titanium, manganese, chromium, and combinations thereof. Claim 10 An energy harvester according to claim 7, characterized in that the second electrode comprises a platinum mesh and a carbon nanotube bucky paper composite (pt mesh / CNT buckypaper). Claim 11 An energy harvester according to claim 7, characterized in that the electrolyte comprises one or more selected from the group consisting of hydrochloric acid, sulfuric acid, hydrofluoric acid, bromic acid, sodium chloride, potassium chloride, sodium hydroxide, organic electrolyte, lithium chloride, potassium hydroxide, and sodium sulfite. Claim 12 An energy harvester according to claim 7, characterized in that the first electrode and the second electrode each form an electrochemical double layer on the surface of the first electrode and the second electrode within the electrolyte. Claim 13 An energy harvester according to claim 7, characterized in that the energy harvester further comprises a compression-tension member that compresses or tensions the fiber bundle composite of the first electrode. Claim 14 An energy harvester according to claim 7, characterized in that the energy harvester further includes an energy storage unit that stores electrical energy. Claim 15 In claim 7, the energy harvester is characterized by not undergoing a redox reaction. Claim 16 An energy harvester according to claim 7, characterized in that the first electrode and the second electrode are each immersed in the electrolyte. Claim 17 (a) a step of preparing a carbon nanotube dispersion by irradiating a solution containing carbon nanotube powder and a solvent with ultrasound; (b) a step of coating a fiber bundle containing porous fibers by immersing it in the carbon nanotube dispersion; and (c) a step of preparing a fiber bundle composite by drying the fiber bundle containing porous fibers coated with carbon nanotubes; wherein the fiber bundle has a spherical shape and the porous fibers contain wool, and the fiber bundle is intended for use in a chemo-mechanical energy harvester. Claim 18 A method for manufacturing a fiber bundle composite according to claim 17, characterized in that, in step (a), the ultrasound is performed for 0.2 to 3 hours. Claim 19 A method for manufacturing a fiber bundle composite according to claim 17, characterized in that, in step (a), the ultrasound is performed at an intensity of 50 to 200 W. Claim 20 A method for manufacturing a fiber bundle composite according to claim 17, characterized in that, in step (a), the carbon nanotube powder comprises 0.1 to 5 parts by weight based on 100 parts by weight of the solvent.

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