KR102661745B1 - Carbon nanotube yarn composite inclluding metal nanorod, energy harvester comprising same and method of fabricatin same - Google Patents

Abstract

The present invention relates to a carbon nanotube yarn having a plurality of carbon nanotubes, wherein the plurality of carbon nanotubes are aligned in the longitudinal direction; and a metal nanorod positioned between the carbon nanotube and the neighboring carbon nanotube, wherein the carbon nanotube yarn is coiled. . The carbon nanotube yarn composite including the carbon nanotube yarn composite of the present invention, the energy harvester including the same, and the manufacturing method thereof include metal nanoparticle rods, thereby improving the conductivity of the carbon nanotube yarn composite.

Description

Carbon nanotube yarn composite containing metal nanorods, energy harvester containing the same, and manufacturing method thereof {CARBON NANOTUBE YARN COMPOSITE INCLLUDING METAL NANOROD, ENERGY HARVESTER COMPRISING SAME AND METHOD OF FABRICATIN SAME}

The present invention relates to a carbon nanotube yarn composite containing metal nanorods, an energy harvester containing the same, and a method for manufacturing the same. More specifically, it relates to a carbon nanotube yarn complex containing metal nanorods with improved conductivity by including metal nanorods. It relates to a tube yarn composite, an energy harvester including the same, and a method of manufacturing the same.

Recently, as problems such as depletion of fossil energy, environmental pollution, and increasing energy demand have emerged, the development of alternative energy that deviates from the existing energy generation system is required.

Accordingly, interest in energy harvesting, which converts wasted energy around us into useful electrical energy, is increasing as an alternative energy development technology. Among them, kinetic energy is generated through the principle of inducing static electricity through contact. Research on devices that convert energy into electrical energy is being conducted from various angles.

Since the discovery of the electromagnetic induction phenomenon, efforts have been made to apply it to technology for producing electricity using static electricity generated by friction. As a result, in 2012, a research team at the Georgia Institute of Technology developed the first friction generator. However, the friction generator had a problem in that it was difficult to commercialize it in practice due to its low output current and transmission power.

Accordingly, a technology has recently been announced that improves the short-circuit current density and power efficiency of triboelectric generators by introducing three-dimensional micro-nano patterning, nanowire structure formation, and nanoparticle formation on the friction surface of triboelectric generators.

However, this technology had a problem in that it required other types of energy, such as mechanical deformation, to obtain electrical energy.

Republic of Korea Patent Publication No. 10-2018-0013549 Republic of Korea Patent Publication No. 10-2020-0024255

The purpose of the present invention is to provide a carbon nanotube yarn composite with improved conductivity by including metal nanorods, an energy harvester including the same, and a method for manufacturing the same.

The purpose of the present invention is to produce carbon containing longitudinally aligned yarns and metal nanorods by using LAY-spinning, which applies twist after arranging carbon nanotube yarns in the longitudinal direction (Longitudinally-Aligned yarn, LAY). The object is to provide a carbon nanotube yarn composite capable of producing a nanotube yarn composite, an energy harvester including the same, and a method for manufacturing the same.

In addition, the present invention can be used in various industries that require electrical energy in emergency situations or extreme environments, and unlike piezo and triboelectric, which are vulnerable to moisture, it generates electrical energy from electrolytes such as seawater, sweat, and body fluids, making it suitable for use in smart electronics and wearables. The object is to provide a carbon nanotube yarn composite that can be used as an energy source for devices, an energy harvester containing the same, and a method for manufacturing the same.

According to one aspect of the present invention, a carbon nanotube yarn having a plurality of carbon nanotubes, wherein the plurality of carbon nanotubes are aligned in the longitudinal direction; and a metal nanorod located between the carbon nanotube and the neighboring carbon nanotube, wherein the carbon nanotube yarn is coiled. A carbon nanotube yarn composite is provided. .

Additionally, the metal nanorod may have a diameter of 1 to 120 nm.

In addition, the ratio of the content of the metal nanorod (p) to the total content of the carbon nanotube yarn (y) and the metal nanorod (p) (y+p) (p/(y+p), weight %) It may be 20 to 99% by weight.

Additionally, the metal nanorod may include one or more types selected from the group consisting of Ag, Au, and Pt.

Additionally, the carbon nanotube yarn composite may be uniformly twisted along the length direction.

Additionally, the bias angle of the carbon nanotube yarn composite expressed by Equation 1 below may be uniformly distributed along the length direction.

[Equation 1]

Bias angle (˚) = The angle formed between the longitudinal direction of the yarn and the twisting direction.

Additionally, the bias angle may be 20 to 56 degrees.

Additionally, the carbon nanotube yarn composite may have a spring index of 0.3 to 2.0, represented by Equation 2 below.

[Equation 2]

Spring index = {outer diameter of coil + inner diameter of coil)/2}/diameter of yarn
In Equation 2, the coil is a twisted carbon nanotube yarn composite, the outer diameter of the coil (μm) is the outer diameter of the twisted carbon nanotube yarn composite, and the inner diameter of the coil (μm) is the diameter of the inner hollow of the twisted carbon nanotube yarn composite. , and the diameter of the yarn (μm) is the diameter of the twisted carbon nanotube yarn composite.

According to another aspect of the present invention, a first electrode 100 including a carbon nanotube yarn composite; second electrode 200; and an electrolyte 300; wherein the carbon nanotube yarn composite (coiled carbon nanotube yarn composite) has a plurality of carbon nanotubes, and the plurality of carbon nanotubes are aligned in the longitudinal direction. (carbon nanotube yarn); and a metal nanorod positioned between the carbon nanotube and the neighboring carbon nanotube, wherein the carbon nanotube yarn is coiled.

In addition, the first electrode 100 and the second electrode 100 each form an electrochemical double layer on the surfaces of the first electrode 100 and the second electrode 100 within the electrolyte 300. can be formed.

In addition, the energy harvester 10 may further include a tensioning portion 400 that tensions the carbon nanotube yarn composite of the first electrode 100 in the longitudinal direction.

Additionally, the energy harvester may generate electrical energy as the carbon nanotube yarn composite 10 is stretched or contracted in the longitudinal direction.

Additionally, the first electrode and the second electrode may not be oxidized or reduced when electrical energy is generated.

According to another aspect of the present invention, (a) a carbon nanotube sheet containing metal nanorods is coated by contacting a metal nanorod solution containing metal nanorods on a carbon nanotube sheet containing carbon nanotubes. Preparing a carbon nanotube sheet composite; (b) preparing a washed carbon nanotube sheet composite by washing the carbon nanotube sheet composite with a polar solvent; (c) lifting one end of the washed carbon nanotube sheet composite to manufacture a carbon nanotube sheet composite in which the carbon nanotubes and the metal nanorods are aligned in the longitudinal direction of the carbon nanotubes, respectively; (d) applying twist to the longitudinally aligned carbon nanotube sheet composite to produce a longitudinally aligned carbon nanotube yarn composite; and (e) manufacturing a twisted carbon nanotube yarn composite by further twisting the longitudinally aligned carbon nanotube sheet composite.

In addition, the method for producing the carbon nanotube yarn composite is between steps (d) and (e), (d') additionally applying twist to the carbon nanotube yarn composite aligned in the longitudinal direction to form a uniform uniformity along the longitudinal direction. It may further include manufacturing a carbon nanotube yarn composite that is twisted and has a bias angle of 20 to 56 degrees.

Additionally, in step (b), the washed carbon nanotube sheet composite may be a composite in which metal nanorods that are not aligned in the longitudinal direction of the carbon nanotubes have been removed.

Additionally, the carbon nanotube sheet of step (a) may include multi-walled carbon nanotubes.

Additionally, the bias angle of the carbon nanotube yarn composite expressed by Equation 1 below may be uniformly distributed along the length direction.

[Equation 1]

Bias angle (˚) = The angle formed between the longitudinal direction of the yarn and the twisting direction.

The bias angle may be 20 to 56 degrees.

Additionally, the carbon nanotube yarn composite aligned in the longitudinal direction of step (d) may be in the form of a bundle including a plurality of carbon nanotubes aligned in the longitudinal direction.

According to another aspect of the present invention, (1) manufacturing a carbon nanotube sheet cylinder by rolling a carbon nanotube sheet containing carbon nanotubes; (2) twisting the carbon nanotube sheet cylinder to produce non-homogeneously twisted carbon nanotube yarn along the length direction; (3) manufacturing a longitudinally aligned carbon nanotube yarn (LAY) by untwisting the carbon nanotube yarn that is unevenly twisted along the longitudinal direction; (4) A carbon nanotube yarn aligned in the longitudinal direction, including a carbon nanotube yarn coated with metal nanorods by contacting the carbon nanotube yarn aligned in the longitudinal direction with a metal nanorod solution containing metal nanorods. Preparing a composite (longitudinally aligned carbon nanotube yarn composite, LAYC); (5) twisting the carbon nanotube yarn composite aligned in the longitudinal direction to produce a homogeneously twisted carbon nanotube yarn composite along the longitudinal direction; and (6) manufacturing a coiled carbon nanotube yarn composite by further twisting the yarn composite uniformly twisted along the longitudinal direction. A method for producing a carbon nanotube yarn composite comprising a is provided. do.

The carbon nanotube yarn composite containing metal nanorods of the present invention, the energy harvester containing the same, and the manufacturing method thereof include metal nanorods, thereby improving the conductivity of the carbon nanotube yarn complex.

In addition, the present invention improves conductivity, suggesting the possibility of continuous production, and exhibits excellent performance, which may be advantageous for industrialization.

In addition, the present invention uses LAY-spinning, which applies twist after arranging carbon nanotube yarns in the longitudinal direction (Longitudinally-Aligned yarn, LAY), to produce carbon nanotubes containing longitudinally aligned yarns and metal nanorods. Tube yarn composites can be prepared.

In addition, the present invention can be used in various industries that require electrical energy in emergency situations or extreme environments, and unlike piezo and triboelectric, which are vulnerable to moisture, it generates electrical energy from electrolytes such as seawater, sweat, and body fluids, making it suitable for use in smart electronics and wearables. It can be used as an energy source for devices, etc.

1A and 1B are schematic diagrams showing the structures of a three-electrode energy harvester and a two-electrode energy harvester according to the present invention.
Figure 2 is a process schematic diagram showing a method of manufacturing a carbon nanotube yarn composite according to an embodiment of the present invention.
Figure 3 is a process schematic diagram illustrating steps C to E of Figure 2 in three cases.
Figure 4 is a process schematic diagram showing a method of manufacturing a carbon nanotube yarn composite according to another embodiment of the present invention.
Figures 5a and 5b are graphs showing the amount of change in CV of the energy harvester according to Device Example 1 and Device Comparative Example 1-1.
Figure 6 is a graph showing the amount of change in OCV of the energy harvester according to Device Example 1 and Device Comparative Example 1-1.
Figure 7 is a graph showing the power of the energy harvester according to Device Example 2 and Device Comparative Example 2-1.
Figure 8a is a schematic diagram of the generated power of the carbon nanotube yarn composite (CNT/AgNR) according to the present invention, and Figure 8b is a schematic diagram of the improved electron transfer structure of the carbon nanotube yarn composite (CNT/AgNR) according to the present invention.
Figure 9 is a graph showing capacitance according to tension of energy harvesters using different manufacturing methods.
Figure 10 is a graph showing the peak voltage and gravimetric power of energy harvesters using different manufacturing methods.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Additionally, terms including ordinal numbers, such as first, second, etc., which will be used below, may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component without departing from the scope of the present invention, and similarly, the second component may also be named a first component.

Additionally, when a component is referred to as being “on another component,” “formed on another component,” “located on another component,” or “stacked on another component,” It may be formed by being directly attached to the front or one side of the surface of another component, positioned, or stacked, but it should be understood that other components may further exist in the middle.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

1A and 1B are schematic diagrams showing the structures of a three-electrode energy harvester and a two-electrode energy harvester according to the present invention. Hereinafter, a carbon nanotube yarn composite containing metal nanorods of the present invention and an energy harvester containing the same will be described with reference to FIGS. 1A and 1B.

The present invention relates to a carbon nanotube yarn having a plurality of carbon nanotubes, wherein the plurality of carbon nanotubes are aligned in the longitudinal direction; and a metal nanorod positioned between the carbon nanotube and the neighboring carbon nanotube, wherein the carbon nanotube yarn is coiled. .

The metal nanorod may have a diameter of 1 to 120 nm, preferably 30 to 90 nm, and more preferably 50 to 70 nm. If the diameter of the metal nanorod is less than 1 nm, it is not desirable because it is not sufficient to bridge the gap between carbon nanotubes and does not improve conductivity, and if it is more than 120 nm, it is undesirable because it reduces the mechanical properties of the twisted carbon nanotube yarn. don't do it Also, more preferably, the diameter of the metal nanorod is 50 to 70 nm, which is similar to or smaller than the spacing between carbon nanotubes constituting the twisted carbon nanotube yarn.

The carbon nanotube yarn composite may include metal nanorods in which the longitudinal direction of the metal nanorods is aligned with the longitudinal direction of the carbon nanotubes.

The ratio of the content of the metal nanorod (p) to the total content of the carbon nanotube yarn (y) and the metal nanorod (p) (y+p) (p/(y+p), weight %) is It may be 20 to 99% by weight, preferably 15 to 30% by weight. If the content ratio (p/(y+p), weight %) of the metal nanorod (p) is less than 20% by weight, the metal nanorod is used to improve conductivity between carbon nanotubes constituting the twisted carbon nanotube yarn. The amount is not sufficient and is undesirable, and if it exceeds 99% by weight, the mechanical properties of the twisted carbon nanotube yarn are deteriorated, which is undesirable.

The metal nanorod may include one or more types selected from the group consisting of Ag, Au, and Pt.

The carbon nanotube yarn composite may be uniformly twisted along the length direction.

The bias angle of the carbon nanotube yarn composite expressed by Equation 1 below may be uniformly distributed along the length direction.

[Equation 1]

Bias angle (˚) = The angle formed between the longitudinal direction of the yarn and the twisting direction.

The bias angle may be 20 to 56 degrees.

The bias angle of the carbon nanotube yarn, in which the plurality of carbon nanotubes are aligned in the longitudinal direction, may be less than 10°.

The carbon nanotube yarn composite may have a spring index of 0.3 to 2.0, represented by Equation 2 below.

[Equation 2]

Spring index = {outer diameter of coil + inner diameter of coil)/2}/diameter of yarn
In Equation 2, the coil is a twisted carbon nanotube yarn composite, the outer diameter of the coil (μm) is the outer diameter of the twisted carbon nanotube yarn composite, and the inner diameter of the coil (μm) is the diameter of the inner hollow of the twisted carbon nanotube yarn composite. , and the diameter of the yarn (μm) is the diameter of the twisted carbon nanotube yarn composite.

In addition, the present invention includes a first electrode 100 including a carbon nanotube yarn composite; second electrode 200; and an electrolyte 300; wherein the carbon nanotube yarn composite (coiled carbon nanotube yarn composite) has a plurality of carbon nanotubes, and the plurality of carbon nanotubes are aligned in the longitudinal direction. (carbon nanotube yarn); and a metal nanorod positioned between the carbon nanotube and the neighboring carbon nanotube, wherein the carbon nanotube yarn is coiled.

The first electrode 100 and the second electrode 100 form an electrochemical double layer on the surfaces of the first electrode 100 and the second electrode 100, respectively, within the electrolyte 300. can do.

The energy harvester 10 may further include a tensioning portion 400 that tensions the carbon nanotube yarn composite of the first electrode 100 in the longitudinal direction.

The energy harvester may generate electrical energy as the carbon nanotube yarn composite 10 is stretched or contracted in the longitudinal direction.

The first electrode and the second electrode may not be oxidized or reduced when electrical energy is generated.

The energy harvester may further include an energy storage unit (not shown) that stores electrical energy.

A redox reaction may not occur in the energy harvester.

The electrolyte may be a liquid electrolyte or a solid electrolyte.

The electrolyte is a liquid electrolyte, and the first electrode 100 and the second electrode 200 may each be immersed in the liquid electrolyte.

The electrolyte may include one or more selected from the group consisting of HCl, H ₂ SO ₄ , HF, HBr, NaCl, KCl, NaOH, and organic electrolytes.

FIG. 2 is a process schematic diagram showing a method of manufacturing a twisted carbon nanotube yarn composite according to an embodiment of the present invention, and FIG. 3 is a process schematic diagram illustrating steps C to E of FIG. 2 in three cases. Additionally, Figure 4 is a process schematic diagram showing a method of manufacturing a twisted carbon nanotube yarn composite according to another embodiment of the present invention. Hereinafter, the manufacturing method of the carbon nanotube yarn composite will be described with reference to FIGS. 2 to 4. In Figures 2 to 4, the blue arrow indicates a process of applying clockwise rotation to the yarn when viewed from above, and the red arrow indicates a process of applying counterclockwise rotation.

In addition, the present invention provides (a) a carbon nanotube sheet composite comprising a carbon nanotube sheet coated with metal nanorods by contacting a metal nanorod solution containing metal nanorods on a carbon nanotube sheet containing carbon nanotubes; manufacturing a; (b) preparing a washed carbon nanotube sheet composite by washing the carbon nanotube sheet composite with a polar solvent; (c) lifting one end of the washed carbon nanotube sheet composite to manufacture a carbon nanotube sheet composite in which the carbon nanotubes and the metal nanorods are aligned in the longitudinal direction of the carbon nanotubes, respectively; (d) applying twist to the longitudinally aligned carbon nanotube sheet composite to produce a longitudinally aligned carbon nanotube yarn composite; and (e) manufacturing a twisted carbon nanotube yarn composite by further twisting the longitudinally aligned carbon nanotube sheet composite.

The method for producing the carbon nanotube yarn composite is between steps (d) and (e), (d') additionally applying twist to the carbon nanotube yarn composite aligned in the longitudinal direction to uniformly along the longitudinal direction. It may further include manufacturing a carbon nanotube yarn composite that is twisted and has a bias angle of 20 to 56 degrees.

In step (b), the washed carbon nanotube sheet composite has metal nanorods in which the longitudinal direction of the metal nanorod is not aligned with the longitudinal direction of the carbon nanotubes are removed, and the longitudinal direction of the metal nanorod is not aligned with the longitudinal direction of the carbon nanotube. It may include metal nanorods aligned in the longitudinal direction of the carbon nanotubes.

The carbon nanotube sheet of step (a) may include multi-walled carbon nanotubes.

The bias angle of the carbon nanotube yarn composite in step (f), expressed by Equation 1 below, may be uniformly distributed along the length direction.

[Equation 1]

Bias angle (˚) = The angle formed between the longitudinal direction of the yarn and the twisting direction.

The bias angle may be 20 to 56 degrees.

The bias angle of the lower part may be the same as the bias angle of the upper part.

The carbon nanotube yarn composite aligned in the longitudinal direction of step (d) may have a bias angle of less than 10° and may be a carbon nanotube yarn composite including carbon nanotubes aligned in the longitudinal direction.

The longitudinally aligned carbon nanotube yarn composite of step (d) may be in the form of a bundle including a plurality of longitudinally aligned carbon nanotubes.

The longitudinally aligned carbon nanotube yarn composite of step (d) remains uniformly twisted by the load along the longitudinal direction, and the longitudinally aligned carbon nanotube yarn composite of step (d) is step It may be less twisted than the carbon nanotube yarn composite uniformly twisted along the longitudinal direction in (e).

The polar solvent may include ethanol.

Step (e) applies a load to the lower end of the carbon nanotube yarn composite aligned in the longitudinal direction and fixes it so that it does not rotate, and then rotates the upper end to create a carbon nanotube yarn that has a uniform bias angle and is uniformly twisted along the longitudinal direction. This may be a step of manufacturing a composite.

The method of manufacturing a carbon nanotube yarn composite according to steps (a) to (f) includes using carbon nanotubes as a host and metal nanorods as guests, and dropping a metal nanorod solution onto a carbon nanotube sheet or using carbon nanotubes as a guest. This may be a method of manufacturing a biscrolled yarn composite in which a carbon nanotube sheet composite is manufactured by directly wetting the sheet and then lifting one end of the carbon nanotube sheet composite with tweezers. Carbon nanotube yarn composites manufactured using the biscrolling method allow metal nanorods to be uniformly distributed inside the CNT yarn.

The manufacturing method of the carbon nanotube yarn composite according to steps (a) to (f) is a manufacturing method using biscrolling of FIG. 4, and metal nanorods are placed on a carbon nanotube sheet arranged in one direction as shown in A. After pouring the solution, wash it with ethanol as in B. The washing process with ethanol is performed to wash away impurities other than metal nanorods that have entered between the carbon nanotube sheets and to remove metal nanorods that are not aligned in the same direction as the longitudinal direction of the carbon nanotubes. At this time, the proportion of metal nanorods in C is 15 to 30 wt%. A twisted carbon nanotube yarn composite can be manufactured using a carbon nanotube sheet composite including a carbon nanotube sheet coated with metal nanorods prepared in C.

In addition, the present invention includes the steps of (1) rolling a carbon nanotube sheet containing carbon nanotubes to manufacture a carbon nanotube sheet cylinder; (2) twisting the carbon nanotube sheet cylinder to produce non-homogeneously twisted carbon nanotube yarn along the length direction; (3) manufacturing a longitudinally aligned carbon nanotube yarn (LAY) by untwisting the carbon nanotube yarn that is unevenly twisted along the longitudinal direction; (4) A carbon nanotube yarn aligned in the longitudinal direction, including a carbon nanotube yarn coated with metal nanorods by contacting the carbon nanotube yarn aligned in the longitudinal direction with a metal nanorod solution containing metal nanorods. Preparing a composite (longitudinally aligned carbon nanotube yarn composite, LAYC); (5) twisting the carbon nanotube yarn composite aligned in the longitudinal direction to produce a homogeneously twisted carbon nanotube yarn composite along the longitudinal direction; and (6) manufacturing a coiled carbon nanotube yarn composite by further twisting the uniformly twisted yarn composite along the longitudinal direction. do.

Step (2) applies a first load to the bottom of the carbon nanotube sheet cylinder, and twists while applying rotation to the top to produce a non-homogeneously twisted carbon nanotube yarn along the longitudinal direction. It may be a step of manufacturing.

In step (2), the first load may be any one selected from the group consisting of conditions 1 to 4 below.

[Condition 1] 40 MPa < W

[Condition 2] 1 MPa ≤ W ≤40 MPa

[Condition 3] 0 MPa < W < 1 MPa

[Condition 4] W = 0 MPa

In conditions 1 to 4 above, W is the first load.

In step (2), when the first load is a load according to [Condition 1], the carbon nanotube sheet of the carbon nanotube sheet cylinder may be broken, and the first load is according to [Condition 3] In the case of a load, the carbon nanotube sheet cylinder may be rolled up due to rotation (torsion). Therefore, when the first load is a load according to [Condition 2], it may be a desirable load for manufacturing a carbon nanotube yarn that is unevenly twisted along the longitudinal direction.

Step (3) is a step of applying a second load to the bottom of the carbon nanotube yarn that is unevenly twisted along the longitudinal direction and naturally unwinding it to produce a longitudinally aligned carbon nanotube yarn (LAY). ; may be.

In step (3), the second load may be equal to the first load.

In step (3), when the second load is a load according to [Condition 1] that is heavier than the first load, the carbon nanotube yarn unevenly twisted along the longitudinal direction may be broken, and the second load If the load according to [Condition 3] is heavier than the first load, uneven twist of the carbon nanotube yarn unevenly twisted along the longitudinal direction may remain. Additionally, when the second load is a load according to [Condition 4], that is, when the load is removed, the carbon nanotube yarn that is unevenly twisted along the longitudinal direction may be rolled up. Therefore, when the second load is a load according to [Condition 2], the same as the first load, it may be a desirable load for manufacturing carbon nanotube yarns aligned in the longitudinal direction and having a bias angle of less than 10°. At this time, in conditions 1 to 4, W is the second load.

The carbon nanotube yarn aligned in the longitudinal direction of step (3) may be in the form of a bundle each including a plurality of carbon nanotubes aligned in the longitudinal direction.

The carbon nanotube yarn aligned in the longitudinal direction of step (3) may have a bias angle of less than 10° and may be a carbon nanotube yarn including carbon nanotubes aligned in the longitudinal direction.

In step (4), the metal nanorod solution is brought into contact with the carbon nanotube yarn aligned in the longitudinal direction by dropping the metal nanorod solution on the carbon nanotube yarn aligned in the longitudinal direction. Carbon nanotube yarns aligned in the longitudinal direction may be immersed in the metal nanorod solution and brought into contact.

The carbon nanotube yarn composite aligned in the longitudinal direction of step (4) may be in the form of a bundle each including a plurality of carbon nanotubes aligned in the longitudinal direction.

The carbon nanotube yarn composite aligned in the longitudinal direction of step (4) may have a bias angle of less than 10° and may be a carbon nanotube yarn composite including carbon nanotubes aligned in the longitudinal direction.

Step (5) applies a third load to the bottom of the carbon nanotube yarn composite aligned in the longitudinal direction and twists it to form a homogeneously twisted carbon nanotube yarn composite along the longitudinal direction. It may be a manufacturing step.

In step (5), the third load may be equal to or smaller than the first load.

Step (4) is (4') contacting the carbon nanotube yarn aligned in the longitudinal direction with a metal nanorod solution containing metal nanorods to form a carbon nanotube yarn coated with metal nanorods in the longitudinal direction. Preparing a longitudinally aligned carbon nanotube yarn composite (LAYC); and (4'') washing the longitudinally aligned carbon nanotube yarn composite with a polar solvent to prepare a longitudinally aligned carbon nanotube yarn composite.

In step (4''), the washed longitudinally aligned carbon nanotube yarn composite has metal nanorods in which the longitudinal direction of the metal nanorod is not aligned in the longitudinal direction of the carbon nanotubes removed, and the metal nanorod is The longitudinal direction of the nanorod may include metal nanorods aligned with the longitudinal direction of the carbon nanotubes.

The manufacturing method of the carbon nanotube yarn composite according to steps (1) to (6) can be explained with Figures 2 and 3. Specifically, steps C, D, and E of FIG. 2 can be performed in three ways: 1, 2, and 3 of FIG. 3. In addition, in the marking of both ends of the yarn in Figure 3, orange indicates a fixed part, and blue indicates a state in which the twist can be unraveled.

Method 1 in Figure 3 is to fix the top of the carbon nanotube yarn (LAY) aligned in the longitudinal direction and drop the metal nanorod solution below in a state where the twist can be released, and method 2 is to drop the metal nanorod solution in a state where the carbon nanotube yarn (LAY) is aligned in the longitudinal direction. The metal nanorod solution is dropped by fixing both the top and bottom of the carbon nanotube yarn (LAY) so that the twist cannot be unraveled. Method 2 suggests that a composite can be manufactured continuously by passing a metal nanorod solution through a carbon nanotube yarn. In addition, method 3 produces carbon nanotube yarns uniformly twisted along the longitudinal direction by twisting carbon nanotube yarns (LAY) aligned in the longitudinal direction so that the bias angle is 25° or less, and carbon nanotube yarns uniformly twisted along the longitudinal direction. By fixing both the top and bottom of the nanotube yarn, the metal nanorod solution is dropped in a state where the twist cannot be undone.

[Example]

Hereinafter, the present invention will be described in more detail through examples. However, this is for illustrative purposes only and does not limit the scope of the present invention.

Example 1: 60nm Ag nanorod/ coiled CNT composite

The manufacturing method will be described below with reference to FIGS. 2 and 3. First, a multi-walled carbon nanotube sheet (MWCNT-sheet, sheet density: 2.1 μg/cm ² ) with a width of 4 cm and a length of 30 cm was extracted from the spinnable MWCNT-forest and prepared by overlapping two layers. The MWCNT-sheet was shaped into a cylinder, and a weight of 7.5 MPa was applied to the bottom to prevent rotation. Afterwards, while rotating the top clockwise, passing through stage A, a non-homogeneously twisted carbon nanotube yarn of the same shape as stage B was manufactured. The non-homogeneously twisted carbon nanotube yarn has a similar amount of twist at the top and bottom, but has less twist in the middle, and the twist density on the surface is not uniform in the longitudinal direction. am.

Next, the twist applied while rotating clockwise was rotated counterclockwise to release the twist, thereby producing a longitudinally aligned carbon nanotube yarn (LAY) in the same shape as step C. The carbon nanotube yarn (LAY) aligned in the longitudinal direction has only the twist maintained by the weight at the bottom, and is a yarn in which carbon nanotubes bundled in the longitudinal direction are arranged.

Next, referring to step C of FIG. 2 and method 1 of FIG. 3 below, a metal nanorod solution is applied to the longitudinally aligned carbon nanotube yarn (LAY) prepared so that the upper end is fixed and the lower end can be untwisted. By dropping, a longitudinally aligned carbon nanotube yarn composite (LAYC) containing carbon nanotubes coated with metal nanoparticles was manufactured. At this time, the metal nanorod solution was prepared by mixing silver nanorod (Sigma Aldrich) with a diameter of 60 nm and ethanol in a 5:5 ratio.

Next, the weight was changed to a load of 1.07 MPa, which is lighter than 7.5 MPa, at the bottom of the longitudinally aligned carbon nanotube yarn composite (LAYC), and twist was applied while rotating the top clockwise to produce uniformly twisted carbon nanotubes. A tube yarn composite (homogeneously twisted carbon nanotube yarn composite) was prepared. The uniformly twisted carbon nanotube yarn composite is a yarn with a uniform surface twist density in the longitudinal direction.

Next, the top of the uniformly twisted carbon nanotube yarn composite was rotated clockwise and twist was applied until a coil was formed to form a coiled carbon nanotube yarn composite with a spring index of 0.68. nanotube yarn composite) was manufactured.

Example 2: Manufacturing Ag nanorod/coiled CNT composite using biscrolling

The manufacturing method will be described below with reference to Figure 4. First, a multi-walled carbon nanotube sheet (MWCNT-sheet, sheet density: 2.1 μg/cm ² ) with a width of 4 cm and a length of 30 cm was extracted from the spinnable MWCNT-forest and prepared by overlapping two layers. A metal nanorod solution was poured and applied on the MWCNT-sheet to prepare a carbon nanotube sheet composite including a carbon nanotube sheet coated with metal nanorods. At this time, the metal nanorod solution was prepared by mixing silver nanorod (Sigma Aldrich) with a diameter of 60 nm and ethanol in a 5:5 ratio. Next, the carbon nanotube sheet composite was washed with ethanol to remove silver nanorods that were not aligned in the longitudinal direction of the carbon nanotubes on the surface.

Afterwards, one end of the cleaned carbon nanotube sheet composite was lifted with tweezers and a weight of 1.07 MPa was applied and fixed so as not to rotate. At this time, a longitudinally aligned carbon nanotube yarn composite having a uniform bias angle of less than 10° is manufactured by the load.

Next, twist was applied clockwise to produce a carbon nanotube yarn composite with a uniform bias angle as E and uniformly twisted along the length direction. Subsequently, continuous twisting was applied to prepare a twisted carbon nanotube yarn composite such as F.

Comparative Example 1: Pristine coiled CNT (LAY-spinning)

In Example 1, instead of dropping the metal nanorod solution on the longitudinally aligned carbon nanotube yarn (LAY), the metal nanorod solution was not dropped on the longitudinally aligned carbon nanotube yarn (LAY). A coiled carbon nanotube yarn with a spring index of 0.73 was manufactured in the same manner as in Example 1, except that.

Comparative Example 2: Preparation of twisted carbon nanotube yarn containing non-homogeneously twisted yarn (Cone-spinning)

First, a multi-walled carbon nanotube sheet (MWCNT-sheet, sheet density: 2.1 μg/cm ² ) with a width of 4 cm and a length of 30 cm was extracted from the spinnable MWCNT-forest and prepared by overlapping two layers. The MWCNT-sheet was shaped into a cylinder, and a certain weight was applied to the bottom to prevent it from rotating. Afterwards, the top was rotated clockwise to produce a non-homogeneously twisted yarn of the same shape as stage B after passing stage A of FIG. 3. A coiled carbon nanotube yarn was manufactured by rotating the top of the non-homogeneously twisted yarn clockwise and applying twist until a coil was formed.

Table 1 below summarizes the spring index of the twisted carbon nanotube yarn composite according to Example 1 and Comparative Example 1 and the resistance per length of the twisted carbon nanotube yarn composite measured using a multimeter.

Comparative Example 1
(Pristine coiled CNT) Example 1
(60nm Ag nanorod/coiled CNT) spring index 0.73 0.68 Resistance 200 Ω/cm 62Ω/cm

[3-electrode energy harvester]

Device Example 1: Including 60nm Ag nanorod/coiled CNT composite

The twisted carbon nanotube yarn composite (2 cm) according to Example 1 was used as a working electrode (WE), Pt-mesh was used as a counter electrode (CE), and Ag/Ag was used as a reference electrode (RE). AgCl was used.

Referring to Figure 1a, an energy harvester was manufactured by immersing the working electrode, counter electrode, and feel electrode in 0.1M HCl electrolyte.

Device Comparison Example 1-1: Including Pristine coiled CNT

The same method as Device Example 1 except that instead of using the twisted carbon nanotube yarn composite according to Example 1 as the working electrode in Device Example 1, the twisted carbon nanotube yarn according to Comparative Example 1 was used as the working electrode. An energy harvester was manufactured using this method.

Device Comparative Example 1-2: Twisted carbon nanotube yarn including non-uniformly twisted yarn

The same method as Device Example 1 except that instead of using the twisted carbon nanotube yarn composite according to Example 1 as the working electrode in Device Example 1, the twisted carbon nanotube yarn according to Comparative Example 2 was used as the working electrode. An energy harvester was manufactured using this method.

[2-electrode energy harvester]

Device Example 2: Including 20nm Ag particle/coiled CNT composite

The twisted carbon nanotube composite (2 cm) according to Example 1 was used as a working electrode (WE), and Pt-mesh was used as a counter electrode (CE).

Referring to Figure 1b, a self-charging energy harvester was manufactured by immersing the counter electrode and the working electrode in 0.1M HCl electrolyte.

Device Comparison Example 2-1: Including Pristine coiled CNT

The same method as Device Example 2 except that instead of using the twisted carbon nanotube yarn composite according to Example 1 as the working electrode in Device Example 2, the twisted carbon nanotube yarn according to Comparative Example 1 was used as the working electrode. An energy harvester was manufactured using this method.

Device Comparative Example 2-2: Twisted carbon nanotube yarn including non-uniformly twisted yarn

The same method as Device Example 2 except that instead of using the twisted carbon nanotube yarn composite according to Example 1 as the working electrode in Device Example 2, the twisted carbon nanotube yarn according to Comparative Example 2 was used as the working electrode. An energy harvester was manufactured using this method.

[Test example]

Test Example 1: Check CV change amount

Figures 5a and 5b are graphs showing the amount of change in CV of the energy harvester according to Device Example 1 and Device Comparative Example 1-1.

Cyclic voltammetry was measured by changing the length of the working electrode (WE, 2 cm) using the motor on the top of the working electrode in the three-electrode system (measurement range: 300mV~600mV, scan rate: 50mV). At this time, the length was stretched from 0% to 50% and measured by cyclic voltammetry.

Referring to Figures 5a and 5b, the area difference between the area of the black CV Cycle (0% strain) and the red CV cycle (50% strain) represents the difference in capacitance, and the area change ratio of each curve is the respective device Comparative Example 1-1 (30%) and Device Example 1 (22.6%). The capacitance change rate can be calculated through the area change rate. Additionally, the area of the electrochemical double layer formed by the carbon nanotube yarn composite within the electrolyte can be inferred through the rate of change of capacitance. Through the capacitance change rate of Device Comparative Example 1-1 and Device Example 1, it can be seen that the amount of change in the electrochemical double layer of Device Example 1 is smaller.

Test Example 2: Check OCV change amount

Figure 6 is a graph showing the amount of change in OCV of the energy harvester according to Device Example 1 and Device Comparative Example 1-1.

In the three-electrode system, the length of the working electrode (WE, 2 cm) was stretched from 0% to 50% using a motor on the top of the working electrode, and the sinusoidal OCV was measured. At this time, it is a graph obtained by extracting and plotting the OCV from the lowest point to the highest point.

Referring to Figure 6, the OCV change was shown in Device Comparative Example 1-1 (100mV) and Device Example 1 (97mV), respectively. It was found that Device Comparative Example 1-1 and Device Example 1 showed similar OCV changes due to the same tension.

Test Example 3: Power Analysis

Figure 7 is a graph showing the power of the energy harvester according to Device Example 2 and Device Comparative Example 2-1. Figure 8a is a schematic diagram of the generated power of the carbon nanotube yarn composite (CNT/AgNR) according to the present invention, and Figure 8b is a schematic diagram of the improved electron transfer structure of the carbon nanotube yarn composite (CNT/AgNR) according to the present invention.

In a two-electrode system, the resistance was changed in 30Ω increments from 30Ω to 420Ω, and the OCV was measured by stretching the working electrode (WE, 2cm) by 50% for each resistance using a motor on the top of the working electrode. Afterwards, the peak voltage is extracted and this is a graph showing the power using P=V ² /R.

Referring to FIG. 7, the power of the energy harvester was shown to be 180Ω (9.2μW) in Device Comparative Example 2-1 at 360Ω and 180Ω (9.2μW) in Device Example 2 at 180Ω, respectively. Therefore, it can be confirmed that the conductivity of the carbon nanotube yarn twisted by the metal nanorod is improved, and the performance is also improved due to the improved conductivity.

Also, referring to Figures 8a and 8b, it was found that the metal nanorod effectively improved the conductivity of the twisted carbon nanotube yarn and reduced the impedance matching resistance that produces maximum power. Additionally, it was confirmed that improved conductivity can also improve harvester performance.

Test Example 4: Comparison of capacitance of energy harvesters according to differences in manufacturing method

Figure 9 is a graph showing capacitance according to tension of energy harvesters using different manufacturing methods.

Cyclic voltammetry was measured by changing the length of the working electrode (WE, 2 cm) using the motor on the top of the working electrode in the three-electrode system (measurement range: 400mV~700mV, scan rate: 50mV). At this time, the length was discontinuously stretched by 2 mm (10%), cyclic voltammetry was measured, and capacitance was calculated. A total of 4 cycles were measured, and the capacitance was calculated using the last cycle.

According to Figure 9, the energy harvester according to Device Comparative Examples 1-1 and 1-2 using the twisted carbon nanotube yarn according to Comparative Example 1 (LAY-spinning) and Comparative Example 2 (Cone-spinning) as the working electrode has a capacitance The rate of change in (Capacitance) was 35.2% and 16.3%, respectively, confirming a difference of more than two times. In other words, by using LAY-spinning, which applies twist after arranging the yarn in the longitudinal direction (Longitudinally-Aligned yarn, LAY), the bias angles at both ends and the center appear similar, and the degree of twist on the surface is uniform. It was found that the performance of the energy harvester was better when using, and the yarn composite according to Example 1 manufactured using the LAY-spinning method could also show excellent performance when applied to the energy harvester.

Test Example 5: Comparison of energy harvester performance according to differences in manufacturing method

Figure 10 is a graph showing the peak voltage and gravimetric power of energy harvesters using different manufacturing methods.

In a two-electrode system, the variable resistance was changed in 30Ω increments from 30Ω to 420Ω, and OCV was measured by applying 80% tension as a 1Hz 4cycle sinusoidal wave through motor rotation. OCV was measured as a sine wave, and power (p=V ² /R) was calculated using the peak voltage.

According to Figure 10, the energy harvester according to Comparative Device Example 2-1 using the twisted carbon nanotube yarn of Comparative Example 1 (LAY-spinning) as a working electrode uses the twisted carbon nanotube yarn of Comparative Example 2 (Cone-spinning). It showed about 8 times improved performance compared to the energy harvester according to Comparative Example 2-2. In other words, using the LAY-spinning method, it was found that the energy harvester's performance was better when the bias angles at both ends and the center were similar and when using yarn with a uniform degree of surface twist, the LAY-spinning method was used. The yarn composite according to Example 1 prepared using can also show excellent performance when applied to an energy harvester.

Although the preferred embodiments of the present invention have been described above, those skilled in the art will be able to add, change, delete or modify components without departing from the spirit of the present invention as set forth in the patent claims. The present invention may be modified and changed in various ways by addition, etc., and this will also be included within the scope of rights of the present invention. For example, each component described as single may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form. The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

Claims (21)

delete delete delete delete delete delete delete delete delete delete delete delete delete (a) manufacturing a carbon nanotube sheet composite including a carbon nanotube sheet coated with metal nanorods by contacting a metal nanorod solution including metal nanorods on a carbon nanotube sheet including carbon nanotubes. ;
(b) preparing a washed carbon nanotube sheet composite by washing the carbon nanotube sheet composite with a polar solvent;
(c) lifting one end of the washed carbon nanotube sheet composite to manufacture a carbon nanotube sheet composite in which the carbon nanotubes and the metal nanorods are aligned in the longitudinal direction of the carbon nanotubes, respectively;
(d) applying twist to the longitudinally aligned carbon nanotube sheet composite to produce a longitudinally aligned carbon nanotube yarn composite; and
(e) manufacturing a twisted carbon nanotube yarn composite by further twisting the longitudinally aligned carbon nanotube sheet composite,
In step (b), the washed carbon nanotube sheet composite is a composite in which metal nanorods that are not aligned in the longitudinal direction of the carbon nanotubes have been removed. According to clause 14,
The method for producing the carbon nanotube yarn composite is between steps (d) and (e),
(d') additionally applying twist to the carbon nanotube yarn composite aligned in the longitudinal direction to produce a carbon nanotube yarn composite that is uniformly twisted along the longitudinal direction and has a bias angle of 20 to 56 degrees; A method for producing a carbon nanotube yarn composite, further comprising: delete According to clause 14,
A method of producing a carbon nanotube yarn composite, wherein the carbon nanotube sheet in step (a) includes multi-walled carbon nanotubes. According to clause 14,
A method of producing a carbon nanotube yarn composite, characterized in that the bias angle of the carbon nanotube yarn composite expressed by Equation 1 below is uniformly distributed along the length direction.
[Equation 1]
Bias angle (˚) = The angle formed between the longitudinal direction of the yarn and the twisting direction. According to clause 18,
A method of producing a carbon nanotube yarn composite, characterized in that the bias angle is 20 to 56 degrees. According to clause 14,
A method of producing a carbon nanotube yarn composite, characterized in that the carbon nanotube yarn composite aligned in the longitudinal direction of step (d) is in the form of a bundle including a plurality of carbon nanotubes aligned in the longitudinal direction. (1) manufacturing a carbon nanotube sheet cylinder by rolling a carbon nanotube sheet containing carbon nanotubes;
(2) twisting the carbon nanotube sheet cylinder to produce non-homogeneously twisted carbon nanotube yarn along the length direction;
(3) manufacturing a longitudinally aligned carbon nanotube yarn (LAY) by untwisting the carbon nanotube yarn that is unevenly twisted along the longitudinal direction;
(4) A carbon nanotube yarn aligned in the longitudinal direction, including a carbon nanotube yarn coated with metal nanorods by contacting the carbon nanotube yarn aligned in the longitudinal direction with a metal nanorod solution containing metal nanorods. Preparing a composite (longitudinally aligned carbon nanotube yarn composite, LAYC);
(5) twisting the carbon nanotube yarn composite aligned in the longitudinal direction to produce a homogeneously twisted carbon nanotube yarn composite along the longitudinal direction; and
(6) manufacturing a coiled carbon nanotube yarn composite by further twisting the uniformly twisted yarn composite along the longitudinal direction;
Method for producing a carbon nanotube yarn composite comprising: