KR102556903B1 - METHOD FOR MANUFACTURING FLEXIBLE MICROSUPERCAPACITOR DEVICE BY TRANSFERRING MXene ELECTRODE PATTERN TO LARGE AREA - Google Patents

Abstract

An embodiment of the present invention provides a high-performance micro-supercapacitor by utilizing a patterning method capable of high capacity and large area. A method for manufacturing a flexible micro-supercapacitor device by transferring a large-area MXene electrode pattern according to an embodiment of the present invention includes a first step of preparing a MXene solution; A second step of coating a photoresist mask on the substrate; A third step of coating the MXene solution on the photoresist mask; a fourth step of removing the photoresist mask from the substrate to form a MXene pattern, which is a MXene pattern on the substrate; A fifth step of coating a synthetic resin solution on the substrate on which the MXene pattern is formed and then heating it to form a film; and a sixth step of separating the film and the MXene pattern by removing the substrate to form a flexible element that is a combination of the film and the MXene pattern.

Description

Manufacturing method of flexible micro-supercapacitor device by transfer of large-area MXene electrode pattern

The present invention relates to a method for manufacturing a flexible micro-supercapacitor device by transferring a large-area MXene electrode pattern, and more particularly, to a technique for manufacturing a high-performance micro-supercapacitor by utilizing a patterning method capable of high capacity and large area. it's about

BACKGROUND OF THE INVENTION The rapid development of miniaturized electronic devices is increasing the demand for miniaturized on-chip energy storage devices. Micro-supercapacitors have great potential to complement and replace conventional batteries and electrolytic capacitors due to their many advantages, such as fast charge/discharge rate, high power, and unlimited lifetime.

However, in the conventional micro-supercapacitor manufacturing technology, it is cumbersome to construct micro-scale electrodes in terms of cost-effectiveness, and wide application of micro-supercapacitors is impossible due to limitations in large-area fabrication. Accordingly, recently, supercapacitors using MXene showing excellent performance in energy storage devices due to high conductivity and excellent electrochemical properties have been developed.

A conventional micro-supercapacity was prepared by forming a MXene film on a glass or plastic substrate using a dip-coating method, and using a pattern using a physical scratching method as an electrode on the MXene film.

This manufacturing method is characterized in that it can be patterned in various shapes and can manufacture flexible micro-supercapacitors using flexible substrates. However, since the conventional manufacturing method as described above is a direct-write method in the form of automated scalpel engraving after dip coating, there is a problem in that it is difficult to large-area and takes a lot of time to manufacture a micro-supercapacitor. In addition, it is dependent on the scalpel machining technique, resulting in low resolution. In particular, there was a problem that the device efficiency was lowered as the interelectrode spacing of the manufactured micro-supercapacitor was about 200 μm. Therefore, there is a need for a micro-supercapacitor manufacturing technology that is easy to have a high capacity and a large area.

Scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage (Nature communications (2013, 4;1475))

An object of the present invention to solve the above problems is to provide a micro-supercapacitor manufacturing method using a solution process for manufacturing a high-performance micro-supercapacitor by utilizing a patterning method capable of high capacity and large area, and a manufacturing method thereof. To provide a manufactured micro-supercapacitor.

The technical problem to be achieved by the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

The configuration of the present invention for achieving the above object is a first step of preparing a MXene solution; A second step of coating a photoresist mask on the substrate; a third step of coating the MXene solution on the photoresist mask; a fourth step of removing the photoresist mask from the substrate to form a MXene pattern that is patterned MXene on the substrate; a fifth step of coating a synthetic resin solution on the substrate on which the MXene pattern is formed and then heating it to form a film; and a sixth step of separating the film and the MXene pattern by removing the substrate to form a flexible element that is a combination of the film and the MXene pattern.

In an embodiment of the present invention, the synthetic resin solution is a polyimide solution, and the film may be formed of polyimide.

In an embodiment of the present invention, in the fifth step, primary heating may be performed at a temperature of 50 to 100 degrees (° C.) on the coating layer formed by coating the polyimide solution on the substrate.

In an embodiment of the present invention, in the fifth step, the coating layer is imidized by performing secondary heating at a temperature of 250 to 350 degrees (° C.) on the primary heated coating layer to imidize the film. can form.

In an embodiment of the present invention, in the fifth step, the coating of the polyimide solution on the substrate may be performed by dip coating or spin coating.

In an embodiment of the present invention, the substrate may be a SiO ₂ layer formed on a silicon wafer.

In an embodiment of the present invention, in the sixth step, the substrate may be removed by hydrogen fluoride (HF) etching.

In an embodiment of the present invention, in the fourth step, the photoresist mask may be removed by using an acetone solvent in an ultrasonic cleaner.

In an embodiment of the present invention, in the first step, MAXene may be obtained by etching the MAX phase under LiF+HCL 6M conditions.

In an embodiment of the present invention, the thickness of the film may be 0.1 to 5 micrometers (㎛).

In an embodiment of the present invention, a plurality of flexible elements may be connected in series or parallel.

The effect of the present invention according to the configuration as described above is that a micro-supercapacitor can be manufactured using an easy and simple solution process method, and mass-production and large-area micro-supercapacitors are possible.

In addition, the effect of the present invention is that it is possible to provide a microsupercapacitor that can be applied to various applications in which the shape is deformed, such as a roll-up display and a wearable device, by forming a patterned MXene on the surface of a film of a flexible material.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a schematic diagram of a process for forming MXene patterns according to an embodiment of the present invention.
Figure 2 is a schematic diagram of a process for coating MXene solution according to an embodiment of the present invention.
3 is an image of a MXene pattern on a wafer according to an embodiment of the present invention.
4 is an image of a MXene pattern according to an embodiment of the present invention.
5 is an image showing the shape of a MXene pattern according to an embodiment of the present invention.
6 is a SEM image of MXene patterns according to an embodiment of the present invention.
7 is a schematic diagram of formation of MXene patterns on a substrate according to an embodiment of the present invention.
8 is a schematic diagram of the formation of a film according to an embodiment of the present invention.
9 is a schematic diagram of an etching process according to an embodiment of the present invention.
10 is a schematic diagram of formation of a flexible element according to an embodiment of the present invention.
11 and 12 are images of a flexible element according to an embodiment of the present invention.
13 is a CV curve graph for each of a substrate having a MXene pattern and a flexible device according to an embodiment of the present invention.
14 is a graph showing volumetric capacitance values according to scan speeds of a substrate having a MXene pattern and a flexible element according to an embodiment of the present invention.
15 and 16 are graphs showing Galvanostatic charge-discharge (GCD) characteristics of a substrate having a MXene pattern and a flexible device, respectively, according to an embodiment of the present invention.
17 is an image of bending of a flexible element according to an embodiment of the present invention.
18 is a CV curve graph according to a degree of bending of a flexible element according to an embodiment of the present invention.
19 is a graph showing volumetric capacity values according to bending degrees of a flexible element according to an embodiment of the present invention.
20 to 25 are graphs showing cyclic voltammetry characteristics according to the degree of bending of a flexible element according to an embodiment of the present invention.
26 is a graph showing volumetric capacity values according to bending degrees of a flexible element according to an embodiment of the present invention.
27 is a CV curve graph according to the number of bending times of a flexible element according to an embodiment of the present invention.
28 is a graph of a capacitance retention rate according to the number of bending times of a flexible element according to an embodiment of the present invention.
29 is a CV curve graph according to the number of charge/discharge cycles of a flexible device according to an embodiment of the present invention.
30 is a graph of a capacitance retention rate according to the number of charge/discharge cycles of a flexible device according to an embodiment of the present invention.
31 is a CV curve graph according to whether flexible elements are connected in series or in parallel according to an embodiment of the present invention.
32 is a graph showing Galvanostatic charge-discharge (GCD) characteristics according to whether flexible devices are connected in series or in parallel according to an embodiment of the present invention.
33 is a graph showing Galvanostatic charge-discharge (GCD) characteristics according to whether flexible elements are connected in parallel according to an embodiment of the present invention.
34 is a graph showing Galvanostatic charge-discharge (GCD) characteristics according to whether or not flexible elements are connected in series according to an embodiment of the present invention.
35 is a graph of capacitance change according to the number of parallel connections of flexible elements according to an embodiment of the present invention.
36 is a CV curve graph according to whether flexible elements are connected in series or in parallel according to an embodiment of the present invention.
37 is a CV curve graph when a plurality of flexible elements are connected in parallel according to an embodiment of the present invention.
38 is a graph showing capacitance change according to scan speed when a plurality of flexible elements are connected in parallel according to an embodiment of the present invention.
39 is a table summarizing materials and properties of flexible devices and other comparative devices according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms, and therefore is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this is not only "directly connected", but also "indirectly connected" with another member in between. "Including cases where In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "include" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of a process for forming MXene patterns 140 according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a process of coating MXene solution 130 according to an embodiment of the present invention. .

3 is an image of a MXene pattern 140 on a wafer 150 according to an embodiment of the present invention, and FIG. 4 is an image of a MXene pattern 140 according to an embodiment of the present invention. 5 is an image showing the shape of the MXene pattern 140 according to an embodiment of the present invention. And, FIG. 6 is a SEM image of MXene pattern 140 according to an embodiment of the present invention.

In addition, FIG. 7 is a schematic diagram of the formation of the MXene pattern 140 on the substrate 110 according to an embodiment of the present invention, and FIG. 8 is a schematic diagram of the formation of the film 160 according to an embodiment of the present invention. 9 is a schematic diagram of an etching process according to an embodiment of the present invention. And, Figure 10 is a schematic diagram of the formation of the flexible element 10 according to an embodiment of the present invention.

In addition, (a) of FIG. 6 is for a case where the resolution is 500 micrometers (μm), (b) of FIG. 6 is for a case where the resolution is 100 micrometers (μm), and (c) of FIG. is for the case where the resolution is 10 micrometers (μm).

7 (a) is a plan view of the wafer 150 on which a plurality of MXene patterns 140 are formed, and FIG. 7 (b) is a perspective view of the wafer 150 on which a plurality of MXene patterns 140 are formed. am. In addition, FIG. 8(a) is a plan view of a wafer 150 and a film 160 assembly on which a plurality of MXene patterns 140 are formed, and FIG. 8(b) is a wafer on which a plurality of MXene patterns 140 are formed ( 150) and the film 160 is a perspective view of the assembly.

10(a) relates to the separation of the film 160 and MXene pattern 140 from the substrate 110 by removing the substrate 110, and FIG. 10(b) shows the flexible element 10 It is about the matters formed.

In the manufacturing method of the present invention, first, a first step of preparing MXene solution 130 may be performed. Here, the first step may include a 1-1 step of obtaining MXene and a 1-2 step of forming MXene solution 130 by mixing the obtained MXene with distilled water.

In step 1-1, it may be prepared to synthesize MAX and MXene. As a specific example, MAXene may be obtained by etching the MAX phase under LiF+HCL 6M conditions.

In step 1-2, the obtained MXene is mixed with distilled water, and the MXene solution 130 may refer to a solution obtained by mixing distilled water with a predetermined concentration. Specifically, the MXene solution 130 may be prepared by adding distilled water so that the MXene concentration in the MXene solution 130 is 5-15 mg/ml.

After performing the first step described above, a second step of coating the photoresist mask 120 on the substrate 110 may be performed. Here, the substrate 110 may be a SiO ₂ layer formed on a silicon wafer (Si wafer). However, the type of substrate 110 is not limited thereto.

The SiO ₂ layer may be formed by oxidizing the surface of a silicon wafer (Si wafer), and each process related to the substrate 110 below is for the SiO ₂ layer on the wafer 150 and is a process using the wafer 150. In the following description, for convenience of understanding, the substrate 110 (SiO ₂ layer) will be described as a reference.

The photoresist mask 120 may be of a negative type. More specifically, the photoresist mask 120 has a width of 50 micrometers (μm) at the perforated portion where the microelectrodes are formed, The thickness may be formed to be 3.5 micrometers (㎛).

The above numerical values are the most preferred embodiments, and in the present invention, the numerical values are not limited to one embodiment. In the present invention, the width of the perforated part of the part where the microelectrode is formed is 45 to 55 micrometers (㎛), the interval between the perforated parts of the part where the microelectrode is formed is 45 to 55 micrometer (㎛), and the thickness is 3 to 5 It includes micrometers (μm). The shape of the perforated portion of the photoresist mask 120 corresponds to the shape of the MXene pattern 140 to be formed later, and its more specific shape will be described later.

After performing the second step described above, a third step of coating the MXene solution 130 on the photoresist mask 120 may be performed. Here, dip coating or spin coating may be performed to coat the MXene solution 130 on the substrate 110 coated with the photoresist mask 120 .

Dip coating is provided to perform coating at a speed of 0.95 to 1.05 μm/s, preferably 1 μm/s, and during spin coating, coating is performed under conditions of 300 rpm to 1,000 rpm and 100 to 300 seconds. It can be.

As shown in FIG. 2, in the case of using Dip coating, the substrate 110 coated with the photoresist mask 120 is supported in a water tank containing the MXene solution, and the MXene solution 130 is formed in the empty space within the photoresist mask 120. can be coated. Accordingly, the MXene solution 130 may be coated on the substrate 110 in a pattern corresponding to the shape of the photoresist mask 120 .

After performing the above-described third step, a fourth step may be performed in which the photoresist mask 120 is removed from the substrate 110 to form the MXene pattern 140 , which is a patterned MXene on the substrate 110 .

Specifically, the photoresist mask 120 may be removed by an acetone solvent while staying in an ultrasonic cleaner for 30 seconds to 5 minutes after a baking process is performed at 120 degrees for 30 minutes. At this time, the baking process of the photoresist mask 120 may be performed within a range of 110 to 130 degrees and 25 to 35 minutes.

Here, distilled water is evaporated from the MXene solution 130 coated in a predetermined pattern by the baking process as described above, and thus, the MXene pattern 140, which is a patterned MXene, can be formed on the substrate 110.

As shown in FIG. 3 , a plurality of MXene patterns 140 may be formed on the substrate 110, that is, a plurality may be manufactured using one wafer 150, and as such, a plurality of MXene patterns may be formed on a large area. Since the MXene pattern 140 can be formed, manufacturing efficiency can be remarkably increased.

As shown in FIG. 4, when Dip coating or Spin coating is used using the SiO ₂ substrate 110 patterned by photolithography, a uniform MXene solution 130 coating layer is formed without being affected by the existing pattern. and can obtain MXene patterned on a micro scale.

Referring to FIG. 5 , the shape of the MXene pattern 140 manufactured according to the manufacturing method of the present invention will be described in detail.

The MXene pattern 140 includes a first body 141, a second body 142, a first extension 143, a second extension 144, a first electrode 145, and a second electrode 146. ) may be included. The first body portion 141 and the second body portion 142 are spaced apart from both side surfaces of the substrate 110 at equal intervals and may extend long in the width direction of the substrate 110 . Also, the first body portion 141 and the second body portion 142 may be formed symmetrically with respect to the center line of the substrate 110 and spaced apart from each other.

The first extension part 143 may extend upward from the first body part 141 , and the second extension part 144 may extend upward from the second body part 142 . Here, outer surfaces of the first extension part 143 and the second extension part 144 may be provided to be formed at a point dividing the substrate 110 into thirds. Also, the first extension 143 and the second extension 144 are spaced apart from each other to form a space in which a microelectrode can be formed between the first extension 143 and the second extension 144. can be arranged so that

The first electrode 145 extends from the first extension 143 toward the second extension 144, one end extending with the first extension 143, and the other end extending with the second extension 144. It can be formed spaced apart from. The second electrode 146 extends from the second extension part 144 toward the first extension part 143, one end extends with the second extension part 144, and the other end extends with the first extension part 143. It can be formed spaced apart from.

The first electrode 145 and the second electrode 146 are formed at regular intervals, and may be arranged to cross each other between the first extension part 143 and the second extension part 144 . At this time, the interval between the first electrode 145 and the second electrode 146 and the width of the first electrode 145 and the second electrode 146 are formed to be 45 to 55 μm, but a uniform interval and width can be formed to have In addition, the first electrode 145 and the second electrode 146 may have a thickness of 3 to 5 μm and may be formed with a uniform thickness.

As shown in FIG. 6 , in the prepared micro-supercapacitor, it can be confirmed that the intervals and widths of the MXene patterns 140 are uniform.

After the fourth step described above, as shown in FIGS. 7 and 8 , a fifth step of forming a film 160 by coating a synthetic resin solution on the substrate 110 on which the MXene pattern 140 is formed is performed, and then heated. It can be.

Here, the synthetic resin solution is a polyimide solution, and the film 160 may be formed of polyimide. In the embodiment of the present invention, it is described that the material of the film 160 is formed as described above, but it is not limited thereto, and other synthetic resin materials other than polyimide may be used.

In the fifth step, coating of the polyimide solution on the substrate 110 may be performed by dip coating or spin coating. Dip coating is provided to perform coating at a speed of 0.95 to 1.05 μm/s, preferably 1 μm/s, and during spin coating, coating is performed under conditions of 1,500 rpm to 2,500 rpm, 20 seconds to 70 seconds It can be.

Preferably, spin coating may be performed for coating the polyimide solution, and spin coating may be performed at a speed of 2,000 rpm for 50 seconds.

As described above, the polyimide solution can be uniformly coated on the substrate 110 on which the MXene pattern 140 is formed by the coating, and thus the surface of the film 160 and the MXene pattern 140 are formed. ) can be increased while the binding force is uniform.

In the fifth step, the coating layer formed by coating the substrate 110 with the polyimide solution may be subjected to primary heating at a temperature of 50 to 100 degrees (°C). And, in the fifth step, by performing secondary heating at a temperature of 250 to 350 degrees (° C.) on the primary heated coating layer, the coating layer may be imidized to form a film 160 .

The primary heating as described above is heating performed toward the film 160 from the ambient of the film 160, and may be performed for 20 to 40 minutes (min). Preferably, the first heating (soft-baking) may be performed at a temperature of 80 degrees (° C.) for 30 minutes (min).

The polyimide coating layer on the substrate 110 may be bonded to the substrate 110 and the MXene pattern 140 by the primary heating as described above, and the polyimide coating layer may form the shape of the film 160 by the primary heating. It is cured to form a film 160.

After that, secondary heating may be performed to perform imidation annealing on the film 160, and secondary heating may be performed for 50 to 130 degrees min in the above temperature range. The same secondary heating may be performed under an inert gas atmosphere such as argon (Ar) gas in a furnace.

The thickness of the film 160 may be 0.1 to 5 micrometers (μm). By forming the film 160 to such a thickness, a flexible and thin film 160 having elasticity can be formed. As a result, the flexible element 10, which is the film 160 having the MXene pattern 140, can be used for roll-up displays, e-paper, smart sensors, transparent RFID, wearable devices, etc. Efficiency in large-area applications can be increased.

After performing the fifth step described above, the substrate 110 is removed to separate the film 160 and the MXene pattern 140 to form the flexible element 10, which is a combination of the film 160 and the MXene pattern 140. A sixth step may be performed. Here, as shown in FIGS. 9 and 10 , in the sixth step, the substrate 110 may be removed by hydrogen fluoride (HF) etching. That is, the flexible element 10, which is the film 160 having the MXene pattern 140, may be delaminated from the substrate 110.

Hydrogen fluoride (HF) etching can be performed by immersing the combination of the substrate 110 and the film 160 on which the MXene pattern 140 is formed in a water tank in which hydrogen fluoride (HF) at a concentration of 49% is stored. At this time, The etching time may be performed for 3 to 7 minutes (min), preferably, it may be performed for 5 minutes (min).

After forming the film 160 on the substrate 110 as described above, when the film 160 is separated from the substrate 110, the MXene pattern 140 is transferred to the film 160 and is used as a flexible micro-supercapacitor. Device 10 can be obtained.

Here, the substrate 110 on which the MXene pattern 140 is formed can also be used as a micro-supercapacitor, but the flexible element 10 formed as described above is easily attached to a surface having elasticity due to its high flexibility and elasticity. Elastic shape deformation (bending, twisting, rolling, etc.) is possible to correspond to the deformation of the surface having a surface.

Using the flexible device 10 formed as described above, a plurality of flexible devices 10 may be connected in series or parallel. Even when one flexible element 10 and another flexible element 10 are connected, the same process as described above may be performed.

Specifically, after forming a plurality of separate MXene patterns 140 on the substrate 110 and forming a MXene of a connection pattern connecting each MXene pattern 140, each pattern is formed on a film 160 as described above. ) can be transcribed. And, by removing each part of the film 160 to be divided into each flexible element 10, it is possible to manufacture a plurality of flexible elements 10 connected in series or in parallel. Accordingly, it is possible to shorten the manufacturing time of the plurality of flexible elements 10 connected to each other.

However, the connection method of each flexible element 10 is not limited to the above method, and it is natural that each flexible element 10 can be connected using a metal nano wire or the like. By implementing the effect of series connection or parallel connection of micro supercapacitors by the connection as described above, it is possible to expand the application range of the flexible element 10 of the present invention.

That is, in actual devices (electronic devices), specific capacitance and voltage are required, and 90 to 100 flexible elements 10 are manufactured using the 8-inch wafer 150 by the above process, By connecting each of the flexible elements 10, various capacities and voltages can be implemented.

11 and 12 are images of the flexible element 10 according to an embodiment of the present invention. Here, (a) of FIG. 11 is an image of one flexible element 10, and (b) of FIG. 11 is an image of the flexible element 10 attached to the back of a person's hand. Further, FIG. 12 (a) is an image of the matter of deforming the flexible element 10 attached to the back of a person's hand, and FIG. 12 (b) is an image of the rolled flexible element 10.

As shown in FIGS. 11 and 12, the flexible element 10 of the present invention is in the form of a thin film 160 formed of synthetic resin, and is not only free to deform, but also has an electrode pattern, that is, a MXene pattern 140 even when wound or bent. ) is prevented, and the performance is maintained even when attached to a flexible surface.

13 is a cyclic voltammetry (CV) curve graph for each of the flexible device 10 and the substrate 110 having the MXene pattern 140 according to an embodiment of the present invention. In FIG. 13, graph a is for the substrate 110 (including the wafer 150, the same below) on which the MXene pattern 140 is formed, and graph b is for the flexible element 10 of the present invention.

As shown in FIG. 13 , both the substrate 110 on which the MXene pattern 140 is formed and the flexible device 10 show ideal rectangular CV curves at a scan rate of 10 mV/s and similar graph patterns. And, a performance improvement of about 20% was shown at a scan rate of 10 mV/s. (substrate 110 on which MXene pattern 140 is formed: 1218.2 F/cm ³ , flexible device 10: 1472.7 F/cm ³ )

This is a phenomenon that appears as the wettability of the electrolyte on the film 160 is improved rather than the wettability of the electrolyte on the substrate 110, as the base on which the MXene pattern 140 is formed is changed by transfer from the substrate 110 to the film 160, that is, , It may be a phenomenon caused by improvement of the film quality as the base performing the electrolyte function is changed from the substrate 110 to the film 160.

Specifically, it may be because hydrogen fluoride (HF) used during the transfer process affects the surface state of MXene with respect to the functional group of MXene, which enhances the mobility of ions, thereby Dosage may be increased.

14 is a graph showing volumetric capacitance values according to scan speeds of the substrate 110 having the MXene pattern 140 and the flexible device 10 according to an embodiment of the present invention.

As shown in FIG. 14, when the volumetric capacitance is calculated through the CV curve of the flexible device 10, the MXene pattern 140, which is a graph of square dots, shows values at each scan speed. As can be seen in the comparison of the graph for the substrate 110 formed with the graph and the graph for the flexible element 10, which is a graph of circular dots, the flexibility of the present invention is generally compared to the substrate 110 on which the MXene pattern 140 is formed. It can be seen that the capacitance of the element 10 is increased.

15 and 16 are graphs showing respective galvanostatic charge-discharge (GCD) characteristics of the substrate 110 having the MXene pattern 140 and the flexible device 10 according to an embodiment of the present invention. A graph in FIG. 15 and a square dot graph in FIG. 16 are graphs for the substrate 110 having MXene patterns 140, and graph b in FIG. 15 and a circular dot graph in FIG. 16 are for the flexible element 10. it's a graph 15 and 16, it can be confirmed that the capacitance of the flexible device 10 of the present invention is increased compared to the substrate 110 on which the MXene pattern 140 is formed. Specifically, at a scan rate of 10 mV/s, about It showed a performance improvement of 12%. (substrate 110 on which MXene pattern 140 is formed: 1275.7 F/cm ³ , flexible element 10: 1436.4 F/cm ³ )

17 is an image of bending of the flexible element 10 according to an embodiment of the present invention. FIG. 17 (a) is an image of a state in which the flexible element 10 is maintained in an unfolded state, and (b) in FIG. 17 is an image in which the flexible element 10 is bent (radius: 5.27 mm). ) is an image of the items kept.

18 is a CV curve graph according to a degree of bending of the flexible element 10 according to an embodiment of the present invention. And, FIG. 19 is a graph showing the volumetric capacity value according to the degree of bending of the flexible element 10 according to an embodiment of the present invention.

In FIG. 18, while varying the degree of bending of the flexible element 10 (flat, 3.87mm, 4.25mm, 5.27mm, 6.53mm, 8.58mm), measurement was performed at a scan speed of 10 mV/s, and in FIG. 19 , 10 mV while changing the degree of bending of the substrate 110 (Si) and the flexible element 10 on which the MXene pattern 140 is formed (flat, 3.87mm, 4.25mm, 5.27mm, 6.53mm, 8.58mm) Measurements were performed at /s scan rate.

As shown in FIGS. 18 and 19 , it can be confirmed that the performance of the flexible element 10 is maintained even if the flexible element 10 of the present invention is bent, and thus, damage to the MXene pattern 140 is prevented even when the shape is deformed. While being prevented, it can be confirmed that the micro-supercapacitor function of the flexible element 10 is implemented.

20 to 25 are graphs showing cyclic voltammetry characteristics according to the degree of bending of the flexible element 10 according to an embodiment of the present invention. Each graph shows CV characteristics at various scan speeds (10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000 mV/s) according to the degree of bending of the flexible element 10. This is the result.

And, FIG. 26 is a graph showing the volumetric capacity value according to the degree of bending of the flexible element 10 according to an embodiment of the present invention. In FIG. 26, graphs according to the degree of bending of the flexible element 10 are classified in a dot shape of the graph.

20 is a graph of the flexible element 10 in a flat state, FIG. 21 is a graph of the flexible element 10 bent to a radius of 3.87 mm, and FIG. 22 is a graph of the flexible element 10 bent to a radius of 4.25 mm ( 10), and FIG. 23 is a graph of the flexible element 10 bent to a radius of 5.27 mm. 24 is a graph of the flexible element 10 bent to a radius of 5.27 mm, and FIG. 25 is a graph of the flexible element 10 bent to a radius of 5.27 mm.

As shown in FIGS. 20 to 26 , each graph shows a similar shape even when the shape of the flexible element 10 is deformed. Therefore, it can be confirmed that the performance of the flexible element 10 is maintained even if the flexible element 10 of the present invention is bent, and thus, damage to the MXene pattern 140 is prevented even when the shape is deformed, and the It can be confirmed that the micro-supercapacitor function is implemented.

27 is a CV curve graph according to the number of times of bending of the flexible element 10 according to an embodiment of the present invention. Here, graphs for the results of testing the CV characteristics of the flexible element 10 at a scan rate of 50 mV/s are shown, and each graph is a graph according to the number of times of bending (200, 500, and 1000 times). And, FIG. 28 is a graph of the capacitance retention rate according to the number of times of bending of the flexible element 10 according to an embodiment of the present invention. 27 and 28, the bending radius of the flexible element 10 is set to 5.27 mm.

As shown in FIG. 27, it can be confirmed that an ideal rectangular CV curve is formed even after 1000 bendings, and the change in each bending number graph is minimized to maintain performance. And, as shown in FIG. 28, it can be confirmed that the capacity level of 98.8% is maintained even after 1000 bendings.

29 is a CV curve graph according to the number of charge/discharge cycles of the flexible element 10 according to an embodiment of the present invention. Here, graphs are shown for the results of testing the CV characteristics of the flexible element 10 at a scan rate of 50 mV/s, and each graph shows the number of charge/discharge cycles (1, 10, 50, 100, 5000, 1000 times). It is the following graph. 30 is a graph of the capacitance retention rate according to the number of charge/discharge cycles of the flexible element 10 according to an embodiment of the present invention. 27 and 28, the bending radius of the flexible element 10 is set to 5.27 mm.

As shown in FIG. 29, it can be seen that an ideal rectangular CV curve is formed even after 1000 charge/discharge cycles, and the change in each charge/discharge number graph is minimized to maintain performance. And, as shown in FIG. 30 , it can be confirmed that the capacity level of 93.8% is maintained even after 1000 charge/discharge cycles.

31 is a CV curve graph according to whether flexible elements 10 are connected in series or in parallel according to an embodiment of the present invention. Here, it is the result of an experiment at a scan rate of 10 mv/s for the flexible element 10 or the flexible element 10 connection body according to each connection method.

And, in FIG. 31, the single graph shows the CV curve for a single flexible element 10, and the 4-Series (4S) graph shows the CV curve for a connection body connecting four flexible elements 10 in series. 4-Parallel (4P) graph may represent a CV curve for a connection body in which four flexible elements 10 are connected in parallel. In addition, the 2-Series-2-Parallel (2S2P) graph may represent a CV curve for a connection body in which two flexible elements 10 are serially connected unit connectors connected in parallel.

As shown in FIG. 31 , a required voltage may be implemented using a series connection of the flexible devices 10 and a required capacitance may be implemented using a parallel connection of the flexible devices 10 . Specifically, it can be confirmed that the output voltage is increased four times from 0.6V to 2.4V by the 4-series connection of the flexible element 10 . In addition, by the 4-parallel connection of the flexible element 10, the output current is improved, and it can be confirmed that the capacity is linearly increased by about 4 times.

32 is a graph showing Galvanostatic charge-discharge (GCD) characteristics according to whether flexible devices 10 are connected in series or parallel according to an embodiment of the present invention, and FIG. 33 is a graph showing a flexible device according to an embodiment of the present invention. 34 is a graph showing the characteristics of Galvanostatic charge-discharge (GCD) according to whether or not (10) is connected in parallel, and FIG. ) is a graph showing the characteristics.

Details on the display of graphs (Single, 4-Series (4S), 4-Parallel (4P), 2-Series-2-Parallel (2S2P)) according to each connection in FIG. 31 as described above are described below. The same can be applied to FIGS. 32 to 34 .

In each of FIGS. 32 to 34 , GCD characteristics were analyzed for each connector at a current of 5 μA. As shown in the comparison of each graph in FIGS. 32 to 34, when the flexible device 10 is connected in 4-series, it can be confirmed that the output voltage increases 4 times from 0.6V to 2.4V, and the flexible device 10 ) is connected 4-parallel, it can be confirmed that the capacity has increased about 4 times along with the improvement of the output current.

35 is a graph of capacitance change according to the number of parallel connections of flexible devices 10 according to an embodiment of the present invention, and FIG. 36 is a series or parallel of flexible devices 10 according to an embodiment of the present invention. This is a CV curve graph depending on whether or not it is connected. In the experiment related to FIG. 36, the CV characteristics were tested by setting the scan rate to 10 mV/s for each connector.

As shown in FIG. 35 , as the number of parallel connections of the flexible elements 10 increases, the capacity of the flexible element 10 connected body tends to increase linearly. That is, it can be confirmed that the output current shows a linear increase along with the increase in the number of (parallel) parallel connections.

As shown in FIG. 36, it can be confirmed that the capacitance increased to 1.15, 1.77, 3.61, 6.05, 8316, 9.17, and 11.7 mF at a scan rate of 10 mV/s as the number of parallel connections increased. Accordingly, it can be confirmed that the capacitance required for application to an actual electronic device is met without resistance through parallel connection.

37 is a CV curve graph when a plurality of flexible elements 10 are connected in parallel according to an embodiment of the present invention, and FIG. 38 is a graph showing a plurality of flexible elements 10 connected in parallel according to an embodiment of the present invention. In this case, it is a graph showing capacitance change according to scan speed.

37 and 38 are graphs of CV characteristics and capacitance in the case of forming a 12-connected body in which 12 flexible elements 10 are connected in parallel. And, in FIG. 37, each graph was tested for CV characteristics at various scan rates (10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000 mV/s) for the above-described 12-connected body. is a result In addition, in FIG. 38, the capacitance change was measured while the scan rate was changed from 10 mV/s to 10,000 mV/s, and the capacitance change was 11.7, 11.6, 11.0, 10.1, 8.6, 5.6, 3.0, 1.3, 0.18, 0.16 mF.

Unlike the inkjet printing method, the method of manufacturing the flexible element 10 of the present invention, which is a micro-supercapacitor, by the above process does not require an additional process for producing ink, and compared to the inkjet printing and laser methods, the size is 50 μm or less. It may be possible to implement a fine pattern of

In the case of substrates (films) made of flexible materials, most of them are plastic materials (polymer series) that are vulnerable to heat, so there is a disadvantage that thin film processes on flexible substrates are limited. However, in the case of HF etching, all processes are possible on SI wafers. , After that, it can be transferred to a flexible substrate (PDMS, PI, etc.) and used as a flexible device 10.

The transfer method using HF etching has a limitation that the target material is limited due to HF (strong acid). can be suitable as In particular, as shown above, it can be confirmed that the effect of improving the characteristics of the MXene pattern 140 (MXene thin film) after transfer is realized.

That is, according to the manufacturing method of the flexible element 10 of the present invention, the problem of mass production due to the slow process speed, which is a limitation of laser printing, and the problem of additional process/additive and line width limitation for ink production, which is a limitation of inkjet printing, are solved. can be solved at the same time. In addition, the characteristics of the fabricated flexible device 10 (Mxene microsupercapacitor device) also have a very excellent advantage.

39 is a table summarizing materials and properties of the flexible element 10 and other comparison elements according to an embodiment of the present invention.

As shown in FIG. 39, when using the flexible device (Our Work) 10 of the present invention, it is confirmed that a relatively thin thickness (80 nm) can be implemented and a high capacity (1436.4 F/cm ³ ) can be implemented. can In addition, the maximum energy consumption is 41.96 (mWh/cm ³ ) and the maximum power is 26.8 (W/cm ³ ), which is far superior to the measured values of the other comparative devices (1 to 18).

Also, in terms of bending durability, as shown in each numerical comparison, it can be confirmed that it is superior compared to other comparative elements 1 to 18.

In conclusion, when using the flexible device (Our Work) 10 of the present invention, it can be confirmed that the device efficiency is excellent and the wearable characteristics are excellent.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

10: flexible element
110: substrate
120: photoresist mask
130: MXene solution
140: Maxine pattern
141: first body part
142: second body
143: first extension
144: second extension
145: first electrode
146: second electrode
150: wafer
160: film

Claims (12)

A first step of preparing MXene solution;
A second step of coating a negative type photoresist mask on the substrate;
a third step of coating the photoresist mask with the MXene solution to form patterned MXene on the surface of the substrate so that the lower surface of the patterned MXene layer is in contact with the surface of the substrate;
a fourth step of removing the photoresist mask from the substrate to form a MXene pattern that is patterned MXene on the substrate;
a fifth step of coating a synthetic resin solution on the substrate on which the MXene pattern is formed and then heating it to form a film; and
A sixth step of removing the substrate to separate the film and the MXene pattern to form a flexible element that is a combination of the film and the MXene pattern;
The coating in the third step is performed by dip coating or spin coating, and coating is performed at a speed of 0.95 to 1.05 μm/s during dip coating, and under conditions of 300 rpm to 1,000 rpm and 100 to 300 seconds during spin coating. coating is performed;
In the fourth step, after the baking process is performed on the photoresist mask, the photoresist mask is removed by an acetone solvent in an ultrasonic cleaner. manufacturing method.
The method of claim 1,
Wherein the synthetic resin solution is a polyimide solution, and the film is formed of polyimide.
The method of claim 2,
In the fifth step, the coating layer formed by coating the polyimide solution on the substrate is subjected to primary heating at a temperature of 50 to 100 degrees (℃) by transferring the large-area MXene electrode pattern. Manufacturing method of flexible micro-supercapacitor device.
The method of claim 3,
In the fifth step, by performing secondary heating at a temperature of 250 to 350 degrees (° C.) on the first heated coating layer, thereby imidizing the coating layer to form the film. Manufacturing method of flexible micro-supercapacitor device by transfer of area Maxine electrode pattern.
The method of claim 3,
In the fifth step, the coating of the polyimide solution on the substrate is performed by dip coating or spin coating.
The method of claim 5,
The substrate is a flexible micro-supercapacitor device manufacturing method by transferring a large-area MXene electrode pattern, characterized in that the SiO ₂ layer formed on a silicon wafer (Si wafer).
The method of claim 5,
In the sixth step, the substrate is removed by hydrogen fluoride (HF) etching, characterized in that the flexible micro-supercapacitor device manufacturing method by transferring the large-area MXene electrode pattern.
delete The method of claim 1,
In the first step, the method of manufacturing a flexible micro-supercapacitor device by transferring a large-area MXene electrode pattern, characterized in that MAXene is obtained by etching the MAX phase under LiF + HCL 6M conditions.
The method of claim 1,
The thickness of the film is 0.1 to 5 micrometers (μm).
The method of claim 1,
A method for manufacturing a flexible micro-supercapacitor device by transferring a large-area MXene electrode pattern, characterized in that a plurality of flexible devices are connected in series or parallel.
A flexible micro-supercapacitor device manufactured by the method for manufacturing a flexible micro-supercapacitor device by transferring a large-area MXene electrode pattern according to any one of claims 1 to 7 and 9 to 11.