KR20210106332A - Secondary battery with bending structure, and method of fabricating of the sames - Google Patents

Abstract

A secondary battery is provided. The secondary battery includes a positive electrode, a solid electrolyte, and a negative electrode, wherein a stack structure comprising the positive electrode and the solid electrolyte stacked together is provided, the stack structure is bent to provide a bending region therebetween, and the negative electrode is provided within the bending region. The present invention provides the secondary battery having a bending structure having a low manufacturing cost and a simple manufacturing process, and a manufacturing method thereof.

Description

Secondary battery having a bending structure, and a method for manufacturing the same

The present application relates to a secondary battery and a method for manufacturing the same, and more particularly, to a secondary battery having a bending structure and a method for manufacturing the same.

As mid-to-large high-energy applications such as electric vehicles and energy storage systems (ESS) are growing rapidly beyond the existing rechargeable batteries for small devices and home appliances, the market value of the secondary battery industry is only about 22 billion dollars in 2018 However, it is expected to grow to about $118 billion by 2025. As such, in order for secondary batteries to be used as medium and large-sized energy storage media, price competitiveness, energy density, and stability that are significantly improved compared to the current level are required.

In response to these technical needs, various secondary batteries have been developed.

For example, Korean Patent Laid-Open Publication No. 10-2019-0139586 discloses a carbon nanotube and RuO ₂ deposited on the surface of the carbon nanotube, wherein the RuO2 is deposited on a defective surface of the carbon nanotube, and the RuO ₂ has a particle size of 1.0 to 4.0 nm, and the RuO2 inhibits carbon decomposition at a surface defect site of the carbon nanotube and promotes decomposition of _{Li 2} O _{2 formed on the surface of the carbon nanotube.} - An electrode for an air battery is disclosed.

One technical problem to be solved by the present application is to provide a secondary battery having a bending structure, and a method for manufacturing the same.

Another technical problem to be solved by the present application is to provide a secondary battery having a bending structure having a low manufacturing cost and a simple manufacturing process, and a manufacturing method thereof.

Another technical problem to be solved by the present application is to provide a secondary battery having a bent structure having improved charge/discharge capacity, and a method for manufacturing the same.

Another technical problem to be solved by the present application is to provide a secondary battery having a bending structure having a long lifespan and high stability, and a method for manufacturing the same.

The technical problem to be solved by the present application is not limited to the above.

In order to solve the above technical problem, the present application provides a secondary battery.

According to an embodiment, the secondary battery includes a positive electrode, a solid electrolyte, and a negative electrode, wherein the positive electrode and the solid electrolyte are provided with a laminated structure in which the laminated structure is bent, A bending region may be provided between the stacked structures, and the cathode electrode may be provided in the bending region.

According to an embodiment, the inner surface of the bending region may include the solid electrolyte, and the negative electrode may include contacting the solid electrolyte.

According to an embodiment, the stacked structure in which the positive electrode and the solid electrolyte are stacked, and the negative electrode provided in the bending region are defined as unit cells, the unit cells are provided in plurality, and the plurality of unit cells include: , and stacking the anode electrodes included in the unit cells adjacent to each other to contact each other.

According to an embodiment, the plurality of stacked unit cells is defined as a cell structure, the cell structures are provided in plurality, and the plurality of the cell structures are arranged such that the positive electrode included in the cell structure is in contact with each other. may include being

According to an embodiment, the stacked structure in which the positive electrode and the solid electrolyte are stacked, and the negative electrode provided in the bending region constitute a unit cell, the unit cells are provided in plurality, and a plurality of the unit cells Silver is stacked so that the positive electrode included in the unit cells adjacent to each other are adjacent to each other, and the secondary battery may further include a gas diffusion layer disposed between the unit cells adjacent to each other.

According to an embodiment, the plurality of stacked unit cells and the gas diffusion layer disposed between the unit cells may be defined as a cell structure, and the cell structure may include placing the anode electrodes in contact with each other. .

According to an embodiment, the stacked structure is bent to a first side and a second side opposite to the first side, and the cathode electrode is provided in a first bending region bent toward the first side, and the second side In the second bending region where the ? is bent, the anode electrodes of the stacked structure are in contact with each other and are folded.

According to an embodiment, the stacked structure is alternately and repeatedly stacked on the first side and the second side to provide a plurality of the first bending regions and a plurality of the second bending regions, and a plurality of the The cathode electrode may be provided in at least one of the first bending regions, and the anode electrodes of the stacked structure may be in contact with each other in the plurality of second bending regions.

According to an embodiment, the stacked structure in which the positive electrode and the solid electrolyte are stacked, and the plurality of the negative electrodes provided in the plurality of the first bending regions are defined as a cell structure, and the cell structure is provided in plurality , the plurality of the cell structures may include disposing the anode electrodes included in the cell structures in contact with each other.

According to an embodiment, the stacked structure is alternately and repeatedly stacked on the first side and the second side to provide a plurality of the first bending regions and a plurality of the second bending regions, and a plurality of the A plurality of the cathode electrodes may be provided in the first bending region, respectively, and a plurality of gas diffusion layers may be provided in the plurality of the second bending regions.

According to an embodiment, the stacked structure, the plurality of cathode electrodes provided in the plurality of first bending regions, and the plurality of gas diffusion layers provided in the plurality of second bending regions are defined as a cell structure, and the cell structure is provided in plurality, and the plurality of cell structures may include those disposed so that the anode electrodes included in the cell structure are in contact with each other.

According to an embodiment, the secondary battery includes a positive electrode, a solid electrolyte, and a negative electrode, wherein the positive electrode, the solid electrolyte, and the negative electrode are provided in a stacked structure stacked in sequence, the stacked structure comprises: , a first side, and a second side opposite to the first side, and in the first bending region bent toward the first side, the cathode electrode is folded in contact with each other.

According to an embodiment, the secondary battery may further include a gas diffusion layer provided in the second bending region bent toward the second side.

According to an embodiment, the positive electrode includes a compound of copper, phosphorus, and sulfur, uses oxygen as a positive electrode active material, the solid electrolyte includes bacterial cellulose, and the negative electrode includes zinc. can

According to an embodiment, the positive electrode and the solid electrolyte may include a membrane type in which a plurality of fibers constitute a network.

A secondary battery according to an embodiment of the present application includes a positive electrode, a solid electrolyte, and a negative electrode, and the positive electrode and the solid electrolyte may be in the form of a membrane in which a plurality of fibers form a network, and the negative electrode includes a plurality of can have a groove of Accordingly, the positive electrode, the solid electrolyte, and the negative electrode may have high flexibility and mechanical properties.

In the secondary battery, a stacked structure defined by stacking the positive electrode and the solid electrolyte may be bent. A bending region may be provided between the stacked structures, and the cathode electrode may be provided in the bending region.

Accordingly, both surfaces of the negative electrode may be spaced apart from the positive electrode with the solid electrolyte interposed therebetween, thereby improving charge/discharge characteristics and lifespan characteristics of the secondary battery.

1A and 1B are views for explaining a secondary battery having a bending structure according to a first embodiment of the present application.
2 is a view for explaining a secondary battery having a bending structure according to a second embodiment of the present application.
3 is a view for explaining a secondary battery having a bending structure according to a third embodiment of the present application.
4 is a view for explaining a secondary battery having a bending structure according to a fourth embodiment of the present application.
5A and 5B are views for explaining a secondary battery having a bending structure according to a fifth embodiment of the present application.
6 is a view for explaining a secondary battery having a bending structure according to a sixth embodiment of the present application.
7A and 7B are views for explaining a secondary battery having a bending structure according to a seventh embodiment of the present application.
8 is a view for explaining a secondary battery having a bending structure according to an eighth embodiment of the present application.
9A and 9B are views for explaining a secondary battery having a bending structure according to a ninth embodiment of the present application.
10 is a view for explaining a secondary battery according to an embodiment of the present application.
11 is a view for explaining a negative electrode included in a secondary battery having a bending structure and a method of manufacturing the same according to an embodiment of the present application.
12 is a view for explaining a solid electrolyte included in a secondary battery having a bending structure and a method of manufacturing the same according to an embodiment of the present application.
13 is a view for explaining a positive electrode included in a secondary battery having a bending structure according to an embodiment of the present application and a method of manufacturing the same.
14 is an SEM photograph of a cathode electrode according to Experimental Example 1-1 of the present application.
15 is a view for explaining a manufacturing process of a first composite fiber according to Experimental Example 2-2 of the present application.
16 is a view for explaining a manufacturing process of a second composite fiber according to Experimental Example 2-3 of the present application.
17 is a view for explaining a method of manufacturing a solid electrolyte according to an experimental example of the present application.
18 is a photograph of the positive electrode according to Experimental Example 3 of the present application.
19 is an SEM image of a cross-section of a secondary battery according to Experimental Example 4 of the present application.
20 is an XRD measurement result of the negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.
21 is a graph measuring a change in resistance to mechanical deformation of a negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.
22 is an XPS analysis result of the interfacial layer of the negative electrode after charging and discharging 100 times of the secondary battery including the negative electrode according to Experimental Example 1-1 of the present application.
23 is an XPS analysis result of the interfacial layer of the negative electrode after 6,000 charging and discharging of the secondary battery including the negative electrode according to Experimental Example 1-1 of the present application.
24 is an XRD analysis result of solid electrolytes according to Experimental Examples 2-4 to 2-8 of the present application.
25 is a graph illustrating ionic conductivity measurements according to temperature of solid electrolytes according to Experimental Examples 2-4 to 2-8 of the present application.
26 shows measurements of ionic conductivity according to temperature of solid electrolytes and chitosan according to Experimental Examples 2-9 to 2-13 of the present application.
27 is a measurement of the swelling ratio according to the temperature of the solid electrolyte and chitosan according to Experimental Examples 2-9 to 2-13 of the present application.
28 is an XRD graph of the positive electrode prepared according to Experimental Example 3 of the present application.
29 is a HRTEM photograph of the positive electrode according to Experimental Example 3 in the charging/discharging state of the secondary battery according to Experimental Example 4 of the present application.
30 is a graph evaluating ORR, OER, and HER characteristics according to a composition ratio of P and S of the positive electrode according to Experimental Example 3 of the present application.
31 is a graph evaluating OER, ORR, and HER characteristics according to a crystal plane in the positive electrode according to Experimental Example 3 of the present application.
32 is a graph for explaining charge/discharge characteristics in a bending state of a secondary battery according to Experimental Example 4 of the present application.
33 is a graph for explaining a change in capacity and efficiency according to the number of times of charging and discharging in a bending state of the secondary battery according to Experimental Example 4 of the present application.
34 is a graph evaluating long-term stability in a bending state of a secondary battery according to Experimental Example 4 of the present application.
35 is a graph for comparing charge/discharge characteristics of a secondary battery in a bending state with other batteries according to Experimental Example 4 of the present application.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In addition, in various embodiments of the present specification, terms such as first, second, third, etc. are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another. Accordingly, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes a complementary embodiment thereof. In addition, in the present specification, 'and/or' is used to mean including at least one of the elements listed before and after.

In the specification, the singular expression includes the plural expression unless the context clearly dictates otherwise. In addition, terms such as "comprise" or "have" are intended to designate that a feature, number, step, element, or a combination thereof described in the specification is present, and one or more other features, numbers, steps, configuration It should not be construed as excluding the possibility of the presence or addition of elements or combinations thereof. Also, in the present specification, the term “connection” is used to include both indirectly connecting a plurality of components and directly connecting a plurality of components.

In addition, in the following description of the present invention, if it is determined that a detailed description of a related well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

1A and 1B are views for explaining a secondary battery having a bending structure according to a first embodiment of the present application.

1A and 1B , the rechargeable battery having a bending structure according to the first embodiment may include a positive electrode 300 , a solid electrolyte 200 , and a negative electrode 100 .

The positive electrode 300 and the solid electrolyte 200 may be stacked to define a stacked structure.

The stacked structure including the positive electrode 300 and the solid electrolyte 200 may be bent, so that a bending region may be provided between the stacked structures. 1A and 1B , the inner surface of the bending region may be formed of the solid electrolyte 200 .

The negative electrode 100 may be provided in the bending region formed of the solid electrolyte 200 . In other words, the negative electrode 100 may be provided in a sandwiched form in the stacked structure, and the negative electrode 100 may be in contact with the solid electrolyte 200 . That is, the negative electrode 100 may be spaced apart from the positive electrode 300 with the solid electrolyte 200 interposed therebetween. Both the first surface of the negative electrode 100 and the second surface opposite to the first surface may be spaced apart from the positive electrode 300 with the solid electrolyte 200 interposed therebetween.

The positive electrode 300 , the stacked structure in which the solid electrolyte 200 is stacked, and the negative electrode 100 provided in the bending region may be defined as a unit cell.

A plurality of the unit cells may be provided as shown in FIG. 1A , and a plurality of the unit cells may be stacked. The stacked unit cells may be defined as one cell structure. In this case, the plurality of unit cells may be stacked so that the anode electrodes 300 included in the unit cells adjacent to each other contact each other.

Accordingly, the positive electrode 300 included in the different unit cells may be electrically connected to each other, and the negative electrode 100 included in the different unit cells may be spaced apart from each other.

A lead wire may be provided on one open side of the plurality of cathode electrodes 100 spaced apart from each other, so that the plurality of cathode electrodes 100 spaced apart from each other may be electrically connected.

According to the embodiment of the present application, as described above, the negative electrode 100 may be inserted into the bending region of the stacked structure including the positive electrode 300 and the solid electrolyte 200 . Accordingly, the solid electrolyte 200 between the first surface of the negative electrode 100 and the positive electrode 300 and between the second surface of the negative electrode 100 and the positive electrode 300 . ) can be provided. For this reason, in the charging/discharging process of the secondary battery, between the first surface of the negative electrode 100 and the positive electrode 300 , and the second surface of the negative electrode 100 and the positive electrode ( 300), ions (eg, OH ⁻ ) may move, and as a result, the charge/discharge capacity of the secondary battery may be improved.

2 is a view for explaining a secondary battery having a bending structure according to a second embodiment of the present application.

Referring to FIG. 2 , a plurality of the cell structures according to the first embodiment described with reference to FIGS. 1A and 1B are provided.

The cell structures provided in plurality may be disposed to face each other. Specifically, a plurality of the cell structures may be disposed so that the anode electrodes 300 included in the cell structure contact each other as shown in FIG. 2 .

Accordingly, the anode electrodes 300 included in the different unit cells as well as the anode electrodes 300 included in the different cell structures may be electrically connected without performing an additional process.

As described above, the different cell structures may be disposed such that the positive electrode 300 is in contact with each other, thereby improving the energy density of the secondary battery.

3 is a view for explaining a secondary battery having a bending structure according to a third embodiment of the present application.

Referring to FIG. 3 , the cell structure according to the first embodiment described with reference to FIGS. 1A and 1B is provided, and a gas diffusion layer 50 may be provided between the unit cells. Specifically, the plurality of unit cells are stacked such that the anode electrodes 300 included in the unit cells adjacent to each other are adjacent to each other, and the gas diffusion layer 50 is provided between the anode electrodes 300 adjacent to each other. can

The unit cells may be provided in plurality as shown in FIG. 3 , and a plurality of the unit cells may be stacked. The stacked unit cells and the gas diffusion layer 50 between the unit cells may be defined as one cell structure.

Oxygen can be easily and smoothly supplied to the positive electrode 300 of the secondary battery having a bending structure according to an embodiment of the present application using oxygen as a positive electrode active material by the gas diffusion layer 50 , thereby , the charging and discharging characteristics of the secondary battery may be improved.

4 is a view for explaining a secondary battery having a bending structure according to a fourth embodiment of the present application.

Referring to FIG. 4 , a plurality of the cell structures according to the third embodiment described with reference to FIG. 3 are provided.

The cell structures provided in plurality may be disposed to face each other. Specifically, a plurality of the cell structures may be disposed such that the positive electrode 300 included in the cell structure is in contact with each other as shown in FIG. 4 .

Accordingly, the anode electrodes 300 included in the different unit cells as well as the anode electrodes 300 included in the different cell structures may be electrically connected without performing an additional process.

As described above, the different cell structures may be disposed such that the positive electrode 300 is in contact with each other, thereby improving the energy density of the secondary battery.

5A and 5B are views for explaining a secondary battery having a bending structure according to a fifth embodiment of the present application.

5A and 5B , a secondary battery having a bending structure according to the fifth embodiment includes a positive electrode 300 , a solid electrolyte 200 , and a negative electrode 100 , and the positive electrode 300 . and the solid electrolyte 200 may be stacked to define a stacked structure.

The stacked structure may be bent toward a first side and a second side opposite to the first side. Accordingly, a first bending region 11 in which the laminate structure is bent toward the first side may be provided, and a second bending region 12 in which the laminate structure is bent toward the second side may be provided.

The cathode electrode 100 may be provided in the first bending region 11 . As shown in FIG. 5B , the first bending area 11 may be opened toward the first side, and the cathode electrode 100 may be provided in the opened first bending area 11 .

In the second bending region 12 , the positive electrode 300 of the stacked structure may be in contact with each other to be folded. In other words, nothing is provided in the second bending region 12 , and the positive electrode 300 may be in contact with each other by being folded as it is.

The stacked structure may be alternately and repeatedly bent to the first side and the second side to provide a plurality of the first bending regions 11 and a plurality of the second bending regions 12 . The cathode electrode 100 is provided in at least one of the plurality of first bending regions 11 , and the positive electrode 300 of the stacked structure is in contact with each other in the plurality of second bending regions 12 . can

The negative electrode 100 may be provided in a sandwiched form in the laminate structure, and the positive electrode 300 and the solid electrolyte 200 included in the laminate structure may be continuously provided.

The stacked structure in which the positive electrode 300 and the solid electrolyte 200 are stacked, and the plurality of negative electrodes 100 provided in the plurality of first bending regions 11 may be defined as a cell structure.

According to an embodiment of the present application, the anode electrode 300 and the solid electrolyte 200 are stacked by bending the stacked structure to the first side and the second side to form the cathode in the first bending region 11 . The electrode 100 may be inserted. Accordingly, the secondary battery may be manufactured by a simple process of bending the stacked structure and inserting the negative electrode 100 , and the secondary battery may be manufactured in a continuous process, thereby facilitating mass production.

In addition, as will be described later in Experimental Example 4, the compound of Cu, P, and S included in the positive electrode 300 may be coated on a metal mesh, and external air and/or oxygen may be supplied to the positive electrode by the metal mesh. It can be easily supplied to the electrode 300 . Accordingly, the secondary battery having a bending structure according to the fifth embodiment of the present application may be implemented in a state in which the gas diffusion layer is omitted.

However, it means that in the secondary battery of the bending structure according to the fifth embodiment of the present application, the gas diffusion layer may be omitted, and the technical idea according to the embodiment of the present application is except for the case in which the gas diffusion layer is included. It is clear that it is not

6 is a view for explaining a secondary battery having a bending structure according to a sixth embodiment of the present application.

Referring to FIG. 6 , a plurality of the cell structures according to the fifth embodiment described with reference to FIGS. 5A and 5B are provided.

The cell structures provided in plurality may be disposed to face each other. Specifically, a plurality of the cell structures may be disposed such that the anode electrodes 300 included in the cell structure are in contact with each other as shown in FIG. 6 .

Accordingly, the anode electrodes 300 included in the different unit cells as well as the anode electrodes 300 included in the different cell structures may be electrically connected without performing an additional process.

7A and 7B are views for explaining a secondary battery having a bending structure according to a seventh embodiment of the present application.

7A and 7B , the cell structure according to the fifth embodiment described with reference to FIGS. 5A and 5B is provided, and a gas diffusion layer 50 may be provided in the second bending region 12 . . Specifically, unlike described with reference to FIGS. 5A and 5B , the gas diffusion layer 50 may be provided in the second bending region 12 in which the laminated structure is bent to the second side, thereby, As illustrated in FIG. 7A , the anode electrode 300 may not contact in the second bending region 12 .

Oxygen can be easily and smoothly supplied to the positive electrode 300 of the secondary battery having a bending structure according to an embodiment of the present application using oxygen as a positive electrode active material by the gas diffusion layer 50 , thereby , the charging and discharging characteristics of the secondary battery may be improved.

8 is a view for explaining a secondary battery having a bending structure according to an eighth embodiment of the present application.

Referring to FIG. 8 , a plurality of the cell structures according to the seventh embodiment described with reference to FIGS. 7A and 7B are provided.

The cell structures provided in plurality may be disposed to face each other. Specifically, a plurality of the cell structures may be arranged such that the anode electrodes 300 included in the cell structure are in contact with each other as shown in FIG. 8 .

Accordingly, the energy density of the secondary battery may be improved.

9A and 9B are views for explaining a secondary battery having a bending structure according to a ninth embodiment of the present application.

9A and 9B , a secondary battery having a bending structure according to the ninth embodiment of the present application may include a positive electrode 300 , a solid electrolyte 200 , and a negative electrode 100 . The secondary battery may further include a gas diffusion layer 50 .

the anode electrode (300). The solid electrolyte 200 and the negative electrode 100 may be sequentially stacked to define a stacked structure.

The stacked structure may be bent toward a first side and a second side opposite to the first side, as described with reference to FIGS. 5A and 5B . Accordingly, a first bending region 11 in which the laminate structure is bent toward the first side may be provided, and a second bending region 12 in which the laminate structure is bent toward the second side may be provided.

In the first bending region 11 , the cathode electrodes 100 of the stacked structure may be folded to contact each other. In other words, nothing is provided in the first bending region 11 , and the cathode electrode 100 may be in contact with each other by being folded as it is.

The gas diffusion layer 50 may be provided in the second bending region 12 . As illustrated in FIG. 9B , the second bending region 12 may be opened toward the second side, and the gas diffusion layer 50 may be provided in the opened second bending region 12 .

The stacked structure may be alternately and repeatedly bent to the first side and the second side to provide a plurality of the first bending regions 11 and a plurality of the second bending regions 12 . The cathode electrodes 100 of the stacked structure may contact each other in the plurality of first bending regions 11 , and the gas diffusion layer 50 may be disposed in at least one of the plurality of second bending regions 12 . may be provided.

The positive electrode 300, the solid electrolyte 200, and the negative electrode 100 included in the stacked structure may be continuously provided, and the positive electrode 300, the solid electrolyte 200, and The stacked structure in which the cathode electrode 100 is stacked and the gas diffusion layer 50 provided in the plurality of second bending regions 12 may be defined as a cell structure.

According to the embodiment of the present application, the stacked structure in which the positive electrode 300 , the solid electrolyte 200 , and the negative electrode 100 are stacked is bent toward the first side and the second side to form the second The gas diffusion layer 50 may be inserted into the bending region 12 . Accordingly, the secondary battery can be manufactured by a simple process of bending the stacked structure and inserting the gas diffusion layer 50, and the secondary battery is manufactured by a continuous roll-to-roll process, making mass production easier can

10 is a view for explaining a secondary battery according to an embodiment of the present application.

Referring to FIG. 10 , as described in the first to ninth embodiments of the present application described above, the positive electrode 300 , the solid electrolyte 200 , and the negative electrode 100 and the current collector 400 . ), the secondary battery according to the embodiment of the present application including, may have a bent structure.

Accordingly, the positive electrode 300 , the solid electrolyte 200 , and the negative electrode 100 may be formed of a highly flexible material and process. Hereinafter, the negative electrode 100 , the solid electrolyte 200 , and the positive electrode 300 will be sequentially described.

11 is a view for explaining a negative electrode included in a secondary battery having a bending structure and a method of manufacturing the same according to an embodiment of the present application.

Referring to FIG. 11 , a flat base metal substrate 10 is prepared. The base metal substrate 10 includes a first surface and a second surface opposite to the first surface, and both the first surface and the second surface may be flat. According to an embodiment, the base metal substrate 10 may include zinc.

A plurality of beads 110 may be disposed on the base metal substrate 10 . The plurality of beads 110 may be mixed with a solvent and then spin-coated on the base metal substrate 10 . The plurality of beads 110 may be disposed to be spaced apart from each other on the base metal substrate 10 . The plurality of beads 110 may be disposed on the first surface of the base metal substrate 10 . For example, the plurality of beads 110 may be polystyrene beads.

Before disposing the plurality of beads 110 on the base metal substrate 10 , the base metal substrate may be treated with HCl and washed. Accordingly, the native oxide film on the base metal substrate 10 may be removed.

In addition, before disposing the plurality of beads 110 on the base metal substrate 10 , the first surface of the base metal substrate 10 may be hydrophilic treated. For example, by treating the first surface of the base metal substrate 10 using a pirana solution, the first surface of the base metal substrate 10 may have a hydrophilic property. Accordingly, the plurality of beads 110 may be stably and easily provided on the first surface of the base metal substrate 10 .

The size of the plurality of beads 110 may be reduced. For example, by applying an oxygen plasma on the base metal substrate 10 having the plurality of beads 110 , regions adjacent to the surfaces of the plurality of beads 110 may be removed, and thereby, the plurality of beads 110 . The size of the bead 110 may be reduced. As the size of the plurality of beads 110 is reduced, a distance between the plurality of beads 110 may increase.

A mask layer 120 may be formed on the base metal substrate 10 on which the plurality of beads 110 having reduced sizes are disposed. The mask layer 120 may be formed of a polymer using a spin coating process, and thus may cover the base metal substrate 10 exposed between the plurality of beads 110 . In addition, in the mask layer 120 , the plurality of beads 110 and the base metal substrate 10 may not be provided on a bonding surface.

By removing the plurality of beads 110 , an etch target region 122 of the base metal substrate 10 that is not covered with the mask layer 120 may be exposed. As described above, the mask film 120 may not be provided on the bonding surface of the plurality of beads 110 and the base metal substrate 10 , and thus the plurality of beads 110 may be removed. After being in contact with the plurality of beads 110 and the base metal substrate 10, the etch target region 122 (the bonding surface) may be exposed.

After the etch target region 122 is exposed, the exposed etch target region 122 of the base metal substrate 10 is etched using the mask layer 120 as a mask to form a cathode electrode 100 . This can be manufactured.

By using the mask layer 120 as a mask, the etching target region 122 may be etched to provide a plurality of grooves 124 in the cathode electrode 100 . The plurality of grooves 124 may correspond to the etch target region 122 . The plurality of grooves 124 may not pass through the cathode electrode 100 . In other words, the plurality of grooves 124 may have a bottom surface and a side surface, and may have an open top surface.

The etching target region 122 may be etched using an etching gas. According to an embodiment, the etching gas may include fluorine and sulfur. For example, the etching gas may include _{SF 6 .}

According to an embodiment, a portion of the element included in the etching gas may remain on the bottom surface and/or the side surface of the plurality of grooves 124 . Due to this, the characteristics of the negative electrode 100 to be described later manufactured from the base metal substrate 10 may be improved. Specifically, in the charging/discharging process of the secondary battery including the negative electrode 100 , an interface layer may be formed on the surface (the first surface) of the negative electrode 100 in contact with the electrolyte. In this case, generation of the interface layer may be induced by the elements included in the etching gas remaining on the bottom surface and/or the side surfaces of the plurality of grooves 124 , and thus the interface layer is stable. By and easily generated, the charge/discharge characteristics and lifespan characteristics of the secondary battery may be improved.

According to an embodiment, diameters and depths of the plurality of grooves 124 may be controlled. Specifically, the diameters of the plurality of grooves 124 may be adjusted by a method of controlling the diameters of the plurality of beads 110 , and the diameters of the plurality of beads 110 may be adjusted on the base metal substrate 10 . It can be controlled by a method of adjusting the initial size of the plurality of beads 110 to be coated or the degree of reduction in the size of the plurality of beads 110 . The depths of the plurality of grooves 124 may be adjusted according to process conditions (eg, time, concentration, pressure, power, etc.) for providing the etching gas.

According to an embodiment, a crystal plane developed in the cathode electrode 100 may be controlled according to diameters and depths of the plurality of grooves 124 . Specifically, as the depth of the plurality of grooves 124 increases from 100 nm to 500 nm, (100) crystal planes and (101) crystal planes may be further developed, (002) crystal planes, (102) crystal planes, (103) The crystal plane, and the (110) crystal plane may be less developed, and the (100) crystal plane and the (101) crystal plane may be less developed as the depth increases from 500 nm to 5 μm. In addition, as the diameter of the plurality of grooves 124 increases from 100 nm to 500 nm, the (100) crystal plane and the (101) crystal plane develop more, and as the diameter of the plurality of grooves 124 increases from 500 nm to 1 μm, the (100) crystal plane and the (101) crystal plane become may be less developed.

Whether or not the crystal plane of the cathode electrode 100 is developed may be confirmed through XRD analysis. As described above, when the diameter and depth of the plurality of grooves 124 increase from 100 nm to 500 nm, the ratio of the peak value corresponding to the (101) crystal plane to the peak value corresponding to the (002) crystal plane ((101) /(002)) increases, and when the diameter and depth of the plurality of grooves 124 exceed 500 nm, the ratio of the peak value corresponding to the (101) crystal plane to the peak value corresponding to the (002) crystal plane ((101) )/(002)) may decrease.

According to an embodiment, according to the ratio ((101)/(002)) of the peak value corresponding to the (002) crystal plane to the peak value corresponding to the (101) crystal plane, the electrochemical properties of the cathode electrode 100 are can be controlled. Specifically, as the ratio of the peak value corresponding to the (101) crystal plane to the peak value corresponding to the (002) crystal plane ((101)/(002)) is higher, the over of the secondary battery including the negative electrode 100 is The potential value may be reduced.

Accordingly, the diameter and depth of the plurality of grooves 124 so that the ratio of the ratio (101)/(002)) of the peak value corresponding to the (101) crystal plane to the peak value corresponding to the (002) crystal plane is increased. can be controlled, thereby improving the electrochemical properties of the cathode electrode 100 . For example, the diameter and depth of the plurality of grooves 124 may be 500 nm.

Also, according to an embodiment, the lattice constant of the unit cell of the cathode electrode 100 may be controlled according to the diameter and depth of the plurality of grooves 124 . Specifically, when the cathode electrode 100 has a hexagonal crystal structure, as the diameters and depths of the plurality of grooves 124 increase, the a-axis lattice constant of the unit cell of the cathode electrode 100 increases. , and the c-axis lattice constant may decrease.

The cathode electrode 100 according to the embodiment of the present application is formed after the plurality of beads 110 and the mask layer 120 are sequentially formed on the base metal substrate 10 , and then the plurality of beads 110 . ) and etching the base metal substrate 10 using the mask layer 120 as a mask.

Accordingly, the cathode electrode 100 having the plurality of grooves 124 may be manufactured in a simple method with a high yield, and may have high flexibility and mechanical properties due to the plurality of grooves 124 .

12 is a view for explaining a solid electrolyte included in a secondary battery having a bending structure and a method of manufacturing the same according to an embodiment of the present application.

Referring to FIG. 12 , a chitosan derivative is prepared. The chitosan derivative may be a mixture of a chitosan precursor in a solvent. According to one embodiment, the chitosan derivative, chitosan chloride and a solvent, may be a solubilizing agent added. Accordingly, the chitosan chloride can be easily dissolved in a solvent, and the chitosan derivative can be easily provided in a medium to be described later, so that cellulose to which chitosan is bound can be easily prepared.

For example, the solvent may be aqueous acetic acid, and the solvent is glycidyltrimethylammonium chloride, (2-Aminoethyl)trimethylammonium chloride, (2-Chloroethyl)trimethylammonium chloride, (3-Carboxypropyl)trimethylammonium chloride, or (Formylmethyl)trimethylammonium chloride It may include at least one of them.

The chitosan has excellent thermal and chemical stability, has high ionic conductivity, and can contain OH ions without loss for a long period of time. In addition, when used in the secondary battery, it may have high compatibility with the negative electrode 100 and the positive electrode 300 .

From the chitosan derivative, chitosan bound to cellulose is produced. The step of producing the cellulose to which the chitosan is bound is a step of preparing a culture medium having the chitosan derivative, and injecting and culturing a bacterial strain in the culture medium, the cellulose 212 to which chitosan 214 is bound It may include the step of producing a base composite fiber 210 including. In this case, the cellulose 212 may be bacterial cellulose.

According to an embodiment, the cellulose 212 to which the chitosan 214 is bound may be prepared by culturing the bacterial pellicle in the culture medium and desalting the bacterial pellicle. The bacterial pellicle prepares a culture medium containing the chitosan derivative together with raw materials for yeast and bacterial culture (eg, pineapple juice, peptone, disodium phosphate, citric acid), and after injecting the strain, culture can be manufactured. For example, the strain may be Acetobacter Xylinum.

After washing and drying the cultured bacterial pellicle, desalting with an acidic solution (eg, HCl), neutralizing and removing the solvent. The base complex comprising the cellulose 212 to which the chitosan 214 is bound. Fibers 210 may be fabricated. In the desalting process, the remaining Na, K, or cell shielding and debris are removed, so that the cellulose 212 to which the chitosan 214 of high purity is bound can be prepared.

In addition, the chitosan 214 may be chemically bonded to the cellulose 212 . Accordingly, in the cellulose 212 to which the chitosan 214 is bound, stretching vibration corresponding to C-N may be observed during XPS analysis.

According to an embodiment, the surface of the cellulose 212 to which the chitosan 214 is bonded using an oxidizing agent, that is, the surface of the base composite fiber 210 is oxidized, so that the first composite fiber 210a is manufactured. can

Specifically, the step of preparing the first composite fiber 210a includes adding the base composite fiber 210 to an aqueous solution containing an oxidizing agent to prepare a source solution, adjusting the pH of the source solution to basic Step, adjusting the pH of the source solution to neutral, and washing and drying the pulp in the source solution may include preparing the first composite fiber (210a).

For example, the aqueous solution containing the oxidizing agent may be a TEMPO aqueous solution. Or, for another example, the aqueous solution containing the oxidizing agent is 4-Hydroxy-TEMPO, (Diacetoxyiodo)benzene, 4-Amino-TEMPO, 4-Carboxy-TEMPO, 4-Methoxy-TEMPO, TEMPO methacrylate, 4-Acetamido It may include at least one of -TEMPO, 3-Carboxy-PROXYL, 4-Maleimido-TEMPO, 4-Hydroxy-TEMPO benzoate, or 4-Phosphonooxy-TEMPO.

The source solution may further include a sacrificial reagent and an additional oxidizing agent for the oxidation reaction of the base composite fiber 210 . For example, the sacrificial reagent may include at least one of NaBr, sodium iodide, sodium bromate, sodium bromite, sodium borate, sodium chlorite, or sodium chloride, and the additional oxidizing agent is, NaClO, potassium hypochlorite, Lithium at least one of hypochlorite, sodium chlorite, sodium chlorate, Perchloric acid, Potassium perchlorate, Lithium perchlorate, Tetrabutylammonium perchlorate, Zinc perchlorate, hydrogen peroxide, or sodium peroxide.

According to an embodiment, in the step of adjusting the pH of the source solution to be basic, the pH of the source solution may be adjusted to 10. Accordingly, the oxidation reaction can be easily induced while minimizing the precipitate, and the oxidation degree of the first composite fiber 210a can be improved as compared to the reaction condition of pH 8 to 9.

According to an embodiment, after the base composite fiber 210 and the sacrificial reagent are provided in an aqueous solution containing the oxidizing agent, the additional oxidizing agent may be provided. In addition, the additional oxidizing agent may be provided in drops. Accordingly, the rapid oxidation of the base composite fiber 210 may be prevented, and as a result, the surface of the base composite fiber 210 may be uniformly and stably oxidized.

In addition, according to an embodiment, by binding bromine to the surface of the cellulose 212 to which the chitosan 214 is bonded and replacing the first functional group 216 containing nitrogen with bromine, the second composite fiber ( 210b) can be prepared.

The first functional group 216 may be represented by the following <Formula 1>, and the first functional group 216 may be combined with the chitosan 214 and/or the cellulose 212 . .

<Formula 1>

That is, the second composite fiber 210b may have a quaternary N.

Specifically, the step of preparing the second composite fiber 210b includes dispersing the base composite fiber 210 in a first solvent and adding a bromine source to prepare a first source solution, the first source solution adding a coupling agent to and reacting to prepare a reaction suspension; filtering, washing and freeze-drying the reaction suspension to prepare a brominated base composite fiber; dispersing the brominated base composite fiber in a second solvent to prepare a reaction suspension 2 Preparing a source solution, adding and reacting the precursor of the first functional group 216 to the second source solution, filtering, washing, and freeze-drying the reacted solution to obtain the second composite fiber 210b It may include the step of manufacturing.

For example, the first solvent and the second solvent may be the same as each other, and may include at least one of N, N-dimethylacetamide, Acetamide, Acetonitrile, ethanol, ethylenediamine, diethyl ether, or benzaldehyde.

For example, the bromine source may include at least one of LiBr, sodium bromide, and potassium bromide.

For example, the coupling agent may include N-bromosuccinimide and triphenylphosphine. Bromine may be easily coupled to the surface of the base composite fiber 210 by the coupling agent. Specifically, bromine in N-bromosuccinimide may be combined with the base composite fiber 210 , and triphenylphosphine may reduce a bromine precursor (bromosuccinimide or N-bromosuccinimide) to improve the reaction rate.

As described above, after obtaining the brominated base composite fiber in the reaction suspension, the brominated base composite fiber may be freeze-dried. Accordingly, loss of bromine in the brominated base composite fiber may be minimized, and secondary reaction of bromine with other elements may be minimized.

For example, the precursor of the first functional group 216 may include 1,4-Diazabicyclo[2.2.2]octane.

The solid electrolyte 200 may be manufactured using the cellulose 212 to which the chitosan 214 is bound.

The solid electrolyte 200 may be manufactured in the form of a membrane in which the base composite fiber 210 including the cellulose 212 to which the chitosan 214 is bonded constitutes a network. For this reason, the solid electrolyte 200 may be provided with a plurality of pores therein, may have a high surface area, and may have excellent flexibility and mechanical properties.

The solid electrolyte 200 may be in a state in which a crystalline phase and an amorphous phase are mixed. More specifically, in the solid electrolyte 200 , the ratio of the amorphous phase may be higher than the ratio of the crystalline phase. Accordingly, the solid electrolyte 200 may have high ion mobility.

According to an embodiment, the solid electrolyte 200 may be manufactured by a gelatin process using the first composite fiber 210a and the second composite fiber 210b. In this case, the solid electrolyte 200 includes the first composite fiber 210a and the second composite fiber 210b, wherein the first composite fiber 210a and the second composite fiber 210b are can be cross-linked to each other. By the first composite fiber 210a, the number of OH ions in the solid electrolyte 200 may increase, ion conductivity may be improved, negative charge density may be increased, and swelling resistance may be improved. In addition, by the second composite fiber 210b, the molecular weight is increased to improve thermal stability, and ion exchange capacity is improved to have a high water impregnation rate and high swelling resistance, and the first Crosslinking strength with the composite fiber 210a may be improved, and it may have high solubility (ion discerning selectivity) selectively in a specific solvent. Accordingly, the charging/discharging characteristics and lifespan characteristics of the secondary battery including the solid electrolyte 200 may be improved.

Specifically, preparing the solid electrolyte 200 includes preparing a mixed solution by mixing the first conjugated fibers 210a and the second conjugated fibers 210b with a solvent, adding a crosslinking agent to the mixed solution, and It may include adding and reacting an initiator to prepare a suspension, casting the suspension on a substrate and drying to prepare a composite fiber membrane, and performing an ion exchange process on the composite fiber membrane.

For example, the solvent may include a mixed solvent of methylene chloride, 1,2-Propanediol, and acetone, the crosslinking agent may include glutaraldehyde, and the initiator may include N,N-Diethyl-N-methyl -N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide may be included.

Also, for example, the ion exchange process for the composite fiber membrane may include providing an aqueous KOH solution and an aqueous ZnTFSI solution to the composite fiber membrane. Due to this, the OH ion content in the solid electrolyte may be improved.

As described above, according to the embodiment of the present application, the solid electrolyte 200 is at least one of the base composite fiber 210, the first composite fiber 210a, or the second composite fiber 210b. It may include a membrane comprising one.

In the solid electrolyte 200, the ratio of the chitosan 214 can be easily controlled according to the content of the chitosan derivative provided in the culture medium. According to the ratio of the chitosan 214 , the crystallinity, ionic conductivity, and swelling ratio of the solid electrolyte 200 may be controlled. Specifically, as the ratio of the chitosan 214 increases, the crystallinity of the solid electrolyte may gradually decrease.

According to one embodiment, the content of the chitosan 214 may be more than 30wt% and less than 70wt%. If the content of the chitosan 214 is 30 wt% or less, or 70 wt% or more, the ionic conductivity of the solid electrolyte is significantly reduced, and the swelling ratio may be significantly increased.

However, according to the embodiment of the present application, the proportion of the chitosan 214 in the solid electrolyte 200 may be more than 30 wt% and less than 70 wt%, and therefore, the solid electrolyte 200 has high ionic conductivity characteristics. While maintaining it, it can have a low swelling ratio value.

13 is a view for explaining a positive electrode included in a secondary battery having a bending structure according to an embodiment of the present application and a method of manufacturing the same.

Referring to FIG. 13 , a first precursor having a chalcogen element, a second precursor having phosphorus, and a third precursor having a transition metal may be prepared.

According to one embodiment, the chalcogen element may include sulfur. In this case, for example, the first precursor is dithiooxamide, Dithiobiuret, Dithiouracil, Acetylthiourea, Thiourea, N-methylthiourea, Bis(phenylthio)methane, 2-Imino-4-thiobiuret, N,N′, Ammonium sulfide, Methyl It may include at least one of methanesulfonate, sulfur powder, sulphates, N,N-Dimethylthioformamide, or Davy Reagent methyl.

Alternatively, according to another embodiment, the chalcogen element may include at least one of oxygen, selenium, or tellurium.

For example, the second precursor is tetradecylphosphonic acid, ifosfamide, Octadecylphosphonic acid, Hexylphosphonic acid, Trioctylphosphine, Phosphoric acid, Triphenylphosphine, Ammonium Phosphide, pyrophosphates, Davy Reagent methyl, Cyclophosphamide monohydrate, Phosphorus (V methyl, Cyclophosphamide) triphosphoryl, Phosphorus. It may include at least one of chloride, Phosphorus pentachloride, or Phosphorus pentasulfide.

According to an embodiment, different heterogeneous species including phosphorus may be used as the second precursor. For example, as the second precursor, a mixture of tetradecylphosphonic acid and ifosfamide 1:1 (M%) may be used. Accordingly, the stoichiometric ratio of the transition metal, phosphorus, and the chalcogen element can be controlled to 1:1:1. As a result, the positive electrode 300 according to the embodiment of the present application may have a covelite structure, and the electrochemical properties of the positive electrode 300 may be improved.

According to an embodiment, the transition metal may include copper. In this case, for example, the third precursor is copper chloride, copper(II) sulfate, copper(II) nitrate, copper selenide, copper oxychloride, cupric acetate, copper carbonate, copper thiocyanate, copper sulfide, copper hydroxide, copper It may include at least one of naphthenate, or copper(II) phosphate.

Alternatively, according to another embodiment, the transition metal may include at least one of magnesium, manganese, cobalt, iron, nickel, titanium, zinc, aluminum, and tin.

A mixture may be prepared by mixing the first precursor, the second precursor, and the third precursor, and adding a first reducing agent.

After the first precursor, the second precursor, and the third precursor are mixed in a solvent, the first reducing agent may be added. For example, the solvent may be a mixture of ethanol and ethylenediamine. Alternatively, as another example, the solvent may be a mixture of ethanol and toluene.

According to an embodiment, the direction of the crystal plane of the positive electrode 300, which will be described later, may be controlled according to the type and mixing ratio of the solvent. In other words, depending on the type and mixing ratio of the solvent, the development of the (101) crystal plane in the positive electrode 300 may be controlled, and thus, the electrochemical properties of the positive electrode 300 may be controlled. have.

According to an embodiment of the present application, the solvent may be selected so that a (101) crystal plane is developed in the positive electrode 300 in the same way as the (101) crystal plane is developed in the negative electrode 100 to be described later. (eg, mixing ethanol and ethylenediamine in a 1:3 volume ratio), thereby improving the electrochemical properties (eg, ORR, OER, HER) of the positive electrode 300 .

After the first precursor, the second precursor, and the third precursor are mixed in the solvent, nucleation and crystallization may proceed as shown in FIG. 13A .

For example, the first reducing agent may include at least one of Ammonium hydroxide, Ammonium chloride, and Tetramethylammonium hydroxide.

An intermediate product including a plurality of stems may be prepared by co-precipitating the mixture including the first precursor, the second precursor, the third precursor, the first reducing agent, and the solvent.

The mixture may be heat treated to form an intermediate product, as shown in FIG. 13(b) . The intermediate product may have a plurality of stems, and the plurality of stems may constitute a network with each other.

For example, the mixture to which the first reducing agent is added may be reflux heat treated at 120° C., and then washed with deionized water and ethanol.

The first reducing agent may perform the function of the reducing agent while heat-treating, maintain pH and increase the reaction rate. Accordingly, the intermediate product having the plurality of stems can be easily prepared. For example, when the transition metal is copper and the chalcogen element is sulfur, the intermediate structure may be CuPS having a cobelite crystal structure.

In a method of adding a second reducing agent to the intermediate product and heat-treating under pressure, a plurality of fibrillated fibers including the transition metal, the chalcogen element, and phosphorus are obtained by branching a plurality of branches from the plurality of stems. can be manufactured.

According to an embodiment, after the intermediate product and the second reducing agent are added to deionized water, a pressure heat treatment process may be performed.

For example, the second reducing agent is, Triton X-165, Triton X-102, Triton X-45, Triton X-114 Triton X-405, Triton X-101, Trimesic acid, Diamide, Peroxynitrite, formaldehyde, Thimerosal, Or it may include at least one of chloramine-T.

According to an embodiment, together with the second reducing agent, a chalcogen element source including the chalcogen element may be further added. Due to this, the chalcogen element lost in the reaction process is supplemented by the chalcogen element source, the electrode structure of a sponge structure in which a plurality of fibrillated fibers to be described later constitute a network can be easily formed .

For example, when the chalcogen element is sulfur, the chalcogen element source may include at least one of sodium bisulfite, sodium sulfate, sodium sulfide, sodium thiosulfate, sodium thiomethoxide, sodium ethanethiolate, or sodium methanethiolate.

The process of mixing the intermediate product and the second reducing agent in deionized water may be performed in a cooled state. The reaction rate may be prevented from being excessively increased due to heat generated in the process of adding the second reducing agent, and thus, the electrochemical properties of the positive electrode 300 may be improved.

As described above, by adding a second reducing agent to the intermediate product and heat-treating it under pressure, as shown in FIG. 13(c) , a plurality of branches may be branched from the plurality of stems, and thereby, fibrils The positive electrode 300 having a sponge structure in which a plurality of fibers is formed may be formed.

The anode electrode 300 having a sponge structure may be immersed in liquid nitrogen after being washed with deionized water and ethanol. Due to this, mechanical properties and flexibility of the positive electrode 300 having a sponge structure may be improved.

In addition, after being immersed in liquid nitrogen, the anode electrode 300 having a sponge structure is freeze-dried to remove residual solvents, thereby minimizing a secondary reaction.

As described above, the positive electrode 300 may include a membrane having a sponge structure in which the plurality of fibrillated fibers in which the plurality of branches are branched from the plurality of stems constitute a network. For this reason, the anode electrode 300 may have a porous structure in which a plurality of pores having a size of 1 to 2 nm are provided, and may be flexible.

The positive electrode 300 may be used as a positive electrode of a metal-air battery together with the negative electrode 100 and the solid electrolyte 200 , and oxygen may be used as a positive electrode active material.

In addition, as described above, the type and ratio of the solvent mixed with the first precursor, the second precursor, and the third precursor are controlled so that a (101) crystal plane is developed in the anode electrode 300 . can Accordingly, in the XRD analysis of the positive electrode 300 , a peak value corresponding to a (101) crystal plane may have a maximum value compared with a peak value corresponding to another crystal plane. In XRD measurement, the peak value corresponding to the (101) crystal plane can be observed in the range of the 2θ value of 19° to 21°.

The plurality of fibers constituting the anode electrode 300 may include a compound of the transition metal, phosphorus, and the chalcogen element. For example, when the transition metal is copper and the chalcogen element is oxygen, the fiber may be represented by the following <Formula 2>.

<Formula 2>

CuP _x S _y

When the fibers constituting the anode electrode 300 are expressed as in <Formula 2>, x+y=1, 0.3≤x≤0.7, and 0.3≤y≤0.7.

If, in <Formula 2>, x is less than 0.3 or greater than 0.7, and y is less than 0.3 or greater than 0.7, ORR, OER, and HER characteristics of the positive electrode 300 may be reduced, and thus In the charging/discharging process of the secondary battery including the positive electrode 300 , the positive electrode 300 may not reversibly react.

However, according to the embodiment of the present application, when the positive electrode 300 is expressed as CuP _x S _y , the composition ratio of P may be 0.3 or more and 0.7 or less, and the composition ratio of S may be 0.3 or more and 0.7 or less. Accordingly, ORR, OER, and HER characteristics of the positive electrode 300 may be improved, and charge/discharge characteristics and lifespan characteristics of the secondary battery including the positive electrode 300 may be improved.

When the secondary battery including the positive electrode 300 performs charging and discharging, the lattice spacing of the fibers included in the positive electrode 300 may be reversibly changed. Specifically, when the secondary battery is charged, the lattice spacing may be 0.478 nm, and when the secondary battery is discharged, the lattice spacing may be 0.466 nm. The lattice spacing of the fibers can be confirmed by HRTEM.

According to an embodiment of the present application, in a method of mixing the first precursor having the chalcogen element, the second precursor having phosphorus, and the third precursor having the transition metal, and co-precipitating and heat treatment under pressure, fibrils The positive electrode 300 in the form of a membrane in which the plurality of fibers formed into a network may be manufactured.

The positive electrode 300 having high electrochemical properties can be manufactured by an inexpensive method.

In addition, the positive electrode 300 is manufactured by co-precipitation and pressure heat treatment, so that mass production is easy and the manufacturing process is simplified, and the positive electrode of the secondary battery can be provided.

Hereinafter, specific experimental examples of the present application and characteristic evaluation results thereof will be described.

Preparation of negative electrode according to Experimental Example 1-1

A zinc foil was prepared as a base metal substrate. The zinc foil was sonicated with HCl for 5 minutes and washed with deionized water and ethanol.

Prepare a parana solution in which H ₂ SO ₄ , H ₂ O and NH ₄ OH are mixed in 2.5:7:0.5 (v/v/v), and treat zinc foil with the pirana solution to improve hydrophilic properties, After washing with deionized water, it was dried in nitrogen and argon gas atmosphere.

Polystyrene beads were prepared and spin-coated on zinc foil, and oxygen plasma was applied at 60 mTorr, 30 sccm flow rate, and 80 W RF conditions, and the polystyrene beads were etched to reduce their size.

Thereafter, a photosensitive material having chromium was coated on a zinc foil having polystyrene beads to prepare a mask film, and the polystyrene beads were removed. _{Thereafter, using the mask film as a mask, an etching gas containing argon gas and SF 6} gas is provided at 0.1 Pa, 40 sccm flow rate, and 60 W RF conditions to form a plurality of grooves having a depth of 500 nm and a diameter of 500 nm in the zinc foil. formed.

The mask film was removed, _{sonicated using dilute H 2} SO ₄ , and dried in an argon gas atmosphere to prepare a negative electrode according to Experimental Example 1-1.

14 is an SEM photograph of a cathode electrode according to Experimental Example 1-1 of the present application.

Referring to FIG. 14 , an SEM photograph of the negative electrode according to Experimental Example 1-1 was taken, and it can be seen that a plurality of grooves spaced apart from each other were formed in the zinc foil.

Preparation of negative electrode according to Experimental Example 1-2

An unpatterned zinc foil was prepared as a negative electrode according to Experimental Example 1-2.

Preparation of base complex feeding oil (CBC) according to Experimental Example 2-1

Acetobacter xylinum was prepared as a bacterial strain, and a chitosan derivative was prepared. The chitosan derivative is a suspension of 1 g of chitosan chloride dissolved in 1% (v/v) aqueous acetic acid with 1 M glycidyltrimethylammonium chloride in N2 atmosphere at 65° C. for 24 hours. After treatment, it was prepared by precipitation and filtration multiple times with ethanol.

Pineapple juice (2% w/v), yeast (0.5% w/v), peptone (0.5% w/v), disodium phosphate (0.27% w/v), citric acid (0.015% w/v), and the above A Hestrin-Schramm (HS) culture medium containing a chitosan derivative (2% w/v) was prepared and steam sterilized at 121° C. for 20 minutes. In addition, Acetobacter xylinum was activated in a pre-cultivation Hestrin-Schramm (HS) culture medium at 30° C. for 24 hours, and then maintained at pH 6 by adding acetic acid.

Then, Acetobacter xylinum was cultured in Hestrin-Schramm (HS) culture medium at 30 °C for 7 days.

The harvested bacterial pellicles were washed with deionized water to neutralize the pH of the supernatant and dehydrated in vacuum at 105°C. The resulting cellulose was demineralized with 1 N HCl for 30 minutes (mass ratio 1:15, w/v) to remove excess reagent, and then using deionized water several times until the supernatant became neutral pH. It was purified by centrifugation. Finally, after evaporating all solvents at 100 °C, the base composite fiber (chitosan-bacterial cellulose (CBC)) according to the experimental example was prepared.

Preparation of first composite fiber (oCBC) according to Experimental Example 2-2

15 is a view for explaining a manufacturing process of a first composite fiber according to Experimental Example 2-2 of the present application.

The first composite fibers (TEMPO-oxidized CBCs (oCBCs)) on which the surface of the base composite fibers are oxidized, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), By oxidation using sodium bromide (NaBr) and sodium hypochlorite (NaClO), hydroxymethyl and ortho-para directing acetamido-based composite fibers (CBC) were conjugated to the oxide of TEMPO. designed in this way.

Specifically, 2 g of the base composite fiber fibers dispersed in 2 mM TEMPO aqueous solution were reacted with NaBr (1.9 mM). 5 mM NaClO was used as an additional oxidizing agent.

The reaction suspension was stirred ultrasonically, and the reaction was allowed to proceed at room temperature for 3 hours. The pH of the suspension was maintained at 10 by continuous addition of 0.5M NaOH solution. Then, 1N HCl was added to the suspension to keep the pH neutral for 3 hours. The resulting oxidized pulp in the suspension was washed 3 times with 0.5 N HCl, and the supernatant was brought to neutral pH with deionized water.

The washed pulp was exchanged with acetone, toluene for 30 minutes and dried to evaporate the solvent, and finally, a first composite fiber (oCBC) fiber was obtained.

As can be seen from FIG. 15 , the surface of the base composite fiber may be oxidized.

Preparation of the second composite fiber (qCBC) according to Experimental Example 2-3

16 is a view for explaining a manufacturing process of a second composite fiber according to Experimental Example 2-3 of the present application.

A second composite (Covalently quaternized CBC (qCBC)) in which a first functional group having nitrogen is bonded to the base composite fiber is, as shown in FIG. 14, a coupling agent using 1,4-Diazabicyclo[2.2.2]octane It was prepared by a method of conjugation of a brominated base composite fiber (CBC) and a quaternary amine group by

Specifically, 1 g of the base composite fiber dispersed in N,N-dimethylacetamide (35 ml) solution was reacted with a LiBr (1.25 g) suspension with stirring for 30 minutes. N-bromosuccinimide (2.1 g) and triphenylphosphine (3.2 g) were used as coupling agents. The two reaction mixtures were stirred for 10 minutes and reacted at 80° C. for 60 minutes.

The reaction suspension was then cooled to room temperature and added to deionized water, filtered, rinsed with deionized water and ethanol, and freeze-dried to obtain brominated base conjugate fiber (bCBC) fibers.

The brominated base composite fiber was dissolved in 100 ml of N,N-dimethylformamide and reacted with 1.2 g of 1,4-Diazabicyclo[2.2.2]octane.

Thereafter, the mixture was sonicated for 30 minutes and then reacted at room temperature for 24 hours. The resulting solution was mixed with diethyl ether, washed with diethyl ether/ethyl acetate 5 times, and freeze-dried to obtain a second composite fiber (Covalently quaternized CBC (qCBC)).

As can be seen from FIG. 16 , it can be confirmed that the first functional group having nitrogen is bonded to the surface of the base composite fiber.

Preparation of solid electrolytes (CBCs) according to Experimental Examples 2-4 to Experimental Examples 2-8

17 is a view for explaining a method of manufacturing a solid electrolyte according to an experimental example of the present application.

The solid electrolyte was prepared by a gelatin process using the first composite fiber (oCBC) and the second composite fiber (qCBC), as shown in FIG. 17 . Specifically, the first composite fiber (oCBC) and the second composite fiber (qCBC) were mixed with methylene chloride and 1,2-Propanediol and acetone in the same weight ratio using ultrasound (8:1:1 v/v). /v%), 1wt% of glutaraldehyde as a crosslinking agent and 0.3wt% of N,N-Diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide as an initiator were added.

A vacuum chamber (200 Pa) was used to remove air bubbles from the gel suspension and cast on glass at 60° C. for 6 hours. The composite fiber membrane was peeled off while coagulated with deionized water, rinsed with deionized water, and vacuum dried.

Solid electrolytes (CBCs) were prepared by ion exchange with 1 M KOH aqueous solution and 0.1 M ZnTFSI at room temperature for 6 hours, respectively. Thereafter, in order to avoid reaction and carbonate formation with _{CO 2} , washing and immersion processes were performed with deionized water in an _{N 2 atmosphere.}

As can be seen in FIG. 17 , it can be seen that the first conjugated fibers (oCBC) and the second conjugated fibers (qCBC) are cross-linked with each other to constitute the solid electrolytes (CBCs). On the surfaces of the crosslinked first composite fibers (oCBC) and the second composite fibers (qCBC) of the solid electrolytes (CBCs), OH ions are hopping (hopping, Grotthuss transport), and the first composite The fiber and the inside spaced apart from the surface of the second composite fiber may move through diffusion. In addition, the solid electrolytes (CBCs) may have an amorphous phase, and thus may have high ionic conductivity compared to a crystalline structure.

In the manufacturing process of the solid electrolytes (CBCs), the ratio of the first conjugated fiber (oCBC) and the second conjugated fiber (qCBC) was adjusted as shown in Table 1 below.

division first composite fiber second composite fiber Experimental Example 2-4 10wt% 90wt% Experimental Example 2-5 30wt% 70wt% Experimental Example 2-6 50wt% 50wt% Experimental Example 2-7 70wt% 30wt% Experimental Example 2-8 90wt% 10wt%

Preparation of solid electrolytes according to Experimental Examples 2-9 to Experimental Examples 2-13

A base composite fiber was prepared according to Experimental Example 2-1 described above, but the base composite fiber having a different chitosan content was prepared by adjusting the addition ratio of the chitosan derivative. Thereafter, solid electrolytes according to Experimental Examples 2-9 to 2-13 were prepared as shown in Table 2 by using the base composite fibers having different chitosan contents according to Experimental Examples 2-6 described above.

division proportion of chitosan Experimental Example 2-9 10wt% Experimental Example 2-10 30wt% Experimental Example 2-11 50wt% Experimental Example 2-12 70wt% Experimental Example 2-13 90wt%

Preparation of positive electrode according to Experimental Example 3

Prepare dithiooxamide as a first precursor having sulfur, prepare a mixture (1:1 M%) of tetradecylphosphonic acid and ifosfamide as a second precursor having phosphorus, prepare copper chloride as a third precursor having copper, and prepare as a solvent A mixture of ethanol and ethylenediamine (1:3v/v%) was prepared.

After the first to third precursors were added to the solvent, a suspension was prepared by stirring.

Thereafter, 2.5M% of ammonium hydroxide was added as a first reducing agent, stirred for 2 hours, and heat treated at 120° C. for 6 hours, after which an intermediate product was obtained, washed with deionized water and ethanol, and dried in a vacuum at 50° C. did.

In an ice bath, the intermediate product was mixed and stirred in 20 ml of deionized water with Triton X-165 as a secondary reducing agent and sodium bisulfite as an elemental sulfur source. Thereafter, pressure heat treatment was performed at 120° C. for 24 hours to prepare a membrane in which a plurality of fibrillated fibers formed of a compound of copper, phosphorus, and sulfur constitute a network.

The membrane was washed with deionized water and ethanol, adjusted to neutral pH, stored at -70°C for 2 hours, immersed in liquid nitrogen, and freeze-dried in vacuum, CuPS according to Experimental Example 3 in which (101) crystal plane was developed A positive electrode was prepared.

In the manufacturing process of the positive electrode according to Experimental Example 3, by adjusting the ratio of the first precursor having sulfur and the second precursor having phosphorus, the ratios of P and S in CuPS were 0.1:0.9, 0.2:0.8, respectively. Adjusted to 03:0.7, 0.5:0.5, 0.7.0.3, and 0.9:0.1.

18 is a photograph of the positive electrode according to Experimental Example 3 of the present application.

Referring to FIG. 18 , the positive electrode (CuP _0.5 S _0.5 ) prepared according to Experimental Example 3 described above was photographed. It can be seen that the positive electrode according to Experimental Example 3 has a length of about 10 cm and is flexible.

Secondary battery manufacturing according to Experimental Example 4

A cathode electrode having a plurality of grooves having a depth of 500 nm and a diameter of 500 nm according to Experimental Example 1-1, a solid electrolyte according to Experimental Examples 2-6, and a CuPS positive electrode having a ratio of P and S of 0.5:0.5 according to Experimental Example 3 A secondary battery (zinc air battery) according to Experimental Example 4 was manufactured in a pouch type using

Specifically, the positive electrode (90wt%), super P carbon (5wt%), and PTFE (5wt%) according to Experimental Example 3 were mixed in N-methyl-pyrrolidone containing 0.5wt% of Nafion solution to prepare a slurry. The slurry was coated on a stainless steel mesh and the solvent was evaporated. Then, it was cut into 6cm x 1.5cm size and dried in vacuum.

Thereafter, the anode electrode prepared and cut by the above-described method and the solid electrolyte of Experimental Example 2-6 were laminated and bent, and then the negative electrode of Experimental Example 1-1 was placed in the bending region and pressure was applied to the Experimental Example A secondary battery of No. 4 (zinc air battery) was prepared.

19 is an SEM image of a cross-section of a secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 19 , according to Experimental Example 4 of the present application, a cross-section of a secondary battery having the negative electrode of Experimental Example 1-1, the solid electrolyte of Experimental Example 2-6, and the CuPS positive electrode of Experimental Example 3 was photographed. .

19 , the negative electrode is provided in a sandwiched form between the solid electrolyte and the positive electrode, and the interface between the negative electrode and the solid electrolyte and the interface between the solid electrolyte and the positive electrode can be confirmed. have.

20 is an XRD measurement result of the negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.

Referring to FIG. 20 , XRD measurement was performed on the negative electrode according to Experimental Example 1-1 and Experimental Example 1-2.

As can be seen from FIG. 20 , when the patterning process is not performed according to Experimental Example 1-2, it can be confirmed that the peak value corresponding to the 002) crystal plane is higher than the peak value corresponding to the (100) crystal plane. On the other hand, when the patterning process was performed according to Experimental Example 1-1, the peak value for the (002) crystal plane decreased, so that the peak value corresponding to the (002) crystal plane was lower than the peak value corresponding to the (100) crystal plane. can be checked

In other words, the fact that the peak value corresponding to the (002) crystal plane is lower than the peak value corresponding to the (100) crystal plane may be a material characteristic due to the method of manufacturing the negative electrode according to the embodiment of the present application.

21 is a graph measuring a change in resistance to mechanical deformation of a negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.

Referring to FIG. 21 , bending was performed 20,000 times while applying pressure to the negative electrode according to Experimental Example 1-1 and Experimental Example 1-2, and a change in resistance according to the number of bending was measured.

As can be seen from FIG. 21 , it can be seen that the resistance of the cathode electrode of Experimental Example 1-2, in which the patterning process is not performed, is rapidly increased after bending 5,600 times. On the other hand, it can be seen that the negative electrode of Experimental Example 1-1 having a plurality of grooves due to the patterning process has no substantial resistance change even after the bending process is performed 20,000 times or more.

In conclusion, it can be confirmed that the negative electrode of Experimental Example 1-1 has excellent mechanical properties and flexibility.

22 is an XPS analysis result of the interfacial layer of the negative electrode after 100 times of charging and discharging of the secondary battery including the negative electrode according to Experimental Example 1-1 of the present application, and FIG. XPS analysis results of the interfacial layer of the negative electrode after 6,000 charge and discharge of the secondary battery including the negative electrode.

22 and 23 , after charging and discharging 100 times and 6,000 times for the secondary battery of Experimental Example 4 including the negative electrode according to Experimental Example 1-1, XPS for the interfacial layer formed on the surface of the negative electrode Analysis was performed.

22 and 23 , the interfacial layer formed on the surface of the cathode electrode includes Zn, C, S, and F, and Zn-O, C=O, and C-O vibrations can be confirmed.

Although bonds such as Zn-F and Zn-S present in the interfacial layer are present at less than 5 at%, they perform an important function of stabilizing the surface of zinc electrodes. It can be confirmed that the elastic characteristics of the solid electrolyte according to the embodiment of the present application having

In addition, it can be seen that the ratio of Zn-F to Zn-S (ZnF/ZnS) increases as the charge/discharge cycle is performed, and after 6,000 charge/discharge cycles, it increases to about 8.6at% Able to know. This may be material and electrochemical characteristics due to the combination of the solid electrolyte and the negative electrode according to the embodiment of the present application.

24 is an XRD analysis result of solid electrolytes according to Experimental Examples 2-4 to 2-8 of the present application.

Referring to FIG. 24 , XRD analysis was performed on the solid electrolytes according to Experimental Examples 2-4 to 2-8 described above.

As can be seen in FIG. 24 , the solid electrolytes according to Experimental Examples 2-4 to 2-8 have peak values corresponding to the (101) and (002) crystal planes, and the first composite fiber (oCBC) and the second composite fiber According to the ratio of the fiber (qCBC), the crystal structure is not substantially changed, but it can be seen that the 2θ value of the peak value corresponding to the (002) crystal plane slightly increases as the ratio of the second composite fiber increases.

25 is a graph illustrating ionic conductivity measurements according to temperature of solid electrolytes according to Experimental Examples 2-4 to 2-8 of the present application.

Referring to FIG. 25 , the ionic conductivity of the solid electrolytes according to the above-described Experimental Examples 2-4 to 2-8 was measured according to temperature, and the ionic conductivity of the commercially available A201 membrane was measured and compared according to the temperature. did.

As can be seen from FIG. 25 , as the temperature increased, the ionic conductivity of the solid electrolyte and the A201 membrane according to Experimental Examples 2-4 to 2-8 increased. In addition, it can be seen that the ionic conductivity of the solid electrolytes according to Experimental Examples 2-4 to 2-8 is significantly higher than that of the A201 membrane.

In addition, according to Experimental Example 2-6, the ionic conductivity of the solid electrolyte having the same ratio of the first composite fiber and the second composite fiber was determined in Experimental Example 2-4, Experimental Example 2-5, Experimental Example 2-7, and Experimental Example 2-6. It can be confirmed that it is significantly higher than the solid electrolytes according to Examples 2-8. As a result, controlling the proportion of the first composite fiber to be more than 30 wt% and less than 70 wt% and controlling the proportion of the second conjugate fiber to less than 70 wt% and more than 30 wt% is an efficient way to improve the ionic conductivity of OH ions It can be confirmed that

26 shows measurements of ionic conductivity according to temperature of solid electrolytes and chitosan according to Experimental Examples 2-9 to 2-13 of the present application.

Referring to FIG. 26 , the ionic conductivity of the solid electrolytes and chitosan according to Experimental Examples 2-9 to 2-13 was measured according to temperature.

As can be seen from FIG. 26 , as the temperature increased, the ionic conductivity of the solid electrolyte and chitosan of Experimental Examples 2-9 to 2-13 increased. In addition, it can be seen that the ionic conductivity of the solid electrolytes according to Experimental Examples 2-9 to 2-13 is significantly higher than that of chitosan.

In addition, the ionic conductivity of the solid electrolyte having 50 wt% chitosan according to Experimental Example 2-11, Experimental Example 2-9, Experimental Example 2-10, Experimental Example 2-12, and Experimental Example 2-13 The solid electrolyte It can be seen that they are significantly higher than As a result, it can be confirmed that controlling the proportion of chitosan in the solid electrolyte to be more than 30 wt% and less than 70 wt% is an effective method for improving the ionic conductivity of OH ions.

27 is a measurement of the swelling ratio according to the temperature of the solid electrolyte and chitosan according to Experimental Examples 2-9 to 2-13 of the present application.

Referring to FIG. 27 , the swelling ratio of the solid electrolyte and chitosan according to Experimental Examples 2-9 to 2-13 described above was measured according to temperature.

As can be seen from FIG. 27 , as the temperature increased, the swelling ratio of the solid electrolyte and chitosan according to Experimental Examples 2-9 to 2-13 increased. In addition, according to Experimental Example 2-11, the swelling ratio of the solid electrolyte having 50wt% chitosan was the solid electrolyte according to Experimental Examples 2-9, Experimental Example 2-10, Experimental Example 2-12, and Experimental Example 2-13. It can be seen that they are significantly lower than As a result, it can be confirmed that controlling the proportion of chitosan in the solid electrolyte to be more than 30 wt% and less than 70 wt% is an effective way to reduce the swelling ratio.

28 is an XRD graph of the positive electrode prepared according to Experimental Example 3 of the present application.

Referring to FIG. 28 , XRD measurement was performed on the positive electrode prepared according to Experimental Example 3.

28 , the positive electrode of Experimental Example 3 had a (101) crystal plane, a (111) crystal plane, a (210) crystal plane, a (120) crystal plane, a (220) crystal plane, and a (022) crystal plane. It has a (103) crystal plane and a (222) crystal plane, and in particular, it can be seen that the size of the peak corresponding to the (101) crystal plane is significantly higher than the peak values corresponding to the crystal plane other than the (101) crystal plane. In addition, it can be seen that the anode electrode of Experimental Example 3 has a covellite phase as a Pnm21 space group with an orthorhombic crystal structure.

29 is a HRTEM photograph of the positive electrode according to Experimental Example 3 in the charging/discharging state of the secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 29 , in the charging and discharging states of the secondary battery according to Experimental Example 4, an HRTEM photograph of the positive electrode according to Experimental Example 3 was taken. As the positive electrode according to Experimental Example 3, CuP _0.1 S _0.9 , CuP _0.5 S _0.5 , and CuP _0.9 S _0.1 were used. 29 a, b, c are _{HRTEM pictures of CuP 0.1} S _0.9 , d, e, f are _{HRTEM pictures of CuP 0.5} S _0.5 , g, h, i of CuP _0.9 S _0.1 This is an HRTEM picture.

As can be seen from FIG. 29 , in the case of CuP _0.1 S _0.9 and CuP _0.9 S _{0.1 ,} the redox band of Cu is higher than the S 3p band, and the oxidized sulfur may be unstable. For this reason, as shown in FIG. 29 , it can be confirmed that the grid spacing is not reversibly recovered even when charging and discharging are performed. On the other hand, in _{the case of CuP 0.5} S _0.5, the lattice spacing before charging is 0.466 nm, the lattice spacing after charging is 0.478 nm, the lattice spacing after discharging is 0.466 nm, and after charging and discharging, the lattice spacing is reversible. recovery can be seen.

30 is a graph evaluating ORR, OER, and HER characteristics according to the composition ratio of P and S of the positive electrode according to Experimental Example 3 of the present application.

Referring to FIG. 30 , in the CuPS electrode structure according to Experimental Example 3, ORR, OER, and HER characteristics according to the composition ratio of P and S were measured and shown.

As can be seen from FIG. 30 , in the CuPS electrode structure, when the composition ratio of P is greater than 0.3 and less than 0.7, and the composition ratio of S is less than 0.7 and greater than 0.3, it can be confirmed that ORR, OER, and HER characteristics are excellent. In other words, in the CuPS electrode structure, it can be confirmed that controlling the composition ratio of P to be greater than 0.3 and less than 0.7 and the composition ratio of S to be less than 0.7 and greater than 0.3 is an efficient method to improve ORR, OER, and HER characteristics. .

31 is a graph evaluating OER, ORR, and HER characteristics according to a crystal plane in the positive electrode according to Experimental Example 3 of the present application.

Referring to FIG. 31 , according to the crystal plane of the CuPS electrode structure according to Experimental Example 3, overpotentials for OER and ORR reactions (bifunctional activity) and overpotentials for HER reactions were calculated using discrete Fourier transforms.

As can be seen from FIG. 31 , it can be confirmed that the overpotential value of the (101) crystal plane is the lowest, and accordingly, the ORR, OER, and HER characteristics of the electrode structure in which the (101) crystal plane is developed according to the embodiment of the present application are improvement can be seen.

In conclusion, it can be seen that manufacturing the positive electrode having a (101) crystal plane and using it as a positive electrode of a zinc-air battery is an efficient method for improving the charge/discharge characteristics of a zinc-air battery.

32 is a graph for explaining charge/discharge characteristics in a bending state of a secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 32 , charging and discharging were performed under ^{25 mAcm -2} conditions while sequentially bending the secondary battery according to Experimental Example 4 at 0°, 90°, 180°, and 0°.

As can be seen from FIG. 32 , it can be confirmed that the secondary battery according to Experimental Example 4 has no substantial effect on charging and discharging characteristics even when bent at various angles. That is, it can be confirmed that a flexible secondary battery can be implemented by using the negative electrode, the solid electrolyte, and the positive electrode according to the embodiment of the present application.

33 is a graph for explaining a change in capacity and efficiency according to the number of times of charging and discharging in a bending state of the secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 33 , the secondary battery prepared according to Experimental Example 4 was bent by 180°, and charging and discharging were performed under ^{25 mAcm -2 conditions.}

As can be seen in FIG. 33 , even if the number of charge/discharge cycles is performed in a state bent at 180°, it can be confirmed that the battery is stably driven without substantially lowering the charge/discharge capacity and the coulombic efficiency.

34 is a graph evaluating long-term stability in a bending state of a secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 34 , the secondary battery according to Experimental Example 4 was bent by 180° and charged and discharged 6,000 times for 8 hours under the condition of 25 ^{mAcm -2 .}

As can be seen from FIG. 34 , it can be seen that the secondary battery according to Experimental Example 4 is stably driven in a bent state, and there is no substantial degradation in characteristics in the bent state even when the number of charge and discharge increases.

35 is a graph for comparing charge/discharge characteristics of a secondary battery in a bending state with other batteries according to Experimental Example 4 of the present application.

Referring to FIG. 35 , a secondary battery (Pt/C+RuO _{2 ) was prepared by exchanging the positive electrode with Pt/C and RuO 2} in the secondary battery according to Experimental Example 4, PVA electrolyte, zinc foil, and Pt/C and RuO ₂ to prepare a commercially available zinc-air battery, and compare charge and discharge characteristics in a bent state with other secondary batteries in Experimental Example 4.

As can be seen from FIG. 35 , in the case of a commercialized zinc-air battery, it can be seen that the characteristics are rapidly deteriorated in the bent state, so that the charging/discharging operation cannot be performed. In the case of the zinc-air battery including the Pt/C and RuO ₂ positive electrode, as the bending angle increased, the charge/discharge characteristics were rapidly deteriorated.

On the other hand, it can be seen that the secondary battery according to Experimental Example 4 of the present application is stably driven without change in charge/discharge characteristics at various bending angles.

As mentioned above, although the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to specific embodiments and should be construed according to the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

10: metal substrate
11: first bending area
12: second bending area
50: gas diffusion layer
100: cathode electrode
110: bead
120: mask film
122: etch target area
124: home
200: solid electrolyte
210: base composite fiber
210a: first composite fiber
210b: second composite fiber
212: cellulose
214: chitosan
216: first functional group
300: positive electrode
400: current collector

Claims (15)

a positive electrode, a solid electrolyte, and a negative electrode;
There is provided a laminated structure in which the positive electrode and the solid electrolyte are stacked,
The stacked structure is bent (bending) to provide a bending region between the stacked structures,
a secondary battery comprising the negative electrode provided in the bending region;
According to claim 1,
and an inner surface of the bending region includes the solid electrolyte, and the negative electrode is in contact with the solid electrolyte.
According to claim 1,
The stacked structure in which the positive electrode and the solid electrolyte are stacked, and the negative electrode provided in the bending region are defined as unit cells,
The unit cells are provided in plurality,
and a plurality of the unit cells are stacked on each other so that the positive electrode included in the unit cells adjacent to each other is in contact with each other.
4. The method of claim 3,
A plurality of the stacked unit cells are defined as a cell structure,
The cell structure is provided in plurality,
The plurality of cell structures is a secondary battery including those disposed so that the positive electrode included in the cell structure is in contact with each other.
According to claim 1,
The stacked structure in which the positive electrode and the solid electrolyte are stacked, and the negative electrode provided in the bending region constitute a unit cell,
The unit cells are provided in plurality,
A plurality of the unit cells are stacked on each other so that the anode electrodes included in the unit cells adjacent to each other are adjacent to each other,
A secondary battery further comprising a gas diffusion layer disposed between the adjacent unit cells.
6. The method of claim 5,
The plurality of stacked unit cells and the gas diffusion layer disposed between the unit cells are defined as a cell structure,
wherein the cell structure is disposed such that the positive electrodes are in contact with each other.
According to claim 1,
The laminated structure is bent to a first side and a second side opposite to the first side,
the cathode electrode is provided in a first bending region bent toward the first side;
and in a second bending region where the second side is bent, the positive electrodes of the stacked structure are in contact with each other and are folded.
8. The method of claim 7,
The stacked structure is alternately and repeatedly stacked on the first side and the second side to provide a plurality of the first bending regions and a plurality of the second bending regions,
The cathode electrode is provided in at least one of the plurality of first bending regions,
and wherein the positive electrodes of the stacked structure are in contact with each other in the plurality of second bending regions.
9. The method of claim 8,
The stacked structure in which the positive electrode and the solid electrolyte are stacked, and the plurality of negative electrodes provided in the plurality of first bending regions are defined as a cell structure,
The cell structure is provided in plurality,
The plurality of cell structures is a secondary battery including those disposed so that the positive electrode included in the cell structure is in contact with each other.
8. The method of claim 7,
The stacked structure is alternately and repeatedly stacked on the first side and the second side to provide a plurality of the first bending regions and a plurality of the second bending regions,
A plurality of the cathode electrodes are respectively provided in the plurality of the first bending regions,
and a plurality of gas diffusion layers are provided in the plurality of second bending regions.
11. The method of claim 10,
The stacked structure, the plurality of cathode electrodes provided in the plurality of first bending regions, and the plurality of gas diffusion layers provided in the plurality of second bending regions are defined as a cell structure,
The cell structure is provided in plurality,
The plurality of cell structures is a secondary battery including those disposed so that the positive electrode included in the cell structure is in contact with each other.
a positive electrode, a solid electrolyte, and a negative electrode;
There is provided a laminate structure in which the positive electrode, the solid electrolyte, and the negative electrode are sequentially stacked,
The laminate structure is bent to a first side and a second side opposite to the first side,
and in the first bending region bent toward the first side, the negative electrode contacts each other and is folded.
13. The method of claim 12,
The secondary battery further comprising a gas diffusion layer provided in the second bending region bent toward the second side.
13. The method of claim 1 or 12,
The positive electrode includes a compound of copper, phosphorus, and sulfur, and uses oxygen as a positive electrode active material,
The solid electrolyte comprises bacterial cellulose,
The negative electrode is a secondary battery containing zinc.
13. The method of claim 1 or 12,
and the positive electrode and the solid electrolyte are in the form of a membrane in which a plurality of fibers constitute a network.

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