KR20210106333A - Metal anode electrode, secondary battery comprising the same, and method of fabricating of the sames - Google Patents

Abstract

A metal cathode electrode is provided. The metal cathode electrode may have a first surface and a second surface opposite to the first surface, wherein a plurality of grooves may be provided in the first surface of the metal cathode electrode. The metal cathode electrode having a plurality of grooves can be manufactured in a high yield by a simple method.

Description

Metal anode electrode, secondary battery including same, and manufacturing method thereof

The present application relates to a negative electrode, a secondary battery including the same, and a manufacturing method thereof, and more particularly, to a metal metal negative electrode, a secondary battery including the same, and a manufacturing method thereof.

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.

According to these technical needs, various electrodes for secondary batteries have been developed.

For example, Korean Patent Publication No. 10-2019-0139586 discloses a carbon nanotube and RuO ₂ deposited on the surface of the carbon nanotube, wherein the RuO ₂ is deposited on a surface defect site of the carbon nanotube, The RuO ₂ has a particle size of 1.0 to 4.0 nm, and the RuO ₂ 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 a lithium-air battery is disclosed.

One technical problem to be solved by the present application is to provide a metal negative electrode, a secondary battery including the same, and a manufacturing method thereof.

Another technical problem to be solved by the present application is to provide a metal negative electrode having a low manufacturing cost and a simple manufacturing process, a secondary battery including the same, and a manufacturing method thereof.

Another technical problem to be solved by the present application is to provide a metal negative electrode having improved charge/discharge capacity, a secondary battery including the same, and a manufacturing method thereof.

Another technical problem to be solved by the present application is to provide a metal negative electrode having a long lifespan and high stability, a secondary battery including the same, and a manufacturing method thereof.

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 metal cathode electrode.

According to an embodiment, in the metal cathode electrode, as a result of XRD analysis, a peak value corresponding to a (002) crystal plane is lower than a peak value corresponding to a (100) crystal plane, and a peak value corresponding to a (101) crystal plane is a different crystal plane It may include a value higher than the peak value corresponding to .

According to an embodiment, the metal cathode electrode may include a first surface and a second surface opposite to the first surface, and a plurality of grooves spaced apart from each other are provided on the first surface.

According to an embodiment, in a plan view, the plurality of grooves may include a circular shape.

According to an embodiment, as a result of the XRD analysis, (102) a peak value corresponding to the crystal plane, a (103) peak value corresponding to the crystal plane, and a peak value corresponding to the (110) crystal plane are further observed, and a peak value corresponding to the (101) crystal plane is further observed. It may include lower than the peak value.

According to an embodiment, the metal negative electrode may include a zinc electrode.

In order to solve the above technical problem, the present application provides a metal-air battery.

According to an embodiment, the metal-air battery may include the metal negative electrode according to the above-described embodiment, the positive electrode catalyst on the metal negative electrode, and the electrolyte between the metal negative electrode and the positive electrode catalyst.

According to an embodiment, the metal-air battery includes a metal negative electrode, a positive electrode on the metal negative electrode, and a solid electrolyte disposed between the metal negative electrode and the positive electrode, wherein the metal negative electrode and the positive electrode As a result of XRD analysis of the electrode, it may include that a peak value corresponding to the same crystal plane is higher than a peak value corresponding to a different crystal plane, respectively.

According to an embodiment, each of the metal negative electrode and the solid electrolyte may include a peak value corresponding to a (101) crystal plane that is higher than a peak value corresponding to another crystal plane.

According to an embodiment, the metal negative electrode and the solid electrolyte may include contacting.

According to an embodiment, an interface layer in contact with the solid electrolyte is provided on the surface of the metal negative electrode, and the interface layer includes a compound of metal and fluorine included in the metal negative electrode, and the metal negative electrode It may contain a compound of the metal and sulfur contained in it.

In order to solve the above technical problem, the present application provides a method of manufacturing a metal negative electrode.

According to an embodiment, the method of manufacturing the metal cathode electrode includes preparing a flat base metal substrate, disposing a plurality of beads on the base metal substrate, and the base metal on which the plurality of beads are disposed. forming a mask film on a substrate, removing the plurality of beads to expose an etch target region of the base metal substrate that is not covered with the mask film, and using the mask film as a mask, The method may include etching the exposed region to be etched to form a metal cathode electrode.

According to an embodiment, the method of manufacturing the metal cathode electrode may further include reducing the sizes of the plurality of beads before forming the mask layer.

According to an embodiment, the method of manufacturing the metal cathode may further include hydrophilizing the surface of the base metal substrate before disposing the plurality of beads.

According to an embodiment, the etch target region may include a bonding surface of the base metal substrate and the plurality of beads.

In the metal cathode electrode according to an embodiment of the present application, a plurality of beads and a mask film are sequentially formed on a flat base metal substrate, the plurality of beads are removed, and the base metal substrate is formed by using the mask film as a mask. It may be prepared by an etching method.

Accordingly, the metal cathode electrode having a plurality of grooves can be manufactured in a high yield by a simple method.

In addition, with a simple method of controlling the depth and diameter of the plurality of grooves of the metal cathode electrode, it is possible to develop a specific crystal plane (eg, (101) crystal plane) of the metal cathode electrode, whereby the Electrochemical properties of the metal cathode electrode can be improved.

1 is a flowchart illustrating a method of manufacturing a metal negative electrode according to an embodiment of the present application.
2 to 4 are process flowcharts for explaining a method of manufacturing a metal negative electrode according to an embodiment of the present application.
5 is a view for explaining a secondary battery including a metal negative electrode according to an embodiment of the present application.
6 is a view for explaining a solid electrolyte included in a secondary battery including a metal negative electrode according to an embodiment of the present application.
7 is a view for explaining a positive electrode included in a secondary battery including a metal negative electrode according to an embodiment of the present application and a method of manufacturing the same.
8 and 9 are SEM pictures of the metal cathode electrode according to Experimental Example 1-1 of the present application.
10 is a view for explaining a manufacturing process of the first composite fiber according to Experimental Example 2-2 of the present application.
11 is a view for explaining a manufacturing process of a second composite fiber according to Experimental Example 2-3 of the present application.
12 is a view for explaining a method of manufacturing a solid electrolyte according to an experimental example of the present application.
13 is a photograph of the positive electrode according to Experimental Example 3 of the present application.
14 is an SEM image of a cross-section of a secondary battery according to Experimental Example 4 of the present application.
15 and 16 are XRD analysis results according to the diameter and depth of the grooves included in the metal negative electrode according to Experimental Example 1-1 of the present application.
17 is a graph for explaining a ratio of a (101) crystal plane to a (002) crystal plane according to the diameter and depth of a groove included in the metal cathode electrode according to Experimental Example 1-1 of the present application.
18 is a graph illustrating a change in lattice constant of a unit cell according to a diameter and a depth of a groove included in a metal cathode electrode according to Experimental Example 1-1 of the present application.
19 is a graph of measuring an overpotential according to a groove and a diameter of a metal cathode electrode according to Experimental Example 1-1 of the present application.
20 is an SEM photograph of a metal cathode electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.
21 is an XRD measurement result of a metal negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.
22 is a graph illustrating a measurement of a change in resistance to mechanical deformation of a metal negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.
23 is a graph of measuring overpotential according to the number of times of charging and discharging of a symmetric cell including a metal negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.
24 is an SEM photograph of the interfacial layer of the metal negative electrode according to the number of times of charging and discharging of the secondary battery including the metal negative electrode according to Experimental Example 1-1 of the present application.
25 is an XPS analysis result of the interfacial layer of the metal negative electrode after 100 times of charging and discharging of the secondary battery including the metal negative electrode according to Experimental Example 1-1 of the present application.
26 is an XPS analysis result of the interfacial layer of the metal negative electrode after 6,000 times of charging and discharging of the secondary battery including the metal negative electrode according to Experimental Example 1-1 of the present application.
27 is an EIS measurement result of a secondary battery including a metal negative electrode according to Example 1-1 of the present application.
28 is an XRD analysis result of solid electrolytes according to Experimental Examples 2-4 to 2-8 of the present application.
29 illustrates measurements of ionic conductivity according to temperature of solid electrolytes according to Experimental Examples 2-4 to 2-8 of the present application.
30 illustrates 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.
31 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.
32 is an XRD graph of a positive electrode prepared according to Experimental Example 3 of the present application.
33 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.
34 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.
35 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.
36 is a graph of measuring voltage values according to the number of times of charging and discharging of a secondary battery according to Experimental Example 4 of the present application.
37 is a photograph of a mobile phone charging screen using a secondary battery according to Experimental Example 4 of the present application.
38 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.
39 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.
40 is a graph evaluating long-term stability in a bending state of a secondary battery according to Experimental Example 4 of the present application.
41 is a graph for comparing the charge/discharge characteristics of the secondary battery according to Experimental Example 4 of the present application in a bending state with that of other batteries.
42 is a graph for explaining a change in charge/discharge characteristics according to an external temperature condition of a secondary battery according to Experimental Example 4 of the present application.
43 is a view for explaining the retention characteristics according to the number of times of charging and discharging in a low-temperature and high-temperature environment of the secondary battery according to Experimental Example 4 of the present application.
44 is a graph for explaining the charge/discharge characteristics according to the external temperature of the secondary battery according to Experimental Example 4 of the present application.
45 is a graph for explaining a change in charge/discharge characteristics according to a charge/discharge cycle according to an external temperature of a secondary battery 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.

1 is a flowchart illustrating a method of manufacturing a metal negative electrode according to an embodiment of the present application, and FIGS. 2 to 4 are process flowcharts illustrating a method of manufacturing a metal negative electrode according to an embodiment of the present application.

1 and 2, the base metal substrate 10 in the form of a flat plate is prepared (S110).

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 ( S120 ).

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.

1 and 3 , 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 ( S130 ).

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 ( S140 ).

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.

1 and 4 , after the etch target region 122 is exposed, the etched target region 122 of the base metal substrate 10 is exposed using the mask layer 120 as a mask. by etching, the metal cathode electrode 100 may be manufactured (S150).

By using the mask layer 120 as a mask, the etch target region 122 may be etched to provide a plurality of grooves 124 in the metal cathode electrode 100 . The plurality of grooves 124 may correspond to the etch target region 122 . The plurality of grooves 124 may not penetrate through the metal 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, characteristics of the metal cathode 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 metal negative electrode 100 , an interface layer may be formed on the surface (the first surface) of the metal 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 metal cathode electrode 100 may be controlled according to the diameter and depth 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 metal 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 of the peak value corresponding to the (101) crystal plane to the peak value corresponding to the (002) crystal plane ((101)/(002)), the electrochemical properties of the metal cathode electrode 100 This 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 secondary battery including the metal negative electrode 100 An overpotential 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 metal 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 metal cathode electrode 100 may be controlled according to the diameter and depth of the plurality of grooves 124 . Specifically, when the metal 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 metal cathode electrode 100 is increased. may increase, and the c-axis lattice constant may decrease.

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

Accordingly, the metal cathode electrode 100 having the plurality of grooves 124 may be manufactured with a high yield by a simple method.

In addition, in a simple method of controlling the depth and diameter of the plurality of grooves 124 of the metal negative electrode 100 , a specific crystal plane of the metal negative electrode 100 can be developed, and thereby, the metal Electrochemical properties of the negative electrode 100 may be improved.

FIG. 5 is a view for explaining a secondary battery including a metal negative electrode according to an embodiment of the present application, and FIG. 6 is a view for explaining a solid electrolyte included in a secondary battery including a metal negative electrode according to an embodiment of the present application 7 is a view for explaining a positive electrode included in a secondary battery including a metal negative electrode according to an embodiment of the present application and a method of manufacturing the same.

Referring to FIG. 5 , the secondary battery according to the embodiment of the present application may include a metal negative electrode 100 , a solid electrolyte 200 , a positive electrode 300 , and a current collector 400 .

The metal cathode electrode 100 may be the same as described with reference to FIGS. 1 to 4 .

The solid electrolyte 200 , the positive electrode 300 , and the current collector 400 are sequentially stacked and then bent, so that the positive electrode 100 is disposed between the bent solid electrolyte 200 . can be placed. In other words, the metal negative electrode 100 may be provided in a form sandwiched between the stacked solid electrolyte 200 , the positive electrode 300 , and the current collector 400 .

Hereinafter, with reference to FIG. 6 , the solid electrolyte 200 and a manufacturing method thereof will be described in detail.

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 metal 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.

Hereinafter, with reference to FIG. 7 , the anode electrode 300 and a manufacturing method thereof will be described in detail.

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 methanesulfonate , Sulfur powder, sulphates, N,N-Dimethylthioformamide, and may contain at least one of 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 such that a (101) crystal plane is developed in the anode electrode 300 in the same way as a (101) crystal plane is developed in the metal cathode electrode 200. (eg, ethanol and ethylenediamine are mixed 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. 7A .

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. 7B . 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 treatment under pressure, as shown in FIG. 7C , 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 are 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 metal negative electrode 100 and the solid electrolyte 200 described above, 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 a metal cathode 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 including argon gas and SF 6} gas was provided under 0.1 Pa, 40 sccm flow rate, and 60 W RF conditions to form a plurality of grooves in the zinc foil.

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

The depth and diameter of the plurality of grooves were adjusted as shown in Table 1 below by controlling the flow rate and supply time of the etching gas, and the time for applying the oxygen plasma. In order to control the depth of the plurality of grooves to 100 nm, 500 nm, 1,000 nm, and 3,000 nm, the flow rate and supply time of the etching gas are as shown in <Table 2>, and the diameters of the plurality of grooves are 100 nm, 300 nm, 500 m, 1,000 nm, The time for applying the oxygen plasma to control to 5,000 nm is shown in <Table 3> below.

Groove depth (nm) Groove diameter (nm) 100 500 500 100 500 300 500 500 500 1,000 500 5,000 1,000 500 3,000 500

Groove depth (nm) Etching gas flow (sccm) Serving Time(s) 100 10 10 500 40 60 1,000 80 100 3,000 120 150

Initial polystyrene bead diameter (nm) Oxygen plasma application time (s) Groove diameter (nm) 120 3 100 360 5 300 1,000 10 500 2,000 20 1,000 10,000 60 5,000

8 and 9 are SEM pictures of a metal cathode electrode according to an experimental example of the present application.

Referring to FIGS. 8 and 9 , in FIGS. 8 (a) to (c), the diameter of the groove is 500 nm, the depth is 100 nm, 500 nm, and 1,000 nm, respectively, and FIGS. 9 (a) to (d) ), the depth of the groove is 500 nm and the diameter is 100 nm, 300 nm, 500 nm, and 1,000 nm, respectively.

As can be seen from FIGS. 8 and 9 , it can be seen that a plurality of grooves spaced apart from each other are formed in the zinc foil.

Preparation of a metal cathode electrode according to Experimental Example 1-2

An unpatterned zinc foil was prepared as a metal 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

10 is a view for explaining a manufacturing process of the 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 are 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), as shown in FIG. 10 , 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. 10 , the surface of the base composite fiber may be oxidized.

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

11 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. 11, a coupling agent using 1,4-Diazabicyclo[2.2.2]octane It was prepared by a method of conjugation of a brominated base conjugate fiber (CBC) and a quaternary amine group.

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)).

11 , 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

12 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. 12 . 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. 12 , it can be confirmed that the first composite fiber (oCBC) and the second composite fiber (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 4 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 5> 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.

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

Referring to FIG. 13 , 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

According to Experimental Example 1-1, a metal negative electrode having a plurality of grooves having a depth of 500 nm and a diameter of 500 nm, 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 Using the electrode, a secondary battery (zinc air battery) according to Experimental Example 4 was manufactured in a pouch type.

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 solid electrolyte of Experimental Example 2-6 and the metal negative electrode of Experimental Example 1-1 were laminated together to prepare a secondary battery (zinc air battery) of Experimental Example 4.

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

Referring to FIG. 14 , according to Experimental Example 4 of the present application, a cross-section of a secondary battery having the metal negative electrode of Experimental Example 1-1, the solid electrolyte of Experimental Example 2-6, and the CuPS positive electrode of Experimental Example 3 is photographed did.

14 , the metal negative electrode is provided in a sandwiched form between the solid electrolyte and the positive electrode, and the interface between the metal negative electrode and the solid electrolyte and the interface between the solid electrolyte and the positive electrode is formed. can be checked

15 and 16 are XRD analysis results according to the diameter and depth of the grooves included in the metal negative electrode according to Experimental Example 1-1 of the present application.

15 and 16 , according to Experimental Example 1-1, XRD measurement was performed on a metal cathode electrode having grooves having different diameters and different depths. Specifically, FIG. 15 shows a change in the depth in a state in which the diameter is fixed at 500 nm, and FIG. 16 shows a change in the diameter in a state in which the depth is fixed at 500 nm.

As can be seen from FIGS. 15 and 16 , when the depth of the groove increases from 100 nm to 500 nm while the diameter of the groove is fixed at 500 nm, the peak values corresponding to the (100) crystal plane and the (101) crystal plane are increased, and It can be seen that peak values corresponding to , (001) crystal plane, (102) crystal plane, (103) crystal plane, and (110) crystal plane are decreased. In addition, on the other hand, when the depth of the groove exceeds 500 nm, it can be seen that the peak values corresponding to the (100) Guljang plane and the (101) crystal plane decrease.

In addition, when the diameter of the groove increases from 100 nm to 500 nm while the depth of the groove is fixed at 500 nm, the peak values corresponding to the (100) crystal plane and the (101) crystal plane increase, whereas the diameter of the groove increases at 500 nm If it exceeds (002), the peak value corresponding to the (002) crystal plane increases, and the peak value corresponding to the (100) crystal plane decreases. 100) It can be seen that the peak value corresponding to the crystal plane is larger than the peak value.

In conclusion, as the diameter and depth of the groove increase from 100 nm to 500 nm, the ratio of the peak value of the (101) crystal plane to the (002) crystal plane ((101)/(002)) increases, and the diameter and depth of the groove increase When it exceeds 500 nm, it can be seen that the ratio ((101)/(002)) of the peak value of the (101) crystal plane to the 002) crystal plane decreases.

17 is a graph for explaining a ratio of a (101) crystal plane to a (002) crystal plane according to the diameter and depth of a groove included in the metal cathode electrode according to Experimental Example 1-1 of the present application.

Referring to FIG. 17, as described with reference to FIGS. 15 and 16, the peak value of the (101) crystal plane for the (002) crystal plane according to the diameter and depth of the groove of the metal cathode electrode according to Experimental Example 1-1 The ratio was calculated.

As can be seen from FIG. 17 , the ratio of the peak value of the (101) crystal plane to the (002) crystal plane can be controlled by adjusting the depth and diameter of the groove of the metal cathode electrode, and the depth and diameter of the groove are 500 nm. In the case of , it can be confirmed that the ratio of the peak value of the (101) crystal plane to the (002) crystal plane has a maximum value.

18 is a graph illustrating a change in lattice constant of a unit cell according to a diameter and a depth of a groove included in a metal cathode electrode according to Experimental Example 1-1 of the present application.

Referring to FIG. 18 , the lattice constant change of the unit cell of the metal negative electrode according to the diameter and depth of the groove in the metal negative electrode according to Experimental Example 1-1 was measured.

As can be seen from FIG. 18 , the metal cathode electrode according to Experimental Example 1-1 has a hexagonal crystal structure, and as the diameter and depth of the grooves gradually increase, the c-axis lattice constant of the unit cell of the metal cathode electrode decreases. And it can be seen that the a-axis lattice constant increases.

19 is a graph of measuring an overpotential according to a groove and a diameter of a metal cathode electrode according to Experimental Example 1-1 of the present application.

Referring to FIG. 19 , a symmetric cell was constructed using the metal negative electrode of Experimental Example 1-1, and the overpotential according to the depth and diameter of the groove of the metal negative electrode was measured under the condition of ^{2 mAcm -2.} .

As can be seen from FIG. 19 , it can be confirmed that the metal cathode electrode has the lowest overpotential when the depth and diameter of the groove are 500 nm, which is, as described with reference to FIG. 17 , (002) for the crystal plane ( 101) It can be confirmed that the overpotential can be controlled according to the ratio of the peak value of the (101) crystal plane to the (002) crystal plane under the condition that the ratio of the peak value of the crystal plane is maximized.

20 is an SEM photograph of a metal cathode electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.

Referring to FIG. 20 , SEM pictures of the metal cathode electrodes according to Experimental Example 1-1 and Experimental Example 1-2 were taken. 20 (a) is an SEM photograph of the metal cathode electrode according to Experimental Example 1-2, and FIG. 20 (b) is an SEM photograph of the metal negative electrode (500 nm in diameter, 500 nm in depth) according to Experimental Example 1-1. .

As can be seen from FIG. 20 , grooves of substantially uniform size were formed on the surface of the metal cathode electrode of Experimental Example 1-1 in which patterning was performed, as compared with the metal cathode electrode of Experimental Example 1-2 in which no patterning was performed. that can be checked

In addition, the metal negative electrode of Experimental Example 1-1 had an electric double layer capacitance of 126uFcm ^-2 , and the metal negative electrode of Experimental Example 1-2 had an electric double layer capacitance of 1.86uFcm ^{-2 , which} was measured in Experimental Example 1-1 It can be confirmed that the metal negative electrode of , as compared to the metal negative electrode of Experimental Example 1-2, has significantly more electrochemically active surfaces. That is, it can be confirmed that the metal negative electrode of Experimental Example 1-1 has a large surface area and high capacity and mass transfer rate.

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

Referring to FIG. 21 , XRD measurements were performed on the metal cathode electrodes according to Experimental Example 1-1 and Experimental Example 1-2.

As can be seen from FIG. 21 , 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 manufacturing method of the metal cathode electrode according to the embodiment of the present application.

22 is a graph illustrating a measurement of a change in resistance to mechanical deformation of a metal negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.

Referring to FIG. 22 , bending was performed 20,000 times while applying pressure to the metal 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. 22 , it can be seen that the resistance of the metal cathode electrode of Experimental Example 1-2 in which the patterning process is not performed rapidly increases after bending 5,600 times. On the other hand, it can be seen that the metal cathode 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 metal negative electrode of Experimental Example 1-1 has excellent mechanical properties and flexibility.

23 is a graph of measuring overpotential according to the number of times of charging and discharging of a symmetric cell including a metal negative electrode according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.

Referring to FIG. 23 , a symmetric cell was constructed using the metal cathode electrodes according to Experimental Example 1-1 and Experimental Example 1-2 of the present application, and the overpotential was measured.

As can be seen from FIG. 23 , in the case of the non-patterned metal negative electrode of Experimental Example 1-2, a high overpotential of 148 mV was recorded in the first charging cycle, and decreased to 79 mV in the next cycle. On the other hand, in the case of the metal negative electrode of Experimental Example 1-1 in which the patterning process was performed, a constant and low overpotential of 20 mV was stably recorded during the charging and discharging cycles.

24 is an SEM photograph of the interfacial layer of the metal negative electrode according to the number of times of charging and discharging of the secondary battery including the metal negative electrode according to Experimental Example 1-1 of the present application.

Referring to FIG. 24 , SEM imaging of the solid electrolyte interphase formed on the surface of the metal negative electrode according to the number of charging and discharging of the secondary battery of Experimental Example 4 including the metal negative electrode according to Experimental Example 1-1 did. Fig. 24 (a) is an SEM photograph taken after charging and discharging 100 times, and Fig. 24 (b) is an SEM photograph taken after charging and discharging 6,000 times.

As can be seen from FIG. 24 , even after the secondary battery of Experimental Example 4 was charged and discharged 100 times and 6,000 times, deterioration of the interfacial layer of the metal negative electrode was not significant and it was confirmed that a stable state was maintained. In particular, it can be confirmed that the surface state is stable without dendrite growth, except that some pores are generated even after charging and discharging is performed.

In other words, by the interaction of the solid electrolyte having bacterial cellulose according to Experimental Example 2-6 and the zinc electrode having a plurality of grooves according to Experimental Example 1-1, an excellent interfacial layer is formed on the surface of the zinc electrode, thereby Therefore, it can be seen that dendrite growth is suppressed.

25 is an XPS analysis result of an interfacial layer of a metal negative electrode after 100 times of charging and discharging of a secondary battery including a metal negative electrode according to Experimental Example 1-1 of the present application, and FIG. 26 is Experimental Example 1-1 of the present application. XPS analysis results of the interfacial layer of the metal negative electrode after 6,000 times of charging and discharging of the secondary battery including the metal negative electrode according to

25 and 26, after charging and discharging 100 times and 6,000 times for the secondary battery of Experimental Example 4 including the metal negative electrode according to Experimental Example 1-1, the interfacial layer formed on the surface of the metal negative electrode XPS analysis was performed.

25 and 26 , the interfacial layer formed on the surface of the metal 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 metal negative electrode according to the embodiment of the present application.

27 is an EIS measurement result of a secondary battery including a metal negative electrode according to Example 1-1 of the present application.

Referring to FIG. 27 , EIS measurements were performed on the secondary battery of Experimental Example 4 including the metal negative electrode according to Experimental Example 1-1 after charging and discharging once, 100 times, and 6,000 times.

As can be seen from FIG. 27 , even when charging and discharging are performed, it can be confirmed that the charge transfer resistance does not substantially increase. That is, as described above, it can be seen that the interfacial layer is stably formed on the surface of the metal cathode electrode, and even if charging and discharging are performed, the charge transfer resistance does not increase.

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

Referring to FIG. 28 , 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. 28 , 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.

29 illustrates measurements of ionic conductivity according to temperature of solid electrolytes according to Experimental Examples 2-4 to 2-8 of the present application.

Referring to FIG. 29 , the ionic conductivity of the solid electrolytes according to Experimental Examples 2-4 to 2-8 described above was measured according to temperature, and the ionic conductivity of the commercially available A201 membrane was measured and compared according to temperature. did.

As can be seen from FIG. 29 , 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

30 illustrates 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. 30 , 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. 30 , 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.

31 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. 31 , 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. 31 , 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.

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

Referring to FIG. 32 , XRD measurement was performed on the positive electrode prepared according to Experimental Example 3.

32 , 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.

33 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. 33 , in the charging and discharging states of the secondary battery according to Experimental Example 4, HRTEM pictures of the positive electrode according to Experimental Example 3 were 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. 33 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. 33 , 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. 33 , 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.

34 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.

Referring to FIG. 34 , 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 illustrated.

As can be seen from FIG. 34 , 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. .

35 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. 35 , 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. 35 , 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.

36 is a graph of measuring voltage values according to the number of times of charging and discharging of a secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 36 , voltage values according to the number of times of charging and discharging were measured for the secondary battery according to Experimental Example 4 ^{under 50 mAcm −2} and 25 mA ^{−2 conditions.}

As can be seen from FIG. 36 , it can be confirmed that the battery is stably driven for about 6,000 charge/discharge times. That is, the CuPS electrode structure prepared according to the above-described embodiment of the present application may be stably used as a positive electrode together with a solid electrolyte, and the metal negative electrode manufactured according to the embodiment of the present application may be stably used as a negative electrode. It can be confirmed that there is

37 is a photograph of a mobile phone charging screen using a secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 37 , three pouch-type secondary batteries according to Experimental Example 4 were connected in series to generate 4.5V and connected to a mobile phone.

As shown in FIG. 37 , it can be confirmed that the mobile phone is charged using the secondary battery manufactured according to the embodiment of the present application.

38 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. 38 , charging and discharging were performed under ^{25 mAcm -2} conditions while sequentially bending at 0°, 90°, 180°, and 0° for the secondary battery according to Experimental Example 4.

As can be seen from FIG. 38 , 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 metal negative electrode, the solid electrolyte, and the positive electrode according to the embodiment of the present application.

39 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. 39 , 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. 39 , even if the number of charge/discharge cycles is performed in a state bent at 180°, it can be confirmed that the charging/discharging capacity and the coulombic efficiency are stably driven without substantial degradation.

40 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. 40 , the secondary battery according to Experimental Example 4 was bent 180° and charged and discharged 6,000 times for 8 hours under ^{25 mAcm -2 conditions.}

As can be seen from FIG. 40 , 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 if the number of times of charging and discharging is increased.

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

Referring to FIG. 41 , 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. 41 , in the case of a commercialized zinc-air battery, it can be seen that the characteristics of the commercialized zinc-air battery 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.

42 is a graph for explaining a change in charge/discharge characteristics according to an external temperature condition of a secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 42 , changes in charge/discharge characteristics were measured while changing the external temperature of the secondary battery according to Experimental Example 4 from -20°C to 80°C. 42 (b) shows that the current density is measured at ^{25 mAcm -2 .}

As can be seen from FIG. 42 , it can be seen that the voltage cap increases as the temperature increases, and has a low overpotential. That is, it can be confirmed that the secondary battery according to Experimental Example 4 of the present application can be stably driven in high temperature and low temperature environments.

43 is a view for explaining the retention characteristics according to the number of times of charging and discharging in a low-temperature and high-temperature environment of the secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 43 , a charge/discharge cycle was performed under ^{25 mAcm -2} conditions while controlling the external temperature of the secondary battery according to Experimental Example 4 to -20°C and 80°C. In FIG. 43, black indicates that the charge/discharge cycle was performed at -20°C, and red in FIG. 43 indicates that the charge/discharge cycle was performed at 80°C.

As can be seen from FIG. 43 , it can be confirmed that the high retention characteristics of about 94.5% are maintained and the operation is stably performed even after 1,500 charge/discharge cycles at high and low temperatures.

44 is a graph for explaining the charge/discharge characteristics according to the external temperature of the secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 44 , while controlling the external temperature of the secondary battery according to Experimental Example 4 to -20°C, 25°C, and 80°C, the ^{charge/discharge voltage was measured at 25mAcm -2} condition, and a Nyquist plot was shown. .

As can be seen from FIG. 44 , it can be confirmed that only a slight deterioration in properties is observed in a low-temperature environment, and stable operation is performed at low temperature, room temperature, and high temperature.

45 is a graph for explaining a change in charge/discharge characteristics according to a charge/discharge cycle according to an external temperature of a secondary battery according to Experimental Example 4 of the present application.

Referring to FIG. 45 , while controlling the external temperature of the secondary battery according to Experimental Example 4 to -20°C and 80°C, charging and discharging were performed 1,500 times for 200 hours at 25mAcm-2 condition. Figure 45 (a) is a result of charging and discharging at -20 ℃ condition, Figure 45 (b) is a result of performing charging and discharging at 80 ℃.

As can be seen from Figure 45, the charging and discharging characteristics are slightly deteriorated in a low-temperature environment of -20 ℃, but it can be confirmed that it is stably driven for a long time, and it can be confirmed that it is stably driven for a long time even in a high-temperature environment of 80 ℃ .

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
100: metal 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 (14)

with a metal cathode electrode,
As a result of XRD analysis, a peak value corresponding to a (002) crystal plane is lower than a peak value corresponding to a (100) crystal plane, and a peak value corresponding to a (101) crystal plane is higher than a peak value corresponding to another crystal plane. electrode.
According to claim 1,
The metal cathode electrode includes a first surface and a second surface opposite to the first surface,
and a plurality of grooves spaced apart from each other are provided on the first surface.
3. The method of claim 2,
In a plan view, the plurality of grooves are circular.
According to claim 1,
As a result of XRD analysis, (102) a peak value corresponding to a crystal plane, a (103) peak value corresponding to a crystal plane, and a peak value corresponding to a (110) crystal plane were more observed, but lower than the peak value corresponding to the (101) crystal plane A metal cathode electrode comprising a.
According to claim 1,
The metal negative electrode comprising a zinc electrode.
The metal cathode electrode according to claim 1;
an anode catalyst on the metal cathode electrode; and
and an electrolyte between the metal negative electrode and the positive catalyst.
metal cathode electrode;
an anode electrode on the metal cathode electrode; and
A solid electrolyte disposed between the metal negative electrode and the positive electrode,
As a result of XRD analysis of the metal negative electrode and the positive electrode, a peak value corresponding to the same crystal plane, respectively, is higher than a peak value corresponding to a different crystal plane.
8. The method of claim 7,
wherein the metal negative electrode and the positive electrode each have a peak value corresponding to a (101) crystal plane higher than a peak value corresponding to another crystal plane.
9. The method of claim 8,
and the metal negative electrode and the solid electrolyte are in contact with each other.
8. The method of claim 7,
On the surface of the metal negative electrode, an interfacial layer in contact with the solid electrolyte is provided,
The interfacial layer is a metal-air battery comprising a compound of metal and fluorine included in the metal negative electrode, and a compound of metal and sulfur included in the metal negative electrode.
Preparing a base metal substrate in the form of a flat plate;
disposing a plurality of beads on the base metal substrate;
forming a mask layer on the base metal substrate on which the plurality of beads are disposed;
removing the plurality of beads to expose a region to be etched of the base metal substrate that is not covered with the mask layer; and
and etching the exposed region to be etched of the base metal substrate using the mask layer as a mask to form a metal cathode electrode.
12. The method of claim 11,
Before forming the mask layer, the method of manufacturing a metal cathode electrode further comprising the step of reducing the size of the plurality of beads.
12. The method of claim 11,
Before disposing the plurality of beads, the method of manufacturing a metal negative electrode further comprising the step of hydrophilizing the surface of the base metal substrate.
12. The method of claim 11,
The etching target region may include a bonding surface between the base metal substrate and the plurality of beads.

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