Electrode structure, positive electrode structure for metal-air battery comprising the same, and method for manufacturing the same

Abstract

The present application provides an electrode structure for a positive electrode of a metal-air battery. The electrode structure for the positive electrode of the metal-air battery can include a film formed of a compound of copper, phosphorus, and sulfur and forming a network of a plurality of fibrillated fibers.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrode structure and a method for manufacturing the same, and more particularly, to an electrode structure including a membrane formed of a plurality of fibers, a positive electrode for a metal-air battery including the same, and a method for manufacturing the same. BACKGROUND

[0002] With the rapid growth of small devices and secondary batteries for home appliance products, and even large-scale high-energy applications such as electric vehicles and energy storage systems (ESS), the market value of the secondary battery industry is expected to grow from only about $22 billion in 2018 to about $118 billion in 2025. Therefore, in order to use secondary batteries as a medium for large-scale energy storage, it is necessary to have significantly improved price competitiveness, energy density, and stability compared to the current level.

[0003] According to these technical needs, various electrodes for secondary batteries are being developed.

[0004] For example, Korean Patent Laid-Open No. 10-2019-0139586 discloses an electrode for a lithium-air battery, which includes carbon nanotubes and RuO2 deposited on the surface of the carbon nanotubes, the RuO2 is deposited on a defect site of the surface of the carbon nanotubes, the particle size of the RuO2 is 1.0 nm to 4.0 nm, and the RuO2 suppresses carbon decomposition at the surface defect site of the carbon nanotubes and promotes the decomposition of Li2O2 formed on the surface of the carbon nanotubes. SUMMARY

[0005] TECHNICAL PROBLEM

[0006] The present application relates to an electrode structure and a method for manufacturing the same, and more particularly, to an electrode structure including a membrane formed of a plurality of fibers, a positive electrode for a metal-air battery including the same, and a method for manufacturing the same.

[0007] The present application relates to an electrode structure and a method for manufacturing the same, and more particularly, to an electrode structure including a membrane formed of a plurality of fibers, a positive electrode for a metal-air battery including the same, and a method for manufacturing the same.

[0008] The present application relates to an electrode structure and a method for manufacturing the same, and more particularly, to an electrode structure including a membrane formed of a plurality of fibers, a positive electrode for a metal-air battery including the same, and a method for manufacturing the same.

[0009] The present application relates to an electrode structure and a method for manufacturing the same, and more particularly, to an electrode structure including a membrane formed of a plurality of fibers, a positive electrode for a metal-air battery including the same, and a method for manufacturing the same.

[0010] The present application relates to an electrode structure and a method for manufacturing the same, and more particularly, to an electrode structure including a membrane formed of a plurality of fibers, a positive electrode for a metal-air battery including the same, and a method for manufacturing the same.

[0011] Another technical problem to be solved by the present application is to provide a positive electrode structure for a metal-air battery and a method of manufacturing the same, which has low manufacturing cost and simple manufacturing process.

[0012] Another technical problem to be solved by the present application is to provide a positive electrode structure for a metal-air battery and a method of manufacturing the same, which has improved redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics.

[0013] Another technical problem to be solved by the present application is to provide a positive electrode structure for a metal-air battery and a method of manufacturing the same, which has long lifespan and high stability.

[0014] The technical problem to be solved by the present application is not limited to the above.

[0015] Solution to the problem

[0016] To solve the above technical problem, the present application provides an electrode structure.

[0017] According to an embodiment, the above electrode structure can include a compound of a transition metal, phosphorus, and a chalcogen element, as a result of X-ray diffraction analysis (XRD), a peak value corresponding to a (101) crystal plane has a maximum value compared to peak values corresponding to other crystal planes, and includes a film formed of a plurality of fibers.

[0018] According to an embodiment, a peak value corresponding to a (101) crystal plane can be observed in a range of 2θ values of 19° to 21°.

[0019] According to an embodiment, the above transition metal can include at least one of copper, magnesium, manganese, cobalt, iron, nickel, titanium, zinc, aluminum, or tin, and the above chalcogen element can include at least one of sulfur, oxygen, selenium, or tellurium.

[0020] To solve the above technical problem, the present application provides an electrode structure for a positive electrode of a metal-air battery.

[0021] According to an embodiment, as the above electrode structure for a positive electrode of a metal-air battery, the above electrode structure can include a film formed of a compound of copper, phosphorus, and sulfur and forming a network of fibrillated plurality of fibers.

[0022] According to an embodiment, the above plurality of fibers formed of the compound of copper, phosphorus, and sulfur can include a plurality of trunks, and a plurality of branches branched from the plurality of trunks.

[0023] According to an embodiment, the plurality of trunks and the plurality of branches can be manufactured in different processes.

[0024] According to an embodiment, the above film of the above electrode structure can have a sponge structure, and the above electrode structure can have flexibility.

[0025] According to an embodiment, according to the charge and discharge states of the above-mentioned metal-air battery, the lattice spacing of the above-mentioned film of the above-mentioned electrode structure can reversibly increase or decrease, which can be observed by high-resolution transmission electron microscopy (HRTEM).

[0026] To solve the above-mentioned technical problem, the present application provides a metal-air battery.

[0027] According to an embodiment, the above-mentioned metal-air battery can comprise: a positive electrode comprising the above-mentioned electrode structure described in the above-mentioned embodiments, using oxygen as a positive active material; a negative electrode located above the positive electrode; and an electrolyte located between the positive electrode and the negative electrode.

[0028] According to an embodiment, in the discharge state of the above-mentioned metal-air battery, the high-resolution transmission electron microscopy analysis result of the above-mentioned film of the above-mentioned electrode structure can have a lattice spacing of 0.466 nm.

[0029] According to an embodiment, in the charge state of the above-mentioned metal-air battery, the high-resolution transmission electron microscopy analysis result of the above-mentioned film of the above-mentioned electrode structure can have a lattice spacing of 0.478 nm.

[0030] According to an embodiment, the X-ray diffraction analysis result of the above-mentioned film of the above-mentioned electrode structure can observe a base peak in the range of 2θ value of 18.5°-19.5°, and as the above-mentioned metal-air battery is charged in the discharge state, the 2θ value of the above-mentioned base peak observed in the range of 19°-21° can gradually decrease.

[0031] According to an embodiment, as the above-mentioned metal-air battery is charged in the discharge state, the above-mentioned base peak can be split into two.

[0032] According to an embodiment, in the discharge state of the above-mentioned metal-air battery, the phosphorus contained in the above-mentioned film can have an oxidation number of 2-, and in the charge state of the above-mentioned metal-air battery, the phosphorus contained in the above-mentioned film can have an oxidation number of 2- and n-(2

[0033] To solve the above-mentioned technical problem, the present application provides a method for preparing an electrode structure.

[0034] According to an embodiment, the method of manufacturing the electrode structure can include: a step of preparing a first precursor having a chalcogen element, a second precursor having phosphorus, and a third precursor having a transition metal; a step of mixing the first precursor, the second precursor, and the third precursor, and then adding a first reducing agent to prepare a mixture; a step of co-precipitating the mixture to prepare an intermediate product having a plurality of stems; and a step of preparing a fibrillated plurality of fibers including the transition metal, the chalcogen element, and phosphorus by branching a plurality of branches from the plurality of stems by adding a second reducing agent to the intermediate product and performing a pressurized heat treatment.

[0035] According to an embodiment, the above-mentioned first precursor can comprise dithiooxamide, dithiobiuret, dithiouracil, acetylthiourea, thiourea, N-methylthiourea, bis(phenylthio)methane, 2-imino-4-thiobiuret, N,N'-dimethylthiourea, ammonium sulfide, methylmethanesulfonate, sulfur powder, sulphates, N,N-dimethylthioformamide, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylthiourea, N,N'-dimethylThe second precursor can include at least one of tetradecylphosphonic acid, ifosfamide, octadecylphosphonic acid, hexylphosphonic acid, trioctylphosphine, phosphoric acid, triphenylphosphine, ammonium phosphide, pyrophosphates, Davy Reagent methyl, cyclophosphamide monohydrate, phosphorus trichloride, phosphorus (V) oxychloride, thiophosphoryl chloride, phosphorus pentachloride, or phosphorus pentasulfide, the third precursor can include at least one of copper chloride, copper (II) sulfate, copper (II) nitrate, copper selenide, copper oxychloride, cupric acetate, copper carbonate, copper thiocyanate, copper sulfide, copper hydroxide, copper naphthenate, or copper (II) phosphate.

[0036] According to an embodiment, the method of manufacturing the electrode structure can include a step of adding a chalcogen supply source having a chalcogen along with the second reducing agent.

[0037] According to an embodiment, the method of manufacturing the electrode structure can include a step of adding the second reducing agent in a cooled state.

[0038] According to an embodiment, the first reducing agent can include at least one of ammonium hydroxide, ammonium chloride, or tetramethylammonium hydroxide, and the second reducing agent can include at least one of 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 chloramine-T.

[0039] According to an embodiment, the chalcogen can be sulfur, and the transition metal can be copper.

[0040] Effects of the Invention

[0041] The method of preparing the electrode structure of the embodiment of the present application can include the steps of preparing a first precursor having a chalcogen, a second precursor having phosphorus, and a third precursor having a transition metal; mixing the first precursor, the second precursor, and the third precursor, and then adding a first reducing agent to prepare a mixture; co-precipitating the mixture to prepare an intermediate product having a plurality of stems; and branching a plurality of branches from the plurality of stems by adding a second reducing agent to the intermediate product and performing a pressurized heat treatment, to prepare a fibrillated plurality of fibers including the transition metal, the chalcogen, and phosphorus.

[0042] Accordingly, the preparation process of the electrode structure can be simplified, and the electrode structure can be easily prepared at a low cost.

[0043] Also, the electrode structure is composed of the film in which the plurality of fibers form a network, can have a flexible sponge structure, and can have high redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics. Due to the high electrochemical characteristics of the electrode structure, the charge and discharge capacity and the life characteristics of a metal-air battery using the electrode structure as a positive electrode can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 A flowchart for explaining a method of preparing an electrode structure for a positive electrode of a zinc-air battery according to an embodiment of the present application.

[0045] Figure 2 A diagram for explaining a preparation process of an electrode structure for a positive electrode of a zinc-air battery according to an embodiment of the present application.

[0046] Figure 3 A graph for photographing an electrode structure prepared according to Experimental Example 1 of the present application.

[0047] Figure 4 A stress-strain curve graph for an electrode structure prepared according to Experimental Example 1 of the present application.

[0048] Figure 5 An X-ray diffraction curve graph for an electrode structure prepared according to Experimental Example 1 of the present application.

[0049] Figure 6 An X-ray diffraction curve graph for an electrode structure prepared according to Experimental Example 2 of the present application.

[0050] Figure 7 An X-ray diffraction curve graph for an electrode structure prepared according to Experimental Example 3 of the present application.

[0051] Figure 8 An X-ray diffraction curve graph for an electrode structure prepared according to Experimental Example 4 of the present application.

[0052] Figure 9 A scanning electron microscope (SEM) graph for photographing an electrode structure of Experimental Example 1 of the present application.

[0053] Figure 10 A transmission electron microscope (TEM) graph for photographing an electrode structure of Experimental Example 1 of the present application.

[0054] Figure 11 An atomic structure simulation graph and a lattice fringe for an electrode structure of Experimental Example 1 of the present application.

[0055] Figure 12 A selected area electron diffraction (SEAD) graph for an electrode structure of Experimental Example 1 of the present application.

[0056] Figure 13 A high angle annular dark field-scanning transmission electron microscope (HAADF-STEM) graph for an electrode structure of Experimental Example 1 of the present application.

[0057] Figure 14 A curve graph for explaining a specific surface area and a pore of an electrode structure of Experimental Example 1 of the present application.

[0058] Figure 15 An X-ray photoelectron spectroscopy (XPS) measurement curve graph for electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4 of the present application.

[0059] Figure 16 An extended X-ray absorption fine structure (EXAFS) k2 X(k) R-space Fourier transform.

[0060] Figure 17 Cu 2p X-ray photoelectron spectroscopy spectrum chart of the electrode structure of Experimental Example 1, Experimental Example 3, and Experimental Example 4.

[0061] Figure 18 Cu L-edge X-ray absorption near-edge structure (XANES) spectrum chart of the electrode structure of Experimental Example 1, Experimental Example 3, and Experimental Example 4.

[0062] Figure 19 Cu K-edge X-ray absorption near-edge structure spectrum chart of the electrode structure of Experimental Example 1, Experimental Example 3, and Experimental Example 4, and a copper foil.

[0063] Figure 20 S K-edge X-ray absorption near-edge structure spectrum chart of the electrode structure of Experimental Example 1 and Experimental Example 3 of the present application.

[0064] Figure 21 S L-edge X-ray absorption near-edge structure spectrum chart of the electrode structure of Experimental Example 1 and Experimental Example 3 of the present application.

[0065] Figure 22 S 2p X-ray photoelectron spectroscopy spectrum chart of the electrode structure of Experimental Example 1 and Experimental Example 3 of the present application.

[0066] Figure 23 P K-edge X-ray absorption near-edge structure spectrum chart of the electrode structure of Experimental Example 1 and Experimental Example 4 of the present application.

[0067] Figure 24 P L-edge X-ray absorption near-edge structure spectrum chart of the electrode structure of Experimental Example 1 and Experimental Example 4 of the present application.

[0068] Figure 25 P 2p X-ray photoelectron spectroscopy spectrum chart of the electrode structure of Experimental Example 1 and Experimental Example 3 of the present application.

[0069] Figure 26 Thermogravimetric analysis (TGA) measurement results of the electrode structure of Experimental Example 1 of the present application.

[0070] Figure 27 Cyclic voltammogram (CV) chart for illustrating the redox reaction characteristics of the electrode structure of Experimental Example 1 and Experimental Example 2 of the present application.

[0071] Figure 28A cyclic voltammogram for explaining the redox reaction characteristics of the electrode structure and the Pt / C electrode of Experimental Example 3 and Experimental Example 4 of the present application.

[0072] Figure 29 A linear sweep voltammetry (LSV) graph for explaining the redox reaction characteristics of the electrode structure, the Pt / C electrode, and the carbon fiber of Experimental Example 1 to Experimental Example 4 of the present application.

[0073] Figure 30 A rotating ring disk electrode (RRDE) polarization plot and an electron transfer number graph of the electrode structure and the Pt / C electrode of Experimental Example 1 to Experimental Example 4 of the present application.

[0074] Figure 31 A graph for comparing the chemical durability of the electrode structure and the Pt / C electrode of Experimental Example 1 of the present application.

[0075] Figure 32 An electrochemical impedance spectroscopy (EIS) graph for explaining the redox reaction characteristics of the electrode structure and the carbon fiber of Experimental Example 1, Experimental Example 3, and Experimental Example 4 of the present application.

[0076] Figure 33 A linear sweep voltammetry and a cyclic voltammetry graph according to the number of cycles for explaining the redox reaction characteristics of the electrode structure of Experimental Example 1 of the present application.

[0077] Figure 34 A linear sweep voltammetry and a cyclic voltammetry graph according to the number of cycles for the Pt / C electrode.

[0078] Figure 35 A chronoamperometric measurement graph and a Faradaic efficiency measurement result for explaining the redox reaction characteristics of the electrode structure and the Pt / C electrode of Experimental Example 1 of the present application.

[0079] Figure 36 A gas chromatography measurement result for explaining the oxygen evolution reaction characteristics of the electrode structure of Experimental Example 1 of the present application.

[0080] Figure 37Linear sweep voltammetry curve and tafel plot for explaining the oxygen evolution reaction characteristics of the electrode structure, carbon fiber and RuO2 electrode of Experimental Example 1 to Experimental Example 4 of the present application.

[0081] Figure 38 Electrochemical impedance curve for explaining the oxygen evolution reaction characteristics of Experimental Example 1, Experimental Example 3, Experimental Example 4 and carbon fiber of the present application.

[0082] Figure 39 Linear sweep voltammetry curve according to the number of cycles for explaining the oxygen evolution reaction characteristics of the electrode structure and RuO2 electrode of Experimental Example 1 of the present application.

[0083] Figure 40 Chronoamperometry measurement curve and Faraday efficiency measurement result for explaining the oxygen evolution reaction characteristics of the electrode structure and RuO2 electrode of Experimental Example 1 of the present application.

[0084] Figure 41 Curve for explaining the bifunctional oxygen characteristics of the electrode structure, Pt / C electrode, RuO2 electrode and carbon fiber of Experimental Example 1 to Experimental Example 4 of the present application.

[0085] Figure 42 Curve for comparing the bifunctional oxygen characteristics of the electrode structure of Experimental Example 1 of the present application with other electrodes reported so far.

[0086] Figure 43 Linear sweep voltammetry curve for explaining the hydrogen evolution reaction characteristics of Experimental Example 1 to Experimental Example 4, Pt / C electrode and carbon fiber of the present application.

[0087] Figure 44 Chronoamperometry measurement curve for explaining the hydrogen evolution reaction characteristics of the electrode structure and Pt / C electrode of Experimental Example 1 of the present application.

[0088] Figure 45 Tafel curve for explaining the hydrogen evolution reaction characteristics of Experimental Example 1 to Experimental Example 4, Pt / C electrode and carbon fiber of the present application.

[0089] Figure 46 Linear sweep voltammetry curve according to the number of cycles for explaining the hydrogen evolution reaction characteristics of the electrode structure and Pt / C electrode of Experimental Example 1 of the present application.

[0090] Figure 47 Curve for comparing the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 of the present application with other electrodes reported so far.

[0091] Figure 48A linear sweep voltammetry curve for explaining the redox reaction characteristics of the electrode structure of Experimental Example 1 of the present application and the Pt / C electrode in an acidic environment.

[0092] Figure 49 A linear sweep voltammetry curve for explaining the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 of the present application and the Pt / C electrode in an acidic environment.

[0093] Figure 50 A curve for comparing the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 of the present application and other electrodes reported so far in an acidic environment.

[0094] Figure 51 A mass activity curve for comparing the redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics of the electrode structures of Experimental Examples 1 and 2, the Pt / C electrode, and the Ru02 electrode.

[0095] Figure 52 An in-situ X-ray diffraction measurement curve of the electrode structure of Experimental Example 1 of the present application under the charged and discharged state of the secondary battery of Experimental Example 1.

[0096] Figure 53 A high-resolution transmission electron microscope image of the electrode structure of Experimental Example 1 taken under the charged and discharged state of the secondary battery of Experimental Example 1 of the present application.

[0097] Figure 54 A Cu K-edge X-ray absorption near-edge structure spectrum curve of the electrode structure of Experimental Example 1 of the present application under the charged and discharged state of the secondary battery of Experimental Example 1.

[0098] Figure 55 SK-edge and P L-edge X-ray absorption near-edge structure spectrum curves of the electrode structure of Experimental Example 1 of the present application under the charged and discharged state of the secondary battery of Experimental Example 1.

[0099] Figure 56 SL 3,2 -edge X-ray absorption near-edge structure spectrum of the electrode structure of Experimental Example 1 of the present application under the charged and discharged state of the secondary battery of Experimental Example 1.

[0100] Figure 57 S2p X-ray photoelectron spectroscopy spectrum of the electrode structure of Experimental Example 1 of the present application under the charged and discharged state of the secondary battery of Experimental Example 1.

[0101] Figure 58 P2p X-ray photoelectron spectroscopy spectrum of the electrode structure of Experimental Example 1 of the present application under the charged and discharged state of the secondary battery of Experimental Example 1.

[0102] Figure 59 A high-resolution transmission electron microscope image of the electrode structure of Experimental Example 1 taken under a charge-discharge state of the secondary battery of Experimental Example 1 of the present application.

[0103] Figure 60 A graph of the characteristics of the oxygen evolution reaction, the redox reaction, and the hydrogen evolution reaction evaluated from the crystal plane in the electrode structure of Experimental Example 1 of the present application.

[0104] Figure 61 A graph of the characteristics of the redox reaction, the oxygen evolution reaction, and the hydrogen evolution reaction evaluated from the composition ratio of P and S of the electrode structure of Experimental Example 1 of the present application.

[0105] Figure 62 Cu 2p, P 2p, and S 2p X-ray photoelectron spectroscopy spectra of the composition ratio of P and S of the electrode structure of Experimental Example 1 of the present application.

[0106] Figure 63 A graph of the characteristics of the redox reaction, the oxygen evolution reaction, and the hydrogen evolution reaction evaluated from the composition ratio of Cu and S of the electrode structure of Experimental Example 3 of the present application.

[0107] Figure 64 An X-ray diffraction graph of the composition ratio of Cu and S of the electrode structure of Experimental Example 3 of the present application.

[0108] Figure 65 A graph showing the lattice parameters from the composition ratio of Cu and S of the electrode structure of Experimental Example 3 of the present application.

[0109] Figure 66 A graph comparing the discharge voltage from the current density of the zinc-air battery containing the electrode structure of Experimental Example 1 of the present application.

[0110] Figure 67 A graph for explaining the charge-discharge capacity of the zinc-air battery of Experimental Example 1 of the present application.

[0111] Figure 68 A graph measuring the voltage value from the number of charge-discharge of the zinc-air battery of Experimental Example 1 of the present application. DETAILED DESCRIPTION

[0112] Hereinafter, a preferred embodiment of the present application will be described in detail with reference to the accompanying drawings. However, the idea of the present application is not limited to the embodiment described herein, but can be embodied in other forms. The embodiment described herein is provided only to make the disclosure complete and complete and to fully convey the idea of the present application to those skilled in the art to which the present application belongs.

[0113] Furthermore, in the various embodiments of this specification, terms such as "first," "second," and "third" are used to describe various structural elements, but these structural elements are not limited by these terms. These terms are used only to distinguish one structural element from others. Therefore, a first structural element mentioned in one embodiment may also be mentioned as a second structural element in other embodiments. The embodiments described and illustrated herein also include supplementary embodiments. Furthermore, in this specification, "and / or" is used to mean including at least one of the structural elements listed above.

[0114] Unless explicitly stated in the context, singular expressions in this specification include plural expressions. Furthermore, terms such as "comprising" or "having" are intended to specify the presence of features, numbers, steps, structural elements, or combinations thereof described in the specification, and should not be construed as excluding the presence or additional possibilities of more than one other feature, number, step, structural element, or combination thereof. Also, in this specification, the term "connected" is used to include all cases where multiple structural elements are connected indirectly or directly.

[0115] Furthermore, in the following description of the present invention, detailed descriptions of known functions or structures will be omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the present invention.

[0116] Figure 1 This is a flowchart illustrating the method for preparing the positive electrode structure of the zinc-air battery according to embodiments of this application. Figure 2 This diagram illustrates the fabrication process of the positive electrode structure of the zinc-air battery according to embodiments of this application.

[0117] Reference Figure 1 and Figure 2 It is possible to prepare a first precursor containing chalcogens, a second precursor containing phosphorus, and a third precursor containing transition metals (step S110).

[0118] According to one embodiment, the aforementioned chalcogenide element may contain sulfur. In this case, for example, the aforementioned first precursor may contain at least one of dithiooxazone, dithiobiuret, dithiouracil, acetylthiourea, thiourea, N-methylthiourea, bis(phenylthio)methane, 2-imino-4-thiobiuret, N,N'-dimethylthiourea, ammonium sulfide, methyl methanesulfonate, sulfur powder, sulfate, N,N-dimethylthioformamide, or Davy reagent methyl.

[0119] Alternatively, according to other embodiments, the chalcogenide element may include at least one of oxygen, selenium, or tellurium.

[0120] For example, the second precursor can include at least one of tetradecylphosphonic acid, ifosfamide, octadecylphosphonic acid, hexylphosphonic acid, trioctylphosphine, phosphoric acid, triphenylphosphine, ammonium phosphide, pyrophosphate, Davy's reagent methyl, cyclophosphamide monohydrate, phosphorus trichloride, phosphorus oxychloride (V), thiophosphoryl chloride, phosphorus pentachloride, or phosphorus pentasulfide.

[0121] According to an embodiment, the second precursor can use different substances each other including phosphorus. For example, as the second precursor, a mixture of tetradecylphosphonic acid and ifosfamide mixed at 1:1 (M%) can 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, as described later, the positive electrode of the embodiment of the present application can have a covellite structure, and the electrochemical characteristics of the positive electrode can be improved.

[0122] According to an embodiment, the transition metal can include copper. In this case, for example, the third precursor can include at least one of copper chloride, copper (II) sulfate, copper (II) nitrate, copper selenide, copper oxychloride, copper acetate, copper carbonate, cuprous thiocyanate, copper sulfide, copper hydroxide, copper naphthenate, or copper (II) phosphate.

[0123] Alternatively, according to other embodiments, the transition metal can include at least one of magnesium, manganese, cobalt, iron, nickel, titanium, zinc, aluminum, or tin.

[0124] The first precursor, the second precursor, and the third precursor can be mixed and a first reducing agent can be added to prepare a mixture (step S120).

[0125] The first precursor, the second precursor, and the third precursor can be mixed in a solvent and then the first reducing agent can be added. For example, the solvent can be a mixture of ethanol and ethylenediamine. Alternatively, for example, the solvent can be a mixture of ethanol and toluene.

[0126] According to an embodiment, the direction of the crystal plane of the electrode structure body described later can be controlled according to the kind and mixing ratio of the solvent. In other words, the development of the (101) crystal plane in the electrode structure body can be controlled according to the kind and mixing ratio of the solvent, and thus the electrochemical characteristics of the electrode structure body can be controlled.

[0127] According to the embodiment of the present application, by selecting the solvent (for example, mixing ethanol and ethylenediamine at a volume ratio of 1:3), the (101) crystal plane can be developed in the electrode structure body, and thus the electrochemical characteristics (for example, redox reaction, oxygen evolution reaction, hydrogen evolution reaction) of the electrode structure body can be improved.

[0128] After mixing the above first precursor, the above second precursor, and the above third precursor in the above solvent, as shown in (a) of Figure 2 , nucleation and crystallization can be performed.

[0129] For example, the above first reducing agent can include at least one of ammonium hydroxide, ammonium chloride, or tetramethylammonium hydroxide.

[0130] The intermediate product including a plurality of stems can be prepared by co-precipitation of the above mixture including the above first precursor, the above second precursor, the above third precursor, the above first reducing agent, and the above solvent (step S130).

[0131] As shown in (b) of Figure 1 , the above mixture can form an intermediate product after heat treatment. The above intermediate product can have a plurality of stems, and the plurality of stems can form a network with each other.

[0132] For example, the above mixture to which the above first reducing agent is added can be washed using deionized water or ethanol after heat treatment by reflux at a temperature of 120°C.

[0133] During heat treatment, the above first reducing agent can maintain pH and increase reaction speed while functioning as a reducing agent. Thus, the above intermediate product having the above plurality of stems can be easily prepared. For example, in a case where the above transition metal is copper and the above chalcogen element is sulfur, the above intermediate structure can be CuPS having a copper blue crystal structure.

[0134] The fibrillated plurality of fibers including the above transition metal, the above chalcogen element, and phosphorus can be prepared by branching a plurality of branches from the above plurality of stems by a method of adding a second reducing agent to the above intermediate product and performing heat treatment under pressure (step S140).

[0135] According to an embodiment, the heat treatment under pressure process can be performed after adding the above intermediate product and the above second reducing agent to deionized water.

[0136] For example, the above second reducing agent can include at least one of Triton X-165, Triton X-102, Triton X-45, Triton X-114, Triton X-405, Triton X-101, trimesic acid, diamide, peroxynitrite, formaldehyde, thiomersal, or chloramine-T.

[0137] According to an embodiment, a chalcogen element supply source including the above chalcogen element can also be added together with the above second reducing agent. Thereby, the above chalcogen element lost during the reaction process can be supplemented by the above chalcogen element supply source, so that the above electrode structure having a sponge structure in which a plurality of fibrillated fibers form a network can be easily formed.

[0138] For example, in the case where the above-mentioned chalcogen is sulfur, the above-mentioned chalcogen supply source can include at least one of sodium bisulfite, sodium sulfate, sodium sulfide, sodium thiosulfate, sodium thiomethoxide, sodium ethanethiolate, or sodium methanethiolate.

[0139] The mixing of the above-mentioned intermediate product and the above-mentioned second reducing agent in deionized water can be performed in a cooled state. The reaction rate can be prevented from excessively increasing due to the heat generated during the addition of the above-mentioned second reducing agent, and thus the electrochemical characteristics of the above-mentioned electrode structure can be improved.

[0140] As described above, the second reducing agent is added to the above-mentioned intermediate product and is subjected to pressure and heat treatment, as shown in (c) of FIG. 1, and thus a plurality of branches can be branched from the above-mentioned plurality of trunks, and thus the above-mentioned electrode structure having a sponge structure in which a network of fibrillated fibers is formed can be formed. Figure 2

[0141] The above-mentioned electrode structure having a sponge structure can be immersed in liquid nitrogen after being washed using deionized water and ethanol. Thereby, the mechanical characteristics and flexibility of the above-mentioned electrode structure having a sponge structure can be improved.

[0142] Also, after being immersed in liquid nitrogen, the above-mentioned electrode structure having a sponge structure is freeze-dried to remove residual solvents, and thus a secondary reaction can be minimized.

[0143] As described above, the above-mentioned electrode structure can include a film having a sponge structure in which a network of fibrillated fibers of which a plurality of branches are branched from a plurality of trunks is formed. Thereby, the above-mentioned electrode structure can have a porous structure in which a plurality of pores having a size of 1 nm to 2 nm are provided, and has flexibility.

[0144] Also, as described above, by controlling the kind and ratio of the above-mentioned solvent mixed with the above-mentioned first precursor, the above-mentioned second precursor, and the above-mentioned third precursor, the (101) crystal plane can be developed in the above-mentioned electrode structure. Thereby, when the above-mentioned electrode structure is subjected to X-ray diffraction analysis, a peak value corresponding to the (101) crystal plane can have a maximum value compared to peak values corresponding to other crystal planes. When X-ray diffraction measurement is performed, the peak value corresponding to the (101) crystal plane can be observed in a range of 19° to 21° in a 2θ value.

[0145] ​The plurality of fibers constituting the electrode structure can include a compound of the transition metal, phosphorus, and the chalcogen element. For example, in a case where the transition metal is copper and the chalcogen element is oxygen, the fibers can be represented by the following Chemical Formula 1.

[0146] Chemical Formula 1

[0147] CuP x S y

[0148] In a case where the fibers constituting the electrode structure are represented by the above Chemical Formula 1, x + y = 1, 0.3 ≤ x ≤ 0.7, and 0.3 ≤ y ≤ 0.7 can be satisfied.

[0149] If x is less than 0.3 or greater than 0.7 and y is less than 0.3 or greater than 0.7 in the above Chemical Formula 1, the redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics of the electrode structure can be reduced, and thus the electrode structure can not be reversibly reacted in the charge and discharge process of a metal-air battery including the electrode structure as a positive electrode.

[0150] However, according to an embodiment of the present application, in a case where the electrode structure is represented by CuP x S y 0.3 or more and 0.7 or less. Thus, the redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics of the electrode structure can be improved, and the charge and discharge characteristics and life characteristics of a metal-air battery including the electrode structure as a positive electrode can be improved.

[0151] Alternatively, unlike the above, according to a modified example, the electrode structure can be a compound of the transition metal and the chalcogen element (for example, sulfur). Alternatively, according to another modified example, the electrode structure can be a compound of the transition metal and phosphorus.

[0152] In a case where the metal-air battery including the electrode structure as a positive electrode is charged and discharged, the lattice spacing of the fibers included in the electrode structure can be reversibly changed. Specifically, in a case where the metal-air battery is charged, the lattice spacing can be 0.478 nm, and in a case where the metal-air battery is discharged, the lattice spacing can be 0.466 nm. The lattice spacing of the fibers can be confirmed by a high-resolution transmission electron microscope.

[0153] According to the embodiment of the present application, the electrode structure having a film morphology formed of a network of the plurality of fibrillated fibers can be prepared by a method of co-precipitation and pressure heat treatment by mixing the first precursor having the above-mentioned chalcogen element, the second precursor having phosphorus, and the third precursor having the above-mentioned transition metal.

[0154] The electrode structure having high electrochemical characteristics can be prepared by an inexpensive method.

[0155] Further, the electrode structure is prepared by co-precipitation and pressure heat treatment, and thus the electrode structure for a positive electrode of a metal-air battery, which is easy to mass-produce and has a simple preparation process, can be provided.

[0156] Hereinafter, a metal-air battery including the electrode structure according to the embodiment of the present application will be described.

[0157] The metal-air battery can include a positive electrode, a negative electrode, and an electrolyte between the positive electrode and the negative electrode.

[0158] The negative electrode can include zinc. Alternatively, the negative electrode can include lithium.

[0159] The electrolyte can be a solid electrolyte. According to an embodiment, the electrolyte can be a membrane formed of a network of composite fibers including bacterial cellulose and dehydrated mannose acid bound to the bacterial cellulose, as described later. Alternatively, the electrolyte can be an oxide-based, sulfide-based, or polymer-based electrolyte.

[0160] The positive electrode can include the electrode structure described with reference to Figure 1 and Figure 2 and can use oxygen as a positive active material.

[0161] Hereinafter, the characteristics evaluation results of the electrode structure of the specific experimental example of the present application and the metal-air battery including the same will be described.

[0162] Preparation of the electrode structure body of Experimental Example 1 and the secondary battery

[0163] Dithioxamid was prepared as the first precursor having sulfur, a mixture (1:1, M%) of tetradecylphosphonic acid and isofosfamide was prepared as the second precursor having phosphorus, copper chloride was prepared as the third precursor having copper, and a mixture (1:3 v / v%) of ethanol and ethylenediamine was prepared as a solvent.

[0164] After the first to third precursors were added to the solvent, a suspension was prepared by stirring.

[0165] Then, 2.5M% of ammonium hydroxide was added as a first reducing agent, and after stirring for 2 hours, an intermediate product was obtained after heat treatment at a temperature of 120°C for 6 hours, and after washing with deionized water and ethanol, drying was performed in a vacuum at 50°C.

[0166] In an ice water bath, the intermediate product was mixed in 20ml of deionized water with Triton X-165 as a second reducing agent and sodium bisulfite as a supply source of sulfur element, and stirred. Then, a film formed of a compound of copper, phosphorus and sulfur and formed of a network of fibrillated fibers was prepared by pressure heat treatment at a temperature of 120°C for 24 hours.

[0167] The film was washed with deionized water and ethanol to adjust to neutral pH, and after storage at a temperature of -70°C for 2 hours, immersion in liquid nitrogen and freeze drying in a vacuum state, a CuPS electrode structure of Experimental Example 1 having a (101) crystal plane developed was prepared.

[0168] In the preparation of the electrode structure of Experimental Example 1, the ratio of the above first precursor having sulfur and the above second precursor having phosphorus was adjusted, and the ratio of P and S in CuPS was adjusted to 0.1:0.9, 0.2:0.8, 03:0.7, 0.5:0.5, 0.7:0.3 and 0.9:0.1, respectively.

[0169] The CuPS electrode structure of Experimental Example 1 was used as a positive electrode, and a solid electrolyte of a later-described Experimental Example and a patterned zinc negative electrode were stacked to prepare a zinc-air battery of Experimental Example 1.

[0170] Preparation of the electrode structure body of Experimental Example 2

[0171] The same method as Experimental Example 1 above was performed, but a mixture of ethanol and toluene (1:1 v / v%) was used as a solvent, and pressure heat treatment was performed at a temperature of 150°C for 24 hours to prepare a CuPS electrode structure of Experimental Example 2.

[0172] In the preparation of the electrode structure of Experimental Example 1, the ratio of the above first precursor having sulfur and the above second precursor having phosphorus was adjusted, and the ratio of P and S in CuPS was adjusted to 0.1:0.9, 0.2:0.8, 03:0.7, 0.5:0.5, 0.7:0.3 and 0.9:0.1, respectively.

[0173] Preparation of the electrode structure body of Experimental Example 3

[0174] The same method as Experimental Example 2 above was performed, but the second precursor having phosphorus was omitted to prepare a CuS electrode structure of Experimental Example 3.

[0175] Preparation of the electrode structure body of Experimental Example 4

[0176] The same method as in Experimental Example 2 above was performed, but the first precursor having sulfur was omitted to prepare the CP electrode structure of Experimental Example 4.

[0177] Preparation of the solid electrolyte according to the experimental example

[0178] Acetobacter xylinum was prepared as a bacterial strain, and a chitosan derivative was prepared. The chitosan derivative was prepared by treating a suspension in which 1 g of chitosan chloride was dissolved in 1% (v / v) aqueous acetic acid at a temperature of 65°C under a nitrogen (N2) atmosphere with 1M glycidyltrimethylammonium chloride for 24 hours, and then precipitating and filtering with ethanol several times.

[0179] A Hestrin-Schramm (HS) medium containing 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 chitosan derivative (2% w / v) was prepared, and was steam sterilized at a temperature of 121°C for 20 minutes. Also, after activating the Acetobacter xylinum in the pre-cultivation Hestrin-Schramm (HS) medium at a temperature of 30°C for 24 hours, acetic acid was added to maintain a pH of 6.

[0180] Then, the Acetobacter xylinum was cultured in the Hestrin-Schramm (HS) medium at a temperature of 30°C for 7 days.

[0181] The harvested bacterial pellicle was washed with deionized water to neutralize the pH of the supernatant, and was dehydrated in a vacuum at 105°C. After demineralizing the cellulose with 1N HCl for 30 minutes (mass ratio 1:15, w / v) to remove excess reagents, the bacterial pellicle was centrifuged and purified several times with deionized water until the supernatant reached a neutral pH. Finally, the base composite fiber (chitosan-bacterial cellulose (CBC)) was prepared after evaporating all solvents at a temperature of 100°C.

[0182] 2 g of the base composite fiber dispersed in a 2mM aqueous solution of tetramethylpiperidine oxide (TEMPO) was reacted with NaBr (1.9mM). 5mM NaClO was used as an oxidizing agent.

[0183] The suspension was stirred using ultrasonic waves and the reaction was allowed to proceed for 3 hours at room temperature. The pH of the suspension was maintained at 10 by continuously adding a 0.5 M NaOH solution. Next, 1 N HCl was added to the suspension to maintain the pH at neutral for 3 hours. The oxidized slurry formed in the suspension was washed 3 times using 0.5 N HCl and the pH of the supernatant was brought to neutral using deionized water.

[0184] The washed slurry was stirred using acetone, toluene for 30 minutes to evaporate the solvent and finally, the first composite fiber (oCBC) fiber was obtained.

[0185] 1 g of the base composite fiber dispersed in a solution of N,N-dimethylacetamide (35 ml) was reacted with a LiBr (1.25 g) suspension for 30 minutes. N-bromosuccinimide (2.1 g) and triphenylphosphine (3.2 g) were used as coupling agents. After stirring the two reaction mixtures for 10 minutes, the reaction was carried out at a temperature of 80°C for 60 minutes.

[0186] Next, after cooling the reaction suspension at room temperature, deionized water was added, filtered, rinsed using deionized water and ethanol, and freeze-dried to obtain the brominated base composite fiber (bCBC) fiber.

[0187] The brominated base composite fiber was dissolved in 100 ml of N,N-dimethylformamide and reacted with 1.2 g of 1,4-diazabicyclooctane coupling agent.

[0188] Then, the mixture was treated using ultrasonic waves for 30 minutes and the reaction was allowed to proceed for 24 hours at room temperature. The molten solution formed was mixed with diethyl ether, washed 5 times using diethyl ether / ethyl acetate, and freeze-dried to obtain the second composite fiber (covalently quaternized CBC, qCBC).

[0189] The first composite fiber (oCBC) and the second composite fiber (qCBC) were dissolved in a mixture of methylene chloride, 1,2-propanediol, and acetone (8:1:1 v / v / v%) using ultrasonic waves at the same weight ratio, and 1 weight percent of glutaraldehyde as a cross-linking agent and 0.3 weight percent of N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethanesulfonyl) imide as an initiator were added.

[0190] The bubbles of the gel suspension were removed using a vacuum chamber (200 Pa) and cast on a glass at a temperature of 60°C for 6 hours. The composite fiber membrane was coagulated and peeled off using deionized water and vacuum-dried after washing with deionized water.

[0191] The solid electrolyte (CBCs) were prepared by ion exchange using 1M aqueous KOH and 0.1M ZnTFSI at room temperature for 6 hours, respectively. After that, in order to prevent reaction with CO2 and formation of carbonate, the process of washing and precipitation using deionized water was performed under a nitrogen atmosphere.

[0192] Figure 3 To photograph the stress-strain curve of the electrode structure prepared according to Experimental Example 1 of the present application, Figure 4 To photograph the stress-strain curve of the electrode structure prepared according to Experimental Example 1 of the present application.

[0193] Referring to Figure 3 and Figure 4 , the electrode structure (CuP 0.5 S 0.5 ) prepared according to Experimental Example 1 was photographed, and the strain according to the stress was measured at a relative humidity of about 40% and room temperature.

[0194] As shown in Figure 3 , it can be confirmed that the electrode structure of Experimental Example 1 has a length of about 10 cm and has flexibility.

[0195] Also, as shown in Figure 4 , it still has a high recovery rate of about 94% after applying a stress of 1000 times, and it can be confirmed that the electrode structure of Experimental Example 1 has high flexibility, compressibility, and elasticity.

[0196] Figure 5 To photograph the stress-strain curve of the electrode structure prepared according to Experimental Example 1 of the present application, Figure 6X-ray diffraction curve of the electrode structure prepared according to Experimental Example 2 of the present application, Figure 7 X-ray diffraction curve of the electrode structure prepared according to Experimental Example 3 of the present application, Figure 8 X-ray diffraction curve of the electrode structure prepared according to Experimental Example 4 of the present application.

[0197] Referring to Figure 5 to Figure 8 , the CuPS electrode structures according to Experimental Example 1 having various composition ratios of P and S, the CuPS electrode structures according to Experimental Example 2 having various composition ratios of P and S, the CS and CP electrode structures of Experimental Examples 3 and 4 were subjected to X-ray diffraction measurement.

[0198] It can be confirmed from Figure 5 and Figure 6 that in the CuPS electrode structures of Experimental Examples 1 and 2, it can be confirmed that the pattern varies depending on the composition ratio of P and S, and it can be known that the peak size corresponding to the (101) crystal plane is larger than that of the peak corresponding to other crystal planes.

[0199] Also, in the case of the CuPS electrode structure of Experimental Example 1 in which the (101) crystal plane is developed, it can be confirmed that the size of the peak corresponding to the (101) crystal plane is significantly higher than that of the peak corresponding to other crystal planes other than the (101) crystal plane, compared to the CuPS electrode structure of Experimental Example 2 of Figure 6

[0200] It can be known from Figure 7 and Figure 8 that in the cases of the CuS and CuP electrode structures of Experimental Examples 3 and 4, unlike the CuPS electrode structures of Experimental Examples 1 and 2, the peak corresponding to the (101) crystal plane is not large, or the peak corresponding to the (101) crystal plane is not observed.

[0201] Also, it can be known that the CuPS electrode structures of Experimental Examples 1 and 2 have a covellite phase as an orthorhombic crystal structure Pnm21 space group, and it can be confirmed that the CuS electrode structure of Experimental Example 3 has a hexagonal crystal structure P63 / mmc space group, and the CuP electrode structure of Experimental Example 4 has a hexagonal crystal structure P63cm space group.

[0202] Figure 9 A scanning electron microscope image of the electrode structure of Experimental Example 1 of the present application, Figure 10 A transmission electron microscope image of the electrode structure of Experimental Example 1 of the present application, Figure 11 An atomic structure simulation image and a lattice fringe of the electrode structure of Experimental Example 1 of the present application.​

[0203] Referring to Figure 9 to Figure 11 , a scanning electron microscope image and a transmission electron microscope image of the CuPS electrode structure (CuP 0.5 S 0.5 ) of Experimental Example 1 were taken, and a simulation image of atomic structure and a lattice fringe were shown. Figure 10 The (a) part of FIG. 6 is a high-resolution (scale: 2 nm) transmission electron microscope image of the electrode structure of Experimental Example 1, Figure 10 The (b) part of FIG. 6 is a low-resolution (scale: 30 nm) transmission electron microscope image of the electrode structure of Experimental Example 1, Figure 11 The (a) part of FIG. 7 is a graph showing atomic arrangement of the (101) plane of the electrode structure of Experimental Example 1, Figure 11 The (b) part of FIG. 7 is a topographic plot profile of the lattice fringe of the electrode structure of Experimental Example 1.

[0204] As can be seen from Figure 9 , it can be confirmed that the electrode structure of Experimental Example 1 is composed of a network of a plurality of fibers.

[0205] Also, as can be seen from Figure 10 and Figure 11 , it can be confirmed that the lattice spacing of the electrode structure of Experimental Example 1 is 0.466 nm.

[0206] Figure 12 FIG. 8 is a selected area electron diffraction pattern of the electrode structure of Experimental Example 1 of the present application, Figure 13 FIG. 9 is a high-angle annular dark field-scanning transmission electron microscope image of the electrode structure of Experimental Example 1 of the present application.

[0207] Referring to Figure 12 and Figure 13 , a selected area electron diffraction pattern (scale: 2 nm -1 ) of the (101) plane of the CuPS electrode structure (CuP 0.5 S 0.5 ) of Experimental Example 1 was obtained, a high-angle annular dark field scanning transmission electron microscope (HAADF-STEM) image was taken, and results of mapping Cu, P and S were shown.

[0208] As can be seen from Figure 12 and Figure 13 , the electrode structure of Experimental Example 1 is an orthorhombic crystal structure having a (101) plane, and is formed of a compound of Cu, P and S.

[0209] Figure 14 A graph for illustrating the specific surface area and the pore of the electrode structure of Experimental Example 1 of the present application.

[0210] Referring to Figure 14 , the BET surface area of the CuPS electrode structure (CuP 0.5 S 0.5 ) of Experimental Example 1 described above was measured. It can be confirmed that the specific surface area of the electrode structure of Experimental Example 1 is 1168 m 2 / g, has a porous structure, and has a large number of pores of 1 nm to 2 nm in size.

[0211] Figure 15 A graph for the measurement of X-ray photoelectron spectroscopy of the electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4 of the present application.

[0212] Referring to Figure 15 , the measurement of X-ray photoelectron spectroscopy was performed on the electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4, and the ratios of Cu, P, and S of the electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4 were calculated. Also, the ratios of Cu, P, and S of the electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4 calculated by inductively coupled plasma (ICP) and energy dispersive X-ray spectroscopy (EDS) are shown in Tables 1 to 3 below.

[0213] Table 1

[0214]

[0215] Table 2

[0216]

[0217] Table 3

[0218]

[0219] From Tables 1 to 3, it can be confirmed that the ratios of Cu, P, and S of the electrode structure of Experimental Example 1 are substantially 1:0.5:0.5, the ratios of Cu and S of the electrode structure of Experimental Example 3 are substantially 1:1, and the ratios of Cu and P of the electrode structure of Experimental Example 4 are substantially 3:1.

[0220] Figure 16 A graph for the measurement of extended X-ray absorption fine structure (EXAFS) k 2 χ(k) R-space Fourier transform of the electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4 and a copper foil. Figure 17Cu 2p X-ray photoelectron spectroscopy spectrum of the electrode structure of Experimental Example 1, Experimental Example 3, and Experimental Example 4, Figure 18 Cu L-edge X-ray absorption near-edge structure (XANES) spectroscopy spectrum of the electrode structure of Experimental Example 1, Experimental Example 3, and Experimental Example 4, Figure 19 Cu K-edge X-ray absorption near-edge structure spectroscopy spectrum of the electrode structure of Experimental Example 1, Experimental Example 3, and Experimental Example 4, and a copper foil.

[0221] Referring to Figure 16 , EXAFS k 2 χ(k) R-space Fourier transform of the electrode structure of Experimental Example 1, Experimental Example 3, and Experimental Example 4, and the electrode structure of Experimental Example 1 subjected to 30,000 cycles of charge and discharge. 0.5 S 0.5 of the electrode structure of Experimental Example 1.

[0222] From Figure 16 it can be seen that, in the case of the electrode structure of Experimental Example 1, 1 / 2 S-Cu-1 / 2 P bonding is present, and a copper blue crystal structure is present, and even after 30,000 cycles, the structure remains essentially constant without structural change. Also, in the case of the electrode structure of Experimental Example 3, Cu-S bonding can be confirmed, and in the case of the electrode structure of Experimental Example 4, Cu-P bonding can be confirmed.

[0223] Referring to Figure 17 , Cu 2p X-ray photoelectron spectroscopy measurements were performed on the electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4, and the electrode structure of Experimental Example 1 subjected to 30,000 cycles of charge and discharge, referring to Figure 18 Cu L-edge X-ray absorption near-edge structure measurements were performed on the electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4, referring to Figure 19 Cu K-edge X-ray absorption near-edge structure measurements were performed on the electrode structures of Experimental Example 1, Experimental Example 3, and Experimental Example 4, and a copper foil.

[0224] From Figure 17 and Figure 18 it can be seen that Cu 2p 3 / 2 and Cu 2p 1 / 2 2p to 3d 9 characteristic transitions can be confirmed from 930.9 eV and 950.8 eV, which corresponds to about 8986 eV of Figure 19 , and as a result, it can be seen that the C(II) oxidation number is dominant.

[0225] Also, in Figure 17 andFigure 18 In Experiment 4, the peak of the CP electrode structure shifted to the right by approximately 2.8 eV, exhibiting a 3d shift towards Cu(I). 10 State transitions. Furthermore, lattices deformed like the electrode structure in Example 1 can hybridize Cu 3d and S 2p to facilitate electron transfer from Cu 3d to S 2p.

[0226] Figure 20 These are the SK-edge X-ray absorption near-edge structure spectra of the electrode structures in Experimental Examples 1 and 3 of this application. Figure 21 These are the SL-edge X-ray absorption near-edge structure spectra of the electrode structures in Experimental Examples 1 and 3 of this application. Figure 22 The image shows the S 2p X-ray photoelectron spectroscopy curves of the electrode structures in Experimental Examples 1 and 3 of this application.

[0227] Reference Figure 20 to Figure 22 The SK-edge X-ray absorption near-edge structure spectra and SL-edge X-ray absorption near-edge structure spectra of the electrode structures of Experimental Example 1 and Experimental Example 3 were measured. The S 2p X-ray photoelectron spectroscopy spectra of the electrode structures of Experimental Example 1 and Experimental Example 3, as well as the electrode structure of Experimental Example 1 after 30,000 cycles, were also measured. CuP was used. 0.5 S 0.5 The electrode structure used in Experiment Example 1.

[0228] like Figure 20 As shown, in the case of the electrode structure in Experimental Example 1, a pre-edge was identified at approximately 2471 eV, and a broad-edge was identified at approximately 2477 eV. This indicates that S 2- State.

[0229] like Figure 22 As shown, it can be confirmed that the electrode structure of Experimental Example 1 retains essentially the same structure after 30,000 charge-discharge cycles. This indicates that the electrons in S 2p3 / 2 and S 2p1 / 3 no longer correspond to SL. 3,2 - The antibonding state of electrons at the edge is transferred to the spin-orbit.

[0230] Figure 23 These are the P K-edge X-ray absorption near-edge structure spectra of the electrode structures in Experimental Examples 1 and 4 of this application. Figure 24 These are the PL-edge X-ray absorption near-edge structure spectra of the electrode structures in Experimental Examples 1 and 4 of this application. Figure 25A P 2p X-ray photoelectron spectroscopy spectrum of the electrode structure of Experimental Example 1 and Experimental Example 3.

[0231] Referring to Figure 23 to Figure 25 , a P K-edge X-ray absorption near-edge structure spectrum and a P L-edge X-ray absorption near-edge structure spectrum of the electrode structure of Experimental Example 1 and Experimental Example 4 were measured, and a P 2p X-ray photoelectron spectroscopy spectrum of the electrode structure of Experimental Example 1 and Experimental Example 4 and the electrode structure of Experimental Example 1 subjected to 30,000 charge-discharge cycles was measured.

[0232] As shown in Figure 23 to Figure 25 , X-rays were absorbed at 2144.2 eV and 2152.6 eV, which indicates a critical electron transfer to an unfilled electron d orbital in a P 2p state, and spin-orbit splitting of P 2p3 / 2 and P 2p1 / 2 occurred at about 129 eV and about 129.8 eV.

[0233] Figure 26 A thermogravimetric analysis (TGA) measurement result of the electrode structure of Experimental Example 1.

[0234] Referring to Figure 26 , a thermogravimetric analysis was performed on the CuPS electrode structure (CuP 0.5 S 0.5 ) of Experimental Example 1 while being heated to 5°C in a nitrogen and air atmosphere.

[0235] As can be seen from Figure 26 , the electrode structure of Experimental Example 1 was stable at a high temperature. Weight loss occurred in a temperature range of 605°C to 732°C in a nitrogen atmosphere, and weight loss occurred in a temperature range of 565°C to 675°C in an air atmosphere. It can be seen that the electrode structure of Experimental Example 1 is slightly more stable in a nitrogen atmosphere than in an air atmosphere, because CuO is formed in the electrode structure of Experimental Example 1.

[0236] In summary, it can be confirmed that the electrode structure of Experimental Example 1 has high thermal stability of an orthorhombic crystal structure.

[0237] Figure 27 A cyclic voltammogram for explaining redox reaction characteristics of the electrode structure of Experimental Example 1 and Experimental Example 2, Figure 28 A cyclic voltammogram for explaining redox reaction characteristics of the electrode structure of Experimental Example 3 and Experimental Example 4 and a Pt / C electrode.

[0238] Referring to Figure 27 and Figure 28, the cyclic current-voltage curves of the electrode structures of Experimental Examples 1 to 4 and a commercially available Pt / C electrode (20 weight percent) were measured using 0.1 M KOH as an electrolyte. CuP 0.5 S 0.5 The electrode structures of Experimental Examples 1 and 2. In Figure 27 and Figure 28 The dotted line indicates a nitrogen-saturated condition, and the solid line indicates an oxygen-saturated condition.

[0239] From Figure 27 and Figure 28 It can be confirmed that the oxygen reduction potential of the electrode structures of Experimental Examples 1 to 4 has excellent redox reaction characteristics compared to the commercialized Pt / C electrode.

[0240] Figure 29 is a linear sweep voltammetry curve for explaining the redox reaction characteristics of the electrode structures of Experimental Examples 1 to 4 of the present application, a Pt / C electrode, and carbon fiber, Figure 30 is a rotating ring-disk electrode polarization graph and an electron transfer number curve of the electrode structures of Experimental Examples 1 to 4 of the present application and a Pt / C electrode.

[0241] Referring to Figure 29 to Figure 30 , the redox reaction characteristics of the electrode structures of Experimental Examples 1 to 4, a commercially available Pt / C electrode, and a commercially available carbon fiber were compared. CuP 0.5 S 0.5 The electrode structures of Experimental Examples 1 and 2. Also, the rotating ring-disk electrode polarization curve and the electron transfer number of the electrode structures of Experimental Examples 1 to 4 and a Pt / C electrode are shown, and the OH2- yield of the electrode structure of Experimental Example 1 is shown.

[0242] From Figure 29 It can be confirmed that the redox reaction characteristics of the CuPS electrode structure in which the (101) crystal plane is enhanced according to Experimental Example 1 are the best, and the electron transfer number value is the highest. Also, it can be confirmed that the redox reaction characteristics of the CuPS electrode structure of Experimental Example 2 and the CuS electrode structure of Experimental Example 3 are slightly lower than those of the commercially available Pt / C, but still have excellent redox reaction characteristics.

[0243] In summary, it can be confirmed that by using the electrode structures of Experimental Examples 1 to 3 of the present application, an electrode structure having similar redox reaction characteristics to Pt / C or higher redox reaction characteristics than Pt / C can be prepared at a lower price than Pt / C.

[0244] Figure 31 is a curve graph for comparing the chemical durability of the electrode structure of Experimental Example 1 of the present application and a Pt / C electrode.

[0245] Reference Figure 31 Chemical durability was measured by injecting methanol (2M) and CO2 (10V%) into the electrode structure of Experimental Example 1 and a commercially available Pt / C electrode using 0.1M KOH at 1600 rpm. CuP was used. 0.5 S 0.5 The electrode structure used in Experiment Example 1.

[0246] like Figure 31 As shown, in the case of the electrode structure in Experimental Example 1, it can be confirmed that the current remains stably driven after the injection of methanol and CO2. Conversely, in the case of the Pt / C electrode, it can be confirmed that the current value decreases significantly when methanol or CO2 is injected.

[0247] In summary, it can be seen that the CuPS electrode structure of Experimental Example 1 of this application not only has high redox reaction characteristics but also excellent chemical resistance compared with commercially available Pt / C electrodes. Therefore, it can be concluded that the CuPS electrode structure of Experimental Example 1 of this application can be used stably in alkaline environments.

[0248] Figure 32 Electrochemical impedance spectroscopy curves are used to illustrate the redox reaction characteristics of the electrode structures and carbon fibers in Experimental Examples 1, 3 and 4 of this application.

[0249] Reference Figure 32 Electrochemical impedance spectroscopy was performed on the electrode structures and carbon fibers of Experiments 1, 3, and 4 using 0.1 M KOH. CuP was used. 0.5 S 0.5 The electrode structure used in Experiment Example 1.

[0250] from Figure 32 It can be confirmed that the CuPS electrode structure of Experimental Example 1 has the lowest impedance value, and the redox reaction characteristics from high to low are CuPS electrode structure of Experimental Example 1, CuS electrode structure of Experimental Example 3, CP electrode structure of Experimental Example 4, and carbon fiber.

[0251] Figure 33 To illustrate the redox reaction characteristics of the electrode structure in Experimental Example 1 of this application, a linear sweep voltammetry method based on the number of cycles and a cyclic voltammetry curve were used. Figure 34 Linear sweep voltammetry and cyclic voltammetry curves for Pt / C electrodes based on the number of cycles. Figure 35 Chronoamperometry measurement curves and Faraday efficiency measurement results are used to illustrate the redox reaction characteristics of the electrode structure and Pt / C electrode in Experimental Example 1 of this application.

[0252] ReferenceFigure 33 to Figure 35 The CuPS electrode structure of Experimental Example 1 and a commercially available Pt / C electrode were measured using linear sweep voltammetry (LSV) and cyclic voltammetry based on the number of cycles under oxygen conditions with 0.1M KOH. Furthermore, the Faraday efficiency of the CuPS electrode structure and Pt / C electrode of Experimental Example 1 was measured using chronoamperometry at 0.9V. Using CuP… 0.5 S 0.5 The electrode structure used in Experiment Example 1.

[0253] from Figure 33 to Figure 35 It can be confirmed that the electrode structure of Experimental Example 1 remains stably driven without substantial change after 30,000 charge-discharge cycles. Furthermore, it can be confirmed that it remains stably driven without substantial change for 500 hours, exhibiting a Faraday efficiency of over 98%.

[0254] Conversely, in the case of the Pt / C electrode, the current density value decreased significantly with cycling, and the characteristics were significantly reduced compared to the electrode structure of Experimental Example 1.

[0255] In summary, it can be seen that the CuPS electrode structure in Experimental Example 1 not only has high redox reaction characteristics and excellent chemical resistance, but also has a long lifespan compared with commercial Pt / C electrodes.

[0256] Figure 36 Gas chromatography measurement results are used to illustrate the oxygen evolution reaction characteristics of the electrode structure in Experimental Example 1 of this application.

[0257] Reference Figure 36 Gas chromatography was used to measure the CuPS electrode structure of Experimental Example 1 under oxygen conditions with 0.1M KOH. CuPS... 0.5 S 0.5 The electrode structure used in Experiment Example 1.

[0258] from Figure 36 It can be confirmed that oxygen is generated on the surface of the CuPS electrode structure in Experimental Example 1.

[0259] Figure 37 Linear sweep voltammetry curves and Tafel curves are used to illustrate the oxygen evolution reaction characteristics of the electrode structures, carbon fibers, and RuO2 electrodes in Experimental Examples 1 to 4 of this application. Figure 38 Electrochemical impedance spectroscopy curves are used to illustrate Experimental Examples 1, 3, and 4 of this application and the oxygen evolution reaction characteristics of carbon fibers.

[0260] Reference Figure 37 and Figure 38, the linear sweep voltammetry measurement of the electrode structure, carbon fiber and RuO2 electrode of Experimental Example 1 to Experimental Example 4 was performed, and the Tafel value was shown. Also, the electrochemical impedance measurement of the electrode structure and carbon fiber of Experimental Example 1, Experimental Example 3 and Experimental Example 4 was performed. CuP 0.5 S 0.5 As the electrode structure of Experimental Example 1 and Experimental Example 2.

[0261] From Figure 37 and Figure 38 , it can be confirmed that the oxygen evolution reaction characteristics from high to low are the CuPS electrode structure of Experimental Example 1, the RuO2 electrode, the CuPS electrode structure of Experimental Example 2, the CP electrode structure of Experimental Example 4, the CuS electrode structure of Experimental Example 3 and the carbon fiber. In particular, it can be confirmed that the CuPS electrode structure of Experimental Example 1 has the lowest overpotential value of 260 mV at 10 mAcm -2 -2, and the Tafel curve is 58 mVdec -1 , which is significantly higher than the commercial RuO2.

[0262] Figure 39 is a linear sweep voltammetry curve according to the number of cycles for explaining the oxygen evolution reaction characteristics of the electrode structure and RuO2 electrode of Experimental Example 1 of the present application, Figure 40 is a chronoamperometry measurement curve and Faraday efficiency measurement result for explaining the oxygen evolution reaction characteristics of the electrode structure and RuO2 electrode of Experimental Example 1 of the present application.

[0263] Referring to Figure 39 and Figure 40 , the linear sweep voltammetry measurement according to the number of cycles of the CuPS electrode structure of Experimental Example 1 and the commercially available RuO2 electrode was performed using 0.1 M of KOH at 1600 rpm. Also, the CuPS electrode structure of Experimental Example 1 and the RuO2 electrode were measured using chronoamperometry at 1.5 V, and the Faraday efficiency of the CuPS electrode of Experimental Example 1 was measured. CuP 0.5 S 0.5 As the electrode structure of Experimental Example 1.

[0264] From Figure 39 and Figure 40 , it can be confirmed that the electrode structure of Experimental Example 1 is stably driven without substantial change even after 30,000 times of charge and discharge cycles. Also, it can be confirmed that it is stably driven without substantial change for about 500 hours, and has a Faraday efficiency of about 99% or more.

[0265] On the contrary, in the case of the RuO2 electrode, it was confirmed that the overpotential sharply increased and the current density value sharply decreased as the cycle progressed, and a loss of 85% occurred after 24 hours.

[0266] In summary, it was known that the CuPS electrode structure of Experimental Example 1 had not only high oxygen evolution reaction characteristics but also long life compared to the commercial RuO2 electrode.

[0267] Figure 41 FIG. 1 is a graph for explaining the bifunctional oxygen characteristics of the electrode structure of Experimental Example 1 to Experimental Example 4 of the present application, a Pt / C electrode, a RuO2 electrode, and carbon fiber, Figure 42 FIG. 2 is a graph for comparing the bifunctional oxygen characteristics of the electrode structure of Experimental Example 1 of the present application with other electrodes reported so far.

[0268] Referring to Figure 41 and Figure 42 , the oxidation-reduction reaction and the oxygen evolution reaction characteristics of the electrode structure of Experimental Example 1 to Experimental Example 4, a Pt / C electrode, a RuO2 electrode, and carbon fiber were compared. CuPS 0.5 S 0.5 was used as the electrode structure of Experimental Example 1 and Experimental Example 2. The bifunctional reaction of reversible oxygen was determined by the difference (ΔE) in the overpotential of the oxidation-reduction reaction and the oxygen evolution reaction, and the greater the difference, the higher the reversibility.

[0269] As shown in Figure 41 , it was confirmed that in the case of the electrode structure of Experimental Example 1, the difference in the overpotential of the oxidation-reduction reaction and the oxygen evolution reaction was 0.59 V, and had excellent reversibility compared to the Pt / C electrode and the RuO2 electrode.

[0270] Also, as shown in Figure 42 , it was confirmed that in the case of the electrode structure of Experimental Example 1, the difference in the overpotential of the oxidation-reduction reaction and the oxygen evolution reaction was the lowest compared to other electrodes reported so far, and had excellent reversibility for the oxygen evolution reaction and the oxidation-reduction reaction.

[0271] Figure 43 FIG. 3 is a linear sweep voltammetry graph for explaining the hydrogen evolution reaction characteristics of Experimental Example 1 to Experimental Example 4 of the present application, a Pt / C electrode, and carbon fiber, Figure 44 FIG. 4 is a chronoamperometry measurement graph for explaining the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 of the present application and a Pt / C electrode, Figure 45 FIG. 5 is a Tafel curve for explaining the hydrogen evolution reaction characteristics of Experimental Example 1 to Experimental Example 4 of the present application, a Pt / C electrode, and carbon fiber.

[0272] Referring to Figure 43 to Figure 45, the linear sweep voltammetry measurement of the electrode structure of Experimental Example 1 to Experimental Example 4, carbon fiber and Pt / C electrode was carried out, and the Tafel value was shown. And, the electrode structure of Experimental Example 1 and Pt / C electrode were measured by chronopotentiometry. CuP 0.5 S 0.5 As the electrode structure of Experimental Example 1 and Experimental Example 2.

[0273] From Figure 43 to Figure 45 It can be seen that the excellent hydrogen evolution reaction characteristics are in turn the electrode structure of Experimental Example 1, Pt / C electrode, the electrode structure of Experimental Example 2, the electrode structure of Experimental Example 4, the electrode structure of Experimental Example 3 and carbon fiber.

[0274] Especially, it can be confirmed that the CuPS electrode structure of Experimental Example 1 has high hydrogen evolution reaction characteristics compared with the commercial Pt / C electrode. Especially, the Tafel value of the electrode structure of Experimental Example 1 is 20mVdec -1 , which is lower than the Tafel value (30mVdec -1 ) of Pt / C electrode, which indicates that the electrode structure of Experimental Example 1 carries out the hydrogen evolution reaction process in Volmer-Tafel mechanism.

[0275] Figure 46 The linear sweep voltammetry curve according to the number of cycles for illustrating the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 and Pt / C electrode of the present application is shown.

[0276] Referring to Figure 46 , the linear sweep voltammetry measurement according to the number of cycles was carried out on the CuPS electrode structure of Experimental Example 1 and Pt / C electrode.

[0277] From Figure 46 It can be seen that it can be confirmed that in the case of Pt / C electrode, after 20000 cycles, the overpotential increases greatly and the hydrogen evolution reaction characteristics decrease sharply. On the contrary, it can be confirmed that the electrode structure of Experimental Example 1 still drives stably without substantial change after 30000 cycles.

[0278] In summary, it can be seen that the CuPS electrode structure of Experimental Example 1 not only has high hydrogen evolution reaction characteristics, but also has long service life compared with the commercial Pt / C electrode.

[0279] Figure 47 The curve for comparing the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 of the present application and other electrodes reported so far is shown.

[0280] Referring to Figure 47 , it can be confirmed that the electrode structure of Experimental Example 1 (CuP 0.5 S 0.5), the overpotential value is small compared with other electrodes reported so far, and thus it can be confirmed that the electrode structure of Experimental Example 1 can achieve high hydrogen evolution reaction characteristics without using an expensive noble metal.

[0281] Figure 48 Fig. 2 is a linear sweep voltammetry curve diagram for explaining the redox reaction characteristics of the electrode structure of Experimental Example 1 and a Pt / C electrode in an acidic environment, Figure 49 Fig. 3 is a linear sweep voltammetry curve diagram for explaining the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 and a Pt / C electrode in an acidic environment, Figure 50 Fig. 4 is a curve diagram for comparing the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 and other electrodes reported so far in an acidic environment.

[0282] Referring to Figure 48 and Figure 49 , linear sweep voltammetry measurements of the electrode structure of Experimental Example 1 and a Pt / C electrode were performed using 0.1 M HC104 to confirm the redox reaction characteristics. Also, the hydrogen evolution reaction characteristics of the electrode structure of Experimental Example 1 and other electrodes reported so far were compared in a 0.5 M H2SO4 environment. CuP 0.5 S 0.5 was used as the electrode structure of Experimental Example 1.

[0283] As can be seen from Figure 48 , the electrode structure of Experimental Example 1 was stably driven in an acidic environment, and even after 10,000 cycles, there was no substantial change in the redox reaction characteristics. In contrast, it can be seen that the Pt / C electrode had a decrease in the redox reaction characteristics due to a sharp increase in overpotential after 10,000 cycles in an acidic environment.

[0284] Also, as can be seen from Figure 49 , it can be confirmed that the electrode structure of Experimental Example 1 had a slight increase in overpotential after 20,000 cycles, and still stably maintained the hydrogen evolution reaction characteristics in an acidic environment, but in the case of the Pt / C electrode, the hydrogen evolution reaction characteristics were reduced due to a significant increase in overpotential after 20,000 cycles.

[0285] Also, as can be seen from Figure 50 , it can be confirmed that the electrode structure of Experimental Example 1 can still maintain high hydrogen evolution reaction characteristics in an acidic environment compared with other electrodes reported so far.

[0286] Figure 51 Fig. 5 is a mass activity for comparing the redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics of the electrode structures of Experimental Examples 1 and 2, a Pt / C electrode, and a RuO2 electrode.

[0287] Reference Figure 51 Mass activity was calculated in the redox reactions, oxygen evolution reactions, and hydrogen evolution reactions of the electrode structures, Pt / C electrodes, and RuO2 electrodes in Experimental Examples 1 and 2. CuP was used. 0.5 S 0.5 As the electrode structure of Experimental Example 1 and Experimental Example 2.

[0288] like Figure 51 As shown, it can be confirmed that the electrode structures of Experimental Example 1 and Experimental Example 2 have higher mass activity compared with Pt / C electrode and RuO2 electrode in redox reaction, oxygen evolution reaction and hydrogen evolution reaction.

[0289] In particular, in the case of the electrode structure in Experimental Example 1, the mass activity value remained unchanged after 30,000 cycles.

[0290] In summary, it can be confirmed that the electrode structures of Experimental Example 1 and Experimental Example 2 have higher redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics compared with commercially available Pt / C and RuO2.

[0291] Figure 52 This is an in-situ X-ray diffraction measurement curve of the electrode structure of Experimental Example 1 under the charge and discharge states of the secondary battery in Experimental Example 1 of this application. Figure 53 This is a high-resolution transmission electron microscope image of the electrode structure of Experimental Example 1, taken under the charge and discharge conditions of the secondary battery in Experimental Example 1 of this application.

[0292] Reference Figure 52 and Figure 53 In-situ X-ray diffraction measurements of the electrode structure of Experimental Example 1 were performed under the charge-discharge conditions of the secondary battery in Experimental Example 1, simultaneously showing the galvanostatic charge-discharge curves and the volume change of the unit cell of the electrode structure of Experimental Example 1. Furthermore, high-resolution transmission electron microscopy images of the electrode structure of Experimental Example 1 were simultaneously taken under the charge-discharge conditions of the secondary battery in Experimental Example 1.

[0293] from Figure 52 and Figure 53 It can be seen that the electrode structure of Experimental Example 1 exhibits a peak in the range of 18.5° to 19.5° with a 2θ value. As charging proceeds under discharge conditions, the corresponding 2θ value shifts to the left and decreases, resulting in the peak splitting into two. Furthermore, when using a 2.2V buffer, it can be confirmed that the lattice spacing increases from 0.466 nm to 0.478 nm, and the cell volume increases from... Increase to That is, it was found that the electrode structure of Experimental Example 1 had undergone a solid-solution reaction while maintaining the orthorhombic crystal structure during the charge and discharge.

[0294] Figure 54 Fig. 2 is a Cu K-edge X-ray absorption near-edge structure spectrum of the electrode structure of Experimental Example 1 under the charge and discharge state of the secondary battery of Experimental Example 1, Figure 55 Fig. 3 is an S K-edge and P L-edge X-ray absorption near-edge structure spectrum of the electrode structure of Experimental Example 1 under the charge and discharge state of the secondary battery of Experimental Example 1, Figure 56 Fig. 4 is an S L 3,2 -edge X-ray absorption near-edge structure spectrum of the electrode structure of Experimental Example 1 under the charge and discharge state of the secondary battery of Experimental Example 1, Figure 57 Fig. 5 is an S 2p X-ray photoelectron spectroscopy spectrum of the electrode structure of Experimental Example 1 under the charge and discharge state of the secondary battery of Experimental Example 1. Figure 58 Fig. 6 is a P 2p X-ray photoelectron spectroscopy spectrum of the electrode structure of Experimental Example 1 under the charge and discharge state of the secondary battery of Experimental Example 1.

[0295] Referring to Figure 54 to Figure 58 , as the charge and discharge of the secondary battery of Experimental Example 1 was performed, Cu K-edge X-ray absorption near-edge structure, S K-edge X-ray absorption near-edge structure, P L-edge X-ray absorption near-edge structure, S L-edge X-ray absorption near-edge structure, and P 2p X-ray photoelectron spectroscopy measurements were performed on the electrode structure of Experimental Example 1.

[0296] From Figure 54 it was found that reversible changes in the Cu K-edge could be confirmed in the state of being charged at 2.2 V at 1.7 V and being discharged at 0.0 V at 2.2 V.

[0297] Also, from Figure 55 part (a), in the S K-edge spectrum, as the state of being charged, the intensity of the pre-edge increased, and the broad edge increased by about 2.9 eV.

[0298] The increase in the intensity of the pre-edge means that the unoccupied state of sulfur higher than the Fermi level is enhanced, which can correspond to a redox reaction compensated by electrons of S 3p and Cu 3d. Also, the movement of the broad edge means that the electron density decreases from S 2- to S y- (y < 2).

[0299] Also, from Figure 56 and Figure 57It can be seen that after charging, two additional peaks with high binding energies of 162.2–163.3 eV can be identified in the S 2p X-ray photoelectron spectrum, SL. 3,2 - The edge shifted by 1.5 eV, which means that the partially oxidized S n- (n < 2). It can be seen that after discharge, the two additional peaks disappeared in the S 2p X-ray photoelectron spectrum, and SL... 3,2 - The edge returned to its state before charging, thus confirming that the redox reaction of sulfur can proceed reversibly.

[0300] from Figure 55 Part (b) and Figure 58 It can be seen that the reversible redox reaction of phosphorus can be confirmed during charging and discharging. After charging, the leading edge and wide edge shift by approximately 0.41 eV and 0.32 eV, respectively, and two additional peaks can be confirmed in the S 2p X-ray photoelectron spectroscopy, thereby confirming the oxidation of phosphorus (P). 2- P n- The presence of (2 < n < 3) is also evident. Furthermore, it is known that after discharge, the two additional peaks in the S 2p X-ray photoelectron spectrum disappear and return to the state before charging, confirming that a reversible redox reaction has occurred.

[0301] Figure 59 This is a high-resolution transmission electron microscope image of the electrode structure of Experimental Example 1, taken under the charge and discharge conditions of the secondary battery in Experimental Example 1 of this application.

[0302] Reference Figure 59 High-resolution transmission electron microscopy (TEM) images of the electrode structure of Experimental Example 1 were taken under charging and discharging conditions of the secondary battery in Experimental Example 1. CuP was used. 0.1 S 0.9 CuP 0.5 S 0.5 and CuP 0.9 S 0.1 The electrode structure used in Experiment Example 1. Figure 59 Parts a, b, and c are CuP 0.1 S 0.9 High-resolution transmission electron microscope image, Figure 59 The d, e, and f parts are CuP 0.5 S 0.5 High-resolution transmission electron microscope image, Figure 59 The g, h, and i parts are CuP 0.9 S 0.1 High-resolution transmission electron microscopy image.

[0303] As mentioned above, in CuP 0.1 S 0.9 and CuP0.9 S 0.1 In the case of Cu, since the redox bond of Cu is located at a higher position than the S 3p bond, it is possible to destabilize oxidized sulfur. Therefore, as shown in FIG. 6, it was confirmed that even if charging and discharging were performed, the lattice spacing could not be reversibly recovered. In contrast, in the CuPS electrode structure, as shown in FIG. 7, it was confirmed that the lattice spacing reversibly recovered after charging and discharging. Figure 59 0.5 S 0.5 In the case of CuPS, it was confirmed that the lattice spacing before charging was 0.466 nm, the lattice spacing after charging was 0.478 nm, and the lattice spacing after discharging was 0.466 nm, and that the lattice spacing reversibly recovered after charging and discharging.

[0304] Figure 60 A graph showing the characteristics of the oxygen evolution reaction, the redox reaction, and the hydrogen evolution reaction evaluated from the crystal plane in the electrode structure of Experimental Example 1 of the present application.

[0305] Referring to FIG. 8, the overpotential with respect to the oxygen evolution reaction and the redox reaction (bifunctional activity) and the overpotential with respect to the hydrogen evolution reaction were calculated from the crystal plane of the CuPS electrode structure of Experimental Example 1 using discrete Fourier transform. Figure 60 From FIG. 8, it was confirmed that the overpotential value of the (101) crystal plane was the lowest, and thus it was confirmed that the characteristics of the redox reaction, the oxygen evolution reaction, and the hydrogen evolution reaction of the electrode structure in which the (101) crystal plane was developed according to the embodiment of the present application were improved.

[0306] Figure 60 In summary, it was confirmed that the above electrode structure in which the (101) crystal plane was developed and used as the positive electrode of a metal-air battery was an effective method for improving the charging and discharging characteristics of a metal-air battery.

[0307]

[0308] Figure 61 A graph showing the characteristics of the redox reaction, the oxygen evolution reaction, and the hydrogen evolution reaction evaluated from the composition ratio of P and S of the electrode structure of Experimental Example 1 of the present application.

[0309] Referring to FIG. 9, the characteristics of the redox reaction, the oxygen evolution reaction, and the hydrogen evolution reaction were measured and shown from the composition ratio of P and S in the CuPS electrode structure of Experimental Example 1. Figure 61 From FIG. 9, it was confirmed that the characteristics of the redox reaction, the oxygen evolution reaction, and the hydrogen evolution reaction were improved as the composition ratio of P and S increased.

[0310] Figure 61 ​​​​As can be seen, in the CuPS electrode structure, it was confirmed that the redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics were excellent when the composition ratio of P was greater than 0.3 and less than 0.7 and the composition ratio of S was less than 0.7 and greater than 0.3. That is, it was confirmed that the method of 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 in the CuPS electrode structure was an effective method of improving the redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics.

[0311] Figure 62 Cu 2p, P 2p, and S 2p X-ray photoelectron spectroscopy spectra according to the composition ratios of P and S of the electrode structure of Experimental Example 1 of the present application.

[0312] Referring to Figure 62 In the CuPS electrode structure of Experimental Example 1, Cu 2p, P 2p, and S 2p X-ray photoelectron spectroscopy measurements according to the composition ratios of P and S were performed, and the calculated composition ratios are shown in Table 4 below.

[0313] Table 4

[0314] CP x S 1-x x value in the formula (I) Cu (atomic percentage) P (atomic percentage) S (atomic percentage) 0.1 49.56 10.21 40.23 0.3 49.19 19.93 30.88 0.5 48.92 24.89 26.19 0.7 49.16 30.48 20.36 0.9 48.86 40.99 10.15

[0315] Figure 63 a graph for evaluating the redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics according to the composition ratios of Cu and S of the electrode structure of Experimental Example 3 of the present application, Figure 64 a graph of X-ray diffraction according to the composition ratios of Cu and S of the electrode structure of Experimental Example 3 of the present application, Figure 65 a graph showing the lattice parameter according to the composition ratios of Cu and S of the electrode structure of Experimental Example 3 of the present application.

[0316] Referring to Figure 63 and Figure 64 In the CuS electrode structure of Experimental Example 3, the redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics were measured according to the ratios of Cu and S, X-ray diffraction measurements were performed, and the lattice parameter values were calculated.

[0317] From Figure 63 and Figure 64 As can be seen, in the case of the CuS electrode structure of Experimental Example 3, it was confirmed that the CuS electrode structure had a copper blue crystalline phase and improved redox reaction, oxygen evolution reaction, and hydrogen evolution reaction characteristics when the composition ratio of S was greater than or equal to 0.35 and less than or equal to 0.6. Also, it was confirmed that when the composition ratio of S was greater than 0.6, phases such as S and CuS2 mixed with residual CuS and Cu2S were observed, and when the composition ratio of S was less than 0.35, Cu2S and chalcocite phases appeared.

[0318] Also, fromFigure 65 As can be seen, as the composition ratio of S increases, the lattice parameter of the unit cell of the electrode structure of Experimental Example 3 increases, and the volume of the unit cell thus increases, and therefore, as shown in Figure 49 , it can be confirmed that the peak moves.

[0319] Figure 66 A graph for comparing the discharge voltage according to the current density of the zinc-air battery including the electrode structure of Experimental Example 1 of the present application.

[0320] Referring to Figure 66 , a comparative example of a zinc-air battery was prepared using a Pt / C and RuO2 positive electrode, an A201 (Tokuyama Corporation) electrolyte, and a zinc negative electrode, and the discharge voltage at 5 mAcm -2 ~ 200 mAcm -2 of current density was measured in comparison with the zinc-air battery including the electrode structure of Experimental Example 1.

[0321] As can be seen from Figure 66 , it can be confirmed that the discharge voltage of the zinc-air battery including the CuPS electrode structure of Experimental Example 1 is significantly high, and in particular, it can be confirmed that the higher the current density, the more the discharge voltage of the zinc-air battery including the comparative example Pt / C and RuO2 positive electrode decreases. In contrast, it can be confirmed that the discharge voltage of the zinc-air battery including the CuPS electrode structure of Experimental Example 1 does not greatly decrease even under the condition of a high current density, in comparison with the comparative example zinc-air battery.

[0322] Figure 67 A graph for illustrating the charge and discharge capacity of the zinc-air battery of Experimental Example 1 of the present application.

[0323] Referring to Figure 67 , the capacity according to the current density of the above-described comparative example zinc-air battery and the zinc-air battery of Experimental Example 1 was measured.

[0324] As can be seen from Figure 67 , it can be confirmed that the zinc-air battery of Experimental Example 1 including the CuPS electrode structure has a higher capacity value than the comparative example zinc-air battery using Pt / C and RuO2 as the positive electrode under the condition of 25 mAcm -2 , and under the condition of 50 mAcm -2 , regardless of whether it is under the condition of 25 mAcm -2 .

[0325] Figure 68 A graph for measuring the voltage value according to the number of charge and discharge of the zinc-air battery of Experimental Example 1 of the present application.

[0326] Referring to Figure 68 , the voltage value was measured according to the number of charge and discharge under the condition of 50 mAcm -2 and 25 mA -2Under the above conditions, the voltage value according to the number of charge and discharge times was measured for the zinc-air battery of Experimental Example 1.

[0327] From Figure 68 It was confirmed that stable driving was possible during about 600 charge and discharge times. That is, it was confirmed that the CuPS electrode structure prepared according to the above-described embodiment of the present application can be stably used as a positive electrode together with a solid electrolyte.

[0328] The present application has been described in detail using preferred embodiments, but the scope of the present application is not limited to the specific embodiments, but should be interpreted by the scope of the appended claims. Also, it should be understood that modifications and variations can be made by those skilled in the art without departing from the scope of the present application.

[0329] Industrial applicability

[0330] The electrode structure of the embodiment of the present application can be used in various industrial fields such as electrochemical devices such as secondary batteries, energy storage devices, batteries for electric vehicles, water electrolysis cells, and fuel cells.

Claims

1. An electrode structure, characterized in that, It contains a membrane formed of multiple fibers. As a result of the X-ray diffraction analysis of the above electrode structure, the peak value corresponding to the (101) crystal plane has the highest value compared to the peak values ​​corresponding to other crystal planes. The above-mentioned fiber is represented by the following chemical formula 1: Chemical Formula 1 CuP x S y Where x+y=1, 0.3≤x≤0.7, 0.3≤y≤0.

7.

2. The electrode structure according to claim 1, characterized in that, A peak corresponding to the (101) crystal plane was observed in the range of 2θ values ​​from 19° to 21°.

3. A metal-air battery, characterized in that, Include: A positive electrode comprising the electrode structure described in claim 1, wherein oxygen is used as the positive electrode active material; The negative electrode is located on top of the aforementioned positive electrode; and The electrolyte is located between the positive electrode and the negative electrode.

4. The metal-air battery according to claim 3, characterized in that, Under the discharge state of the aforementioned metal-air battery, the high-resolution transmission electron microscopy analysis of the aforementioned film, which serves as the aforementioned electrode structure, shows a lattice spacing of 0.466 nm.

5. The metal-air battery according to claim 3, characterized in that, Under the charging state of the aforementioned metal-air battery, the high-resolution transmission electron microscopy analysis of the aforementioned film, which serves as the aforementioned electrode structure, shows a lattice spacing of 0.478 nm.

6. The metal-air battery according to claim 3, characterized in that, X-ray diffraction analysis of the film, which is the electrode structure described above, showed a base peak in the range of 18.5° to 19.5°. As the aforementioned metal-air battery was charged in a discharged state, the 2θ value of the aforementioned base peak was observed to gradually decrease in the range of 19° to 21°.

7. The metal-air battery according to claim 6, characterized in that, As the aforementioned metal-air battery is charged in a discharged state, the aforementioned base peak is divided into two.

8. The metal-air battery according to claim 3, characterized in that, In the discharge state of the aforementioned metal-air battery, the phosphorus contained in the aforementioned film has an oxidation state of 2-. In the charging state of the aforementioned metal-air battery, the phosphorus contained in the aforementioned membrane has oxidation numbers of 2 and n, wherein 2 < n < 3.

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