Anode for aqueous zinc metal battery and its manufacturing method

Abstract

The present invention relates to a method for manufacturing a negative electrode for an aqueous zinc battery, comprising the steps of: preparing a zinc substrate; and forming a metal oxide layer on the prepared zinc substrate through a magnetron sputtering method, and to a negative electrode for an aqueous zinc battery manufactured thereby.

Description

Technology Field

[0001] The present invention relates to a negative electrode for an aqueous zinc battery and a method for manufacturing the same, wherein Zn dendrite growth is suppressed for a negative electrode for an aqueous zinc battery and a method for manufacturing the same. Background Technology

[0002] Rechargeable aqueous zinc metal batteries (ZMBs) have the unique advantages of a metallic Zn cathode, such as high safety, low cost, excellent theoretical capacity (5855 mAh / L, 850 mAh / g), and a low electrochemical potential (-0.76 V compared to a standard hydrogen electrode).

[0003] However, the commercial use of aqueous ZMB is significantly limited due to several critical issues associated with zinc anodes. Unstable Zn electrode / electrolyte interfaces induce side reactions such as hydrogen evolution (HER) and Zn corrosion, leading to reduced Coulomb efficiency and battery capacity.

[0004] Meanwhile, uncontrolled Zn dendrite growth caused by the non-uniform interfacial electric field and ion concentration distribution of the Zn electrode affects battery life and can even lead to failure. In addition, dendrite formation increases the contact area between the electrode and the electrolyte, accelerating electrolyte consumption and electrode corrosion. As a result, when the local alkaline environment improves, byproducts (such as Zn4SO4(OH)6-xH2O) accumulate on the electrode surface, affecting Zn deposition behavior and exacerbating the electrochemical instability of the zinc anode.

[0005] To solve this problem, conventional efforts have focused on forming an artificial interface layer between the electrode and the electrolyte interface. The artificial interface layer can control the Zn deposition behavior by redistributing the interfacial electric field and Zn ion flux, and can also suppress HER by avoiding a direct connection between the Zn electrode and the electrolyte.

[0006] Many recent studies have focused on interfacial stress caused by semi-coherent or incoherent interfaces during Zn deposition, which hinders the long-term stable operation of Zn cathodes, and have proposed strategies for lattice matching and interfacial stress emission. However, the influence of lattice stress resulting from Zn ion diffusion through the interfacial layer lattice on the behavior of Zn metal deposition has rarely been discussed. The problem to be solved

[0007] The present invention was devised to solve the aforementioned conventional problems and aims to provide a negative electrode for an aqueous zinc battery and a method for manufacturing the same, wherein a metal oxide layer is formed on the Zn negative electrode to suppress the formation of Zn dendrites. means of solving the problem

[0008] The present invention discloses a method for manufacturing a negative electrode for an aqueous zinc battery, comprising the steps of: preparing a zinc substrate; and forming a metal oxide layer on the prepared zinc substrate through a magnetron sputtering method, as a means to achieve the above-described objective.

[0009] Here, the metal oxide layer is ITO, AZO, GZO, FTO, IZGO, CuO2, CuO, FeO, Fe3O4, Fe4O5, Fe5O6, Fe5O7, Fe2O3, ZnO, Ag2O, AgO, rutile-TiO2, anatase-TiO2, SnO, FTO, In2O3, NiO, Ni2O3, CuAlO2, CuGaO2, SrCu2O2, LaCuOS, LaCuOSe, CuInO2, ZnRh2O4, 12CaO·7Al2O3(C 12 It may include one or more materials selected from the group consisting of A7) and Ga2O3.

[0010] Here, defects may be induced as the metal oxide layer is formed on the zinc substrate.

[0011] Here, the lattice oxygen (Oxygen Lattice, O) included in the metal oxide layer L ) is vacancy oxygen (Oxygen vacancy, O) at the interface with the zinc substrate. V It can change into ).

[0012] Here, the magnetron stuffing method can be performed for 5 to 25 minutes.

[0013] Here, the deposition pressure of the magnetron sputtering method may be 1 to 10 mTorr.

[0014] Here, the sputtering power of the magnetron sputtering method may be 10 to 50 W.

[0015] In addition, the present invention discloses a negative electrode for an aqueous zinc battery, which is manufactured through the method described above as a means to achieve the above-described purpose and comprises: a zinc substrate; and a metal oxide layer formed on the zinc substrate.

[0016] Here, the thickness of the metal oxide layer may be 10 to 50 nm.

[0017] Here, the thickness of the zinc substrate may be 0.1 to 20 mm.

[0018] Here, the surface of the above cathode may be hydrophobic. Effects of the invention

[0019] The negative electrode for an aqueous zinc battery according to the present invention can accelerate Zn ion diffusion at the interface, improve the corrosion resistance of the electrode, and suppress dendrite formation by forming a metal oxide layer as an artificial interface layer on the surface of a zinc substrate (electrode).

[0020] The method for manufacturing a negative electrode for an aqueous zinc battery according to the present invention utilizes a magnetron sputtering method, thereby enabling the production of a negative electrode for an aqueous zinc battery with improved corrosion resistance and suppressed dendrite formation through a more simplified process. Brief explanation of the drawing

[0021] Figure 1 is a flowchart illustrating the manufacturing process of a negative electrode for an aqueous zinc battery according to the present invention. FIG. 2 is a schematic diagram illustrating an apparatus used in the magnetron sputtering method of the present invention. Figure 3 is a schematic diagram illustrating the change in lattice oxygen and void oxygen during the manufacturing process of the present invention. Figure 4 is an SEM image of the surface of a cathode manufactured according to one embodiment of the present invention. Figure 5 is an SEM image of a cross-section of a cathode manufactured according to one embodiment of the present invention. Figure 6 shows the surface contact angle of a cathode manufactured according to one embodiment of the present invention. FIG. 7 is a schematic diagram showing a cross-section of a cathode after Zn deposition manufactured according to one embodiment of the present invention. Figure 8 is an SEM image of the surface of a cathode after Zn deposition manufactured according to one embodiment of the present invention. Figure 9 is an HRTEM image of a cathode before and after Zn deposition prepared according to one embodiment of the present invention. FIG. 10 illustrates the zinc ion and water molecule binding energy of a cathode manufactured according to one embodiment of the present invention. FIG. 11 is an SEM image of a cross-section of a cathode after Zn deposition manufactured according to one embodiment of the present invention. FIG. 12 is the result of a cycling evaluation of a symmetric cell including a cathode manufactured according to one embodiment of the present invention. FIG. 13 is the result of a cycling evaluation of a symmetric cell including a cathode manufactured according to one embodiment of the present invention. Specific details for implementing the invention

[0022] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0023] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0024] As used herein, terms of degree such as “about,” “substantially,” etc., are used to mean at or near the stated value when inherent manufacturing material tolerances are presented in the said sense, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosed content in which precise or absolute values ​​are mentioned to aid in understanding the invention. Furthermore, throughout this specification, “a step of” or “a step of” does not mean “a step for”.

[0025] Since a person skilled in the art can make various applications through the gist of the present invention, the scope of the rights of the present invention is not limited to the following embodiments. The scope of the rights of the present invention extends to parts that are obvious to a person skilled in the art who can easily substitute or modify using prior art based on the matters described in the specific claims.

[0026] The present invention will be described in more detail below with reference to the attached drawings, where necessary.

[0028] Method for manufacturing a negative electrode for a water-based zinc battery

[0029] The present invention discloses a method for manufacturing a negative electrode for an aqueous zinc battery as a means to achieve the above-mentioned objective.

[0030] FIG. 1 is a flowchart illustrating the manufacturing process of a negative electrode for an aqueous zinc battery according to the present invention. Referring to FIG. 1, it can be seen that the manufacturing method of the present invention includes the step of preparing a zinc substrate; and the step of forming a metal oxide layer on the prepared zinc substrate through a magnetron sputtering method.

[0031] Below, the manufacturing method of the present invention will be explained in more detail by subdividing it into each step.

[0032] First, the manufacturing method of the present invention includes the step of preparing a zinc substrate.

[0033] Next, the manufacturing method of the present invention includes the step of forming a metal oxide layer on the prepared zinc substrate through a magnetron sputtering method.

[0034] FIG. 2 is a schematic diagram illustrating an apparatus used in the magnetron sputtering method of the present invention. Referring to FIG. 2, it can be seen that the apparatus includes a magnet, an anode, a target, and a holder. The principle of the magnetron sputtering method is explained as follows. First, the magnet of the magnetron is rotated to generate a high frequency. Electrons are accelerated by the high frequency, and their trajectories are bent by a strong magnetic field, thereby generating electromagnetic waves through bremsstrahlung radiation. Gas in a plasma state is collided with the target to eject atoms from the target. The ejected atoms can be attached to a substrate to form a thin film. In the manufacturing method of the present invention, by utilizing the magnetron sputtering method, the effect of easily forming a large-area metal oxide thin film can be expected.

[0035] In other words, the present invention aims to suppress the formation of Zn dendrites and control Zn deposition behavior by forming an artificial interface layer containing a metal oxide at the Zn cathode / electrolyte interface using the magnetron sputtering method described above. The artificial interface layer can not only control Zn deposition behavior by redistributing the interfacial electric field and Zn ion flux, but also suppress HER by avoiding direct contact between the Zn electrode and the electrolyte, thereby allowing for the expectation of stabilization of the Zn cathode. The metal oxide-derived Zn cathode interface layer can more effectively control the Zn electrode / electrolyte interface chemistry due to its high hydrogen evolution overpotential and excellent electrochemical inertness. In particular, metal oxide defect engineering can further accelerate Zn ion transport kinetics, prevent electrode corrosion during cell operation, and achieve uniform Zn deposition.

[0036] Here, it is preferable that the magnetron sputtering method be performed for 5 to 25 minutes. If the magnetron sputtering method is performed for less than 5 minutes, the surface of the metal oxide layer formed on the zinc substrate may be formed unevenly. Such an uneven surface may cause a problem where the zinc is deposited in a rough state on the electrode surface during subsequent zinc deposition. This problem may result in the deposited zinc not being formed densely, leading to a decrease in electrode capacity and stability. On the other hand, if the magnetron sputtering method is performed for more than 25 minutes, not only does the thickness of the deposited metal oxide layer increase, but a problem may also occur where cracks form on the surface of the metal oxide layer. These surface cracks can cause the electric field to concentrate, leading to Zn ions preferentially accumulating in the corresponding area during zinc deposition, which can disrupt the interfacial ion distribution. This problem may also result in a decrease in electrode capacity and stability.

[0037] Here, the deposition pressure of the magnetron sputtering method is preferably 1 to 10 mTorr.

[0038] Here, the sputtering power of the magnetron sputtering method is preferably 10 to 50 W.

[0039] If the deposition pressure and power of the above method fall outside the range described above, it may become difficult to form a metal oxide layer of sufficient thickness to prevent direct contact between the Zn cathode and the electrolyte, or a problem may arise in which the surface of the metal oxide layer is formed unevenly.

[0040] FIG. 3 is a schematic diagram illustrating changes in lattice oxygen and void oxygen during the manufacturing process of the present invention. More specifically, it illustrates the elemental distribution immediately after the manufacture of the cathode, lattice deformation in the metal oxide (ITO) layer caused by the ion migration of Zn, and the electrostatic adsorption process in the metal oxide layer where lattice deformation is induced.

[0041] Referring to Fig. 3, it can be observed that as a metal oxide, ITO, is deposited on the surface of the Zn cathode, ITO lattice deformation is induced due to Zn ion migration. More specifically, the lattice oxygen (O) of ITO L ) is void oxygen (O V It changes to ), and accordingly, O on the Zn electrode surface V It can be confirmed that an interface layer rich in [something] is formed. In this way, O V When a layer rich in [a specific component] is formed, the energy barrier for Zn ion diffusion in the electrolyte is lowered due to electrostatic adsorption, and appropriate anions are captured to improve Zn ion mobility and electrode corrosion prevention, and furthermore, a highly reversible dendrite-free Zn cathode can be produced.

[0042] Here, the metal oxide layer is ITO, AZO, GZO, FTO, IZGO, CuO2, CuO, FeO, Fe3O4, Fe4O5, Fe5O6, Fe5O7, Fe2O3, ZnO, Ag2O, AgO, rutile-TiO2, anatase-TiO2, SnO, FTO, In2O3, NiO, Ni2O3, CuAlO2, CuGaO2, SrCu2O2, LaCuOS, LaCuOSe, CuInO2, ZnRh2O4, 12CaO·7Al2O3(C 12 It may include one or more materials selected from the group consisting of A7) and Ga2O3, but is not limited thereto. In the present invention, the most preferred example of the metal oxide may be ITO.

[0043] Here, defects may be induced as the metal oxide layer is formed on the zinc substrate. Lattice oxygen (Oxygen Lattice, O) included in the metal oxide layer L ) is vacancy oxygen (Oxygen vacancy, O) at the interface with the zinc substrate. V It can change into ).

[0044] The aforementioned defect refers to a defect induced in the metal oxide lattice, and a larger amount of lattice defects may be induced as Zn deposition is performed after the formation of the metal oxide layer. The strain of the metal oxide (degree of defect occurrence) after Zn deposition may be attributed to the migration of Zn ions inducing additional stress in the metal oxide lattice, and localized stress concentrations disrupting the original aligned atomic arrangement. Accordingly, the lattice oxygen (O) of the metal oxide L ) is void oxygen (O V It can change into ).

[0046] <Cathode for Water-based Zinc Batteries>

[0047] In addition, the present invention discloses a negative electrode for an aqueous zinc battery manufactured through the method described above as a means to achieve the above-described purpose.

[0048] The negative electrode for an aqueous zinc battery of the present invention may include a zinc substrate; and a metal oxide layer formed on the zinc substrate.

[0049] Here, the metal oxide layer functions as an artificial interface layer placed between the zinc substrate (electrode) and the electrolyte, and this metal oxide layer can control the Zn deposition behavior during the operation of an aqueous zinc battery by redistributing the interfacial electric field and Zn ion flux. In addition, by avoiding a direct connection between the Zn electrode and the electrolyte, HER can be suppressed, thereby promoting the stabilization of the Zn anode.

[0050] Here, the thickness of the metal oxide layer is preferably 10 to 50 nm. If the thickness of the metal oxide layer is less than 10 nm, the control of the interfacial electric field is insufficient, and the intended dendrite inhibition and corrosion prevention effects may be negligible. On the other hand, if the thickness of the metal oxide layer exceeds 50 nm, void oxygen (O₂) caused by metal oxide lattice deformation V A problem may occur where ) is not sufficiently formed. A sufficient amount of O V If it is not formed, it is difficult to expect the reduction of the Zn ion diffusion energy barrier in the electrolyte due to electrostatic adsorption, as well as the effects of Zn ion migration dynamics and electrode corrosion prevention.

[0051] Here, the thickness of the zinc substrate is preferably 0.1 to 20 mm.

[0052] Here, the surface of the cathode may exhibit hydrophobicity. As the surface of the cathode of the present invention exhibits hydrophobicity, the effect of delaying the corrosion of the electrode due to contact with the electrolyte can be expected.

[0053] In addition, when using the cathode of the present invention, zinc can be deposited in the space between the zinc substrate (electrode) and the metal oxide layer during battery operation. As the metal oxide layer is formed on the zinc substrate, Zn ion diffusion is accelerated, and Zn deposition behavior can be controlled.

[0054] In addition, when the cathode of the present invention is used, the hydrogen generation reaction is suppressed, and ZnSO4OH - The formation of by-products such as the above can be suppressed. The suppression of the formation of the above by-products may mean that the corrosion resistance of the cathode of the present invention is excellent.

[0055] Hereinafter, the claims of this specification will be explained in more detail with reference to the attached drawings and embodiments. However, as the drawings and embodiments presented in this specification may be modified in various ways by a person skilled in the art and may take various forms, the details described in this invention should not be limited to a specific disclosed form, but should be understood to include all equivalents and substitutions included within the spirit and scope of the invention. Furthermore, the attached drawings are presented to help a person skilled in the art understand the invention more accurately and may be depicted in an exaggerated or reduced size compared to the actual size.

[0057] {Examples and Evaluation}

[0058] <Example>

[0059] Example 1

[0060] An ITO layer was deposited on a Zn foil for 5 minutes using an RF magnetron sputtering method to produce a negative electrode for an aqueous zinc battery (hereinafter referred to as "Example 1").

[0061] Vacuum chamber pressure: 3.0 x 10⁻² mTorr

[0062] Gas type: High-purity Ar

[0063] Gas flow rate: 30 sccm

[0064] Deposition pressure: 6.5 mTorr

[0065] Sputtering Power: 25 W

[0067] Example 2

[0068] A negative electrode for an aqueous zinc battery was prepared in the same manner as in Example 1, except that the sputtering time was set to 10 minutes (hereinafter referred to as "Example 2").

[0070] Example 3

[0071] A negative electrode for an aqueous zinc battery was prepared in the same manner as in Example 1, except that the sputtering time was set to 20 minutes (hereinafter referred to as "Example 3").

[0073] Comparative Example 1

[0074] A bare zinc foil was used as the negative electrode for a swimming zinc battery without depositing an ITO layer (hereinafter referred to as "Comparative Example 1").

[0076] Comparative Example 2

[0077] A negative electrode for an aqueous zinc battery was prepared in the same manner as in Example 1, except that the sputtering time was 30 minutes (hereinafter referred to as "Comparative Example 2").

[0079] <Evaluation>

[0080] FIG. 4 is an SEM image of the surface of a cathode manufactured according to one embodiment of the present invention. More specifically, FIG. 4a and e are images of the surface of a cathode manufactured according to Example 1, FIG. 4b and f are images of the surface of a cathode manufactured according to Example 2, FIG. 4c and g are images of the surface of a cathode manufactured according to Example 3, and FIG. 4d and h are images of the surface of a cathode manufactured according to Comparative Example 2.

[0081] Referring to Fig. 4, it can be seen that the ITO coating surface tends to become smoother as the sputtering time increases, but in the case of Comparative Example 2, where the sputtering time is 30 minutes, cracks appear on the surface.

[0082] FIG. 5 is an SEM image of a cross-section of a cathode manufactured according to one embodiment of the present invention. More specifically, FIG. 5a and e are cross-sections of a cathode manufactured according to Example 1, FIG. 5b and f are cross-sections of a cathode manufactured according to Example 2, FIG. 5c and g are cross-sections of a cathode manufactured according to Example 3, and FIG. 5d and h are cross-sections of a cathode manufactured according to Comparative Example 2.

[0083] Referring to FIG. 5, in the case of Example 1, where the sputtering time is 5 minutes, it can be seen that the thickness of the ITO layer is 18 nm; in the case of Example 2, where the sputtering time is 10 minutes, it can be seen that the thickness of the ITO layer is approximately 27 nm; in the case of Example 3, where the sputtering time is 20 minutes, it can be seen that the thickness of the ITO layer is approximately 50 nm; and in the case of Comparative Example 2, where the sputtering time is 30 minutes, it can be seen that the thickness of the ITO layer is approximately 70 nm.

[0084] FIG. 6 evaluates the surface contact angle of a cathode manufactured according to one embodiment of the present invention. More specifically, FIG. 6a shows the contact angle of a cathode manufactured according to Comparative Example 1, FIG. 6b shows the contact angle of a cathode manufactured according to Example 1, FIG. 6c shows the contact angle of a cathode manufactured according to Example 2, FIG. 6d shows the contact angle of a cathode manufactured according to Example 3, and FIG. 6e shows the contact angle of a cathode manufactured according to Comparative Example 2.

[0085] Referring to Figure 6, it can be seen that as the sputtering time increases, the contact angle between the electrode and the electrolyte gradually decreases, but still exhibits hydrophobicity. This result suggests that the interface can delay the corrosion of the electrode.

[0086] FIG. 7 is a schematic diagram illustrating a cross-section of a cathode after Zn deposition prepared according to an embodiment of the present invention. More specifically, FIG. 7a illustrates a cross-section of a cathode prepared according to Example 1 after Zn deposition, FIG. 7b illustrates a cross-section of a cathode prepared according to Example 2 after Zn deposition, FIG. 7c illustrates a cross-section of a cathode prepared according to Example 3 after Zn deposition, and FIG. 7d illustrates a cross-section of a cathode prepared according to Comparative Example 2 after Zn deposition.

[0087] Referring to Fig. 7, it can be seen that the pattern of Zn deposition varies depending on the sputtering time. In the case of Example 1, a rough deposition pattern can be observed on the electrode surface after Zn deposition due to the heterogeneous interface layer. As the deposition capacity increases, a nondense structure may appear on the electrode surface. In contrast, in the case of Example 2, there are fewer disordered Zn flakes, and the precipitates may be denser and more uniform than in Example 1. This result suggests that the ITO interface has the potential to control Zn nucleation. Meanwhile, in the case of Example 3, a smooth and uniform deposition pattern can be observed regardless of the high or low Zn deposition capacity. Additionally, due to the formation of a metal oxide layer, the deposited Zn can be deposited beneath the metal oxide interface layer. The flat cross-sectional structure and uniformly deposited electrode thickness of Example 3 can induce dendrite-free and uniform Zn deposition. In contrast, in the case of Comparative Example 2, as can be seen in Figure 4 above, cracks occur on the surface. Since the electric field is concentrated at these cracked areas, Zn ions preferentially accumulate at those areas during the Zn deposition process, which disrupts the interfacial Zn ion distribution and can result in a rough surface shape. These differences can be more clearly observed in Figure 8 below.

[0088] FIG. 8 is an SEM image of the surface of a cathode after Zn deposition prepared according to one embodiment of the present invention. More specifically, FIG. 8a to 8d shows the surface of a cathode prepared according to Example 1 after Zn deposition, FIG. 8e to 8h show the surface of a cathode prepared according to Example 2 after Zn deposition, and FIG. 8i to 8l show the surface of a cathode prepared according to Comparative Example 2 after Zn deposition.

[0089] Referring to FIG. 8, as described above, in the case of Example 1, due to the heterogeneous interface layer, Zn deposition (1.0 mAh / cm²) 2A rough deposition pattern can be observed on the electrode surface after ) The deposition capacity is 3.0 mAh / cm². 2 As the value increases, it can be observed that a nondense structure is exhibited on the electrode surface. Additionally, in the case of Example 2, it can be observed that there are fewer disordered Zn flakes on the electrode surface and the precipitates are denser and more uniform than in Example 1. This result suggests that the ITO interface has the potential to control Zn nucleation. Meanwhile, in the case of Comparative Example 2, cracks occur on the electrode surface during the formation of the metal oxide layer. Since the electric field is concentrated at these crack sites, Zn ions preferentially accumulate at those sites during the Zn deposition process, causing the interfacial Zn ion distribution to be disrupted and a rough surface shape to be created.

[0090] FIG. 9 is an HRTEM image of a cathode before and after Zn deposition prepared according to one embodiment of the present invention. More specifically, FIG. 9a to c is an HRTEM image of a cathode prepared according to Example 3 before Zn deposition, and FIG. 9d to f is an HRTEM image of a cathode prepared according to Example 3 before Zn deposition.

[0091] Referring to Fig. 9a, some lattice defects indicated by black circles at the cathode prior to Zn deposition can be observed. These may be attributed to inherent defects in the metal oxide. Additionally, a lattice spacing of 0.292 nm, corresponding to the (222) crystal plane of In2O3, can be identified. Furthermore, Fig. 9b is an enlarged image of the red area in Fig. 9a, revealing a uniform crystal orientation and an aligned arrangement of different atoms in the inset image. Meanwhile, referring to Fig. 9d, more defects indicated by red circles can be observed after Zn deposition. Additionally, Fig. 9e is an enlarged view of the red area in Fig. 9d, showing lattice distortion and an increase in the lattice spacing to 0.298 nm. This is attributed to lattice deformation caused by Zn ion transport through the interface. Moreover, referring to Figs. 9c and 9f, the local strain distribution can be observed; the ITO strain distribution prior to Zn deposition is ε yy It is relatively flat along the direction, reflecting a state without initial stress consistent with a uniform crystal orientation. In contrast, the ITO strain fluctuates significantly after Zn deposition, as the migration of Zn ions induces additional stress in the ITO lattice, and local stress concentrations break the original aligned atomic arrangement, O L Part of O V It supports the transformation into.

[0092] FIG. 10 illustrates the adsorption energies of zinc ions and water molecules of a cathode manufactured according to one embodiment of the present invention. More specifically, FIG. 10a illustrates the adsorption energy with zinc ions on a zinc substrate, FIG. 10b illustrates the adsorption energy with zinc ions on the cathode of the present invention, FIG. 10c illustrates the adsorption energy with water molecules on a zinc substrate, and FIG. 10d illustrates the adsorption energy with water molecules on the cathode of the present invention.

[0093] Referring to Fig. 10, the adsorption energy of Zn atoms on a zinc substrate is -0.670 eV, and O V The adsorption energy of Zn atoms on a Zn-rich ITO substrate (the cathode of the present invention) is -0.875 eV, confirming that the cathode of the present invention is more affinity for Zn. In addition, the adsorption energy of H2O on a zinc substrate is -0.679 eV, and O V It can be confirmed that the H2O adsorption energy on a Glycerin-rich ITO substrate is -0.448 eV. This indicates O V This means that the ITO rich in [unclear] exhibits repulsion with water molecules, and ultimately O V It can be inferred that an ITO interface rich in [material] can improve the corrosion resistance of the electrode.

[0094] FIG. 11 is an SEM image of a cross-section of a cathode prepared according to an embodiment of the present invention after Zn deposition. More specifically, FIG. 11a, d, and g are cross-sections of a cathode prepared according to Example 3, and FIG. 11b, e, and h are 1.0 mAh / cm² using the cathode prepared according to Example 3. 2 This is a photograph taken after performing zinc deposition with a capacity of , and Figures 11c, f, and i show 3.0 mAh / cm² using the cathode prepared according to Example 3. 2 This is a picture taken after performing zinc deposition with the capacity of .

[0095] Referring to FIG. 11, an ITO coating can be observed in the cross-section of the cathode prepared according to Example 3, and it can be confirmed that the zinc deposited on the cathode after zinc deposition is deposited below the ITO interface layer. In other words, it can be predicted that dendrite-free Zn deposition can be induced by performing ITO coating.

[0096] FIG. 12 is the result of a cycling evaluation of a symmetric cell including a cathode manufactured according to one embodiment of the present invention. More specifically, a symmetric cell was manufactured using a cathode manufactured according to Example 3 and Comparative Example 1, and a cycling evaluation was performed thereon.

[0097] Referring to FIG. 12, a symmetric cell including a cathode prepared according to Example 3 has a power of 5.0 mA / cm² 2 , 1.0 mAh / cm 2 It can be seen that stable cycling is maintained for 2000 hours, whereas the symmetric cell containing the cathode prepared according to Comparative Example 1 exhibits a short circuit at 595 hours due to large voltage hysteresis.

[0098] FIG. 13 is a cycling evaluation result of a symmetric cell including a cathode manufactured according to an embodiment of the present invention. More specifically, FIG. 13a is a graph showing the cycling evaluation result of a symmetric cell including a cathode manufactured according to Examples 1 to 3 and Comparative Examples 1 to 2, FIG. 13b is a graph showing the cycling evaluation result of a symmetric cell including a cathode manufactured according to Example 3 and Comparative Example 1, and FIG. 13c is a graph showing the cycling evaluation result according to current density of a symmetric cell including a cathode manufactured according to Example 3 and Comparative Example 1.

[0099] Referring to FIG. 13, a symmetric cell including a cathode prepared according to Example 3 has a power of 1.0 mA / cm² 2 and 1.0 mAh / cm² 2 It can be confirmed that it provides very stable cycling performance with smooth voltage polarization for over 4,500 hours (2,250 cycles). On the other hand, it can be confirmed that the symmetrical cells containing the cathodes prepared according to Comparative Example 2, Example 2, Example 1, and Comparative Example 1 operate only for 3,230, 2,240, 1,370, and 660 hours, respectively. Furthermore, the symmetrical cell containing the cathode prepared according to Example 3 operates at 5.0 mA / cm² 2and 2.0 mAh / cm² 2 It can be confirmed that it provides a significantly long cycle life of 3,000 hours, offering remarkably superior performance compared to the cathode prepared according to Comparative Example 1 (150 hours). This phenomenon strongly supports the fact that the reversibility and stability of the Zn cathode with a free-formed interface have been greatly improved. Furthermore, referring to Fig. 13c, 0.5 to 5.0 mA / cm² 2 It can be seen that, at various current densities, the cathode prepared according to Comparative Example 1 short-circuits at 210 hours, whereas the electrode prepared according to Example 3 exhibits lower voltage hysteresis and stronger cycling reversibility. Additionally, the cathode prepared according to Example 3 exhibits a higher exchange current density than Comparative Example 1, suggesting that the Zn deposition motion is faster.

[0100] The negative electrode for an aqueous zinc battery according to the present invention can accelerate Zn ion diffusion at the interface, improve the corrosion resistance of the electrode, and suppress dendrite formation by forming a metal oxide layer as an artificial interface layer on the surface of a zinc substrate (electrode).

[0101] The method for manufacturing a negative electrode for an aqueous zinc battery according to the present invention utilizes a magnetron sputtering method, thereby enabling the production of a negative electrode for an aqueous zinc battery with improved corrosion resistance and suppressed dendrite formation through a more simplified process.

[0103] The above description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention.

[0104] Accordingly, the embodiments disclosed in this invention are intended to illustrate, not limit, the technical concept of the invention, and the scope of the technical concept of the invention is not limited by these embodiments. The scope of protection of this invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of this invention.

Claims

Claim 1 The method comprises the steps of: preparing a zinc substrate; and forming a metal oxide layer on the prepared zinc substrate through a magnetron sputtering method, wherein the lattice oxygen (Oxygen Lattice, O) included in the metal oxide layer L ) is vacancy oxygen (Oxygen vacancy, O) at the interface with the zinc substrate. V Method for manufacturing a negative electrode for an aqueous zinc battery, changing into ). Claim 2 In claim 1, the metal oxide layer is ITO, AZO, GZO, FTO, IZGO, CuO2, CuO, FeO, Fe3O4, Fe4O5, Fe5O6, Fe5O7, Fe2O3, ZnO, Ag2O, AgO, rutile-TiO2, anatase-TiO2, SnO, FTO, In2O3, NiO, Ni2O3, CuAlO2, CuGaO2, SrCu2O2, LaCuOS, LaCuOSe, CuInO2, ZnRh2O4, 12CaO·7Al2O3(C 12 A method for manufacturing a negative electrode for an aqueous zinc battery comprising one or more materials selected from the group consisting of A7) and Ga2O3. Claim 3 A method for manufacturing a negative electrode for an aqueous zinc battery, wherein, in claim 1, the metal oxide layer is formed on the zinc substrate to induce defects. Claim 4 A method for manufacturing a negative electrode for an aqueous zinc battery, wherein the magnetron sputtering method is performed for 5 to 25 minutes in claim 1. Claim 5 A method for manufacturing a negative electrode for an aqueous zinc battery according to claim 1, wherein the deposition pressure of the magnetron sputtering method is 1 to 10 mTorr. Claim 6 A method for manufacturing a negative electrode for an aqueous zinc battery according to claim 1, wherein the sputtering power of the magnetron sputtering method is 10 to 50 W. Claim 7 A zinc substrate manufactured by a method according to any one of claims 1 to 6; and a metal oxide layer formed on the zinc substrate; wherein the lattice oxygen (Oxygen Lattice, O) included in the metal oxide layer L ) is vacancy oxygen (Oxygen vacancy, O) at the interface with the zinc substrate. V A cathode for water-based zinc batteries that changes into ). Claim 8 A negative electrode for an aqueous zinc battery according to claim 7, wherein the thickness of the metal oxide layer is 10 to 50 nm. Claim 9 A negative electrode for an aqueous zinc battery according to claim 7, wherein the thickness of the zinc substrate is 0.1 to 20 mm. Claim 10 A cathode for an aqueous zinc battery, wherein the surface of the cathode is hydrophobic in claim 7. Claim 11 delete

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