Method for manufacturing zinc anode, zinc anode manufactured using same, and zinc ion battery including same

Abstract

Disclosed are a method for manufacturing a zinc anode, a zinc anode manufactured by using the method, and a zinc ion battery comprising the zinc anode. The present invention is characterized by comprising: a step for producing a hexagonal boron nitride solution by mixing hexagonal boron nitride, a binder polymer, and a solvent; and a step for manufacturing a zinc anode by spraying the hexagonal boron nitride solution on a zinc foil, wherein the zinc anode includes the hexagonal boron nitride sprayed on the zinc foil.

Description

Method for manufacturing a zinc anode, a zinc anode manufactured using the same, and a zinc ion battery comprising the same

[0001] The present invention relates to a method for manufacturing a zinc anode, a zinc anode manufactured using the same, and a zinc ion battery including the same. More specifically, the present invention relates to a method for manufacturing a zinc anode having excellent stability through hexagonal boron nitride scattering, a zinc anode manufactured using the same, and a zinc ion battery including the same.

[0002]

[0003] A global consensus is forming on the severity of climate change caused by global warming. In response, the Korean government is also proposing energy-related policies, such as the 2050 Carbon Neutrality Plan and the 2030 Renewable Energy Implementation Plan, and the related market is rapidly growing. In particular, the importance of clean energy supply is growing to replace fossil fuels, considered the primary culprit of global warming.

[0004] Representative clean energy sources include renewable energy sources like solar and wind power. Renewable energy generation presents challenges in ensuring a continuous energy supply, making the construction of large-capacity energy storage systems essential to addressing this issue.

[0005] To store power-scale energy, the development of eco-friendly, high-capacity, high-stability, low-cost, and low-risk batteries is essential. Therefore, aqueous zinc-ion batteries are attracting attention as next-generation, high-capacity energy storage devices. Zinc is inexpensive, has a low risk of depletion, and boasts high theoretical capacity. Furthermore, because they can operate in aqueous environments, they significantly reduce environmental hazards and the risk of explosion.

[0006] The zinc foil used as the cathode easily reacts with the electrolyte to form an unstable interface, and during battery operation, zinc is deposited in a dendritic form on the surface of the zinc foil, which reduces active zinc and increases the risk of a short circuit.

[0007] Therefore, there is a problem that the zinc foil used as the cathode easily reacts with the electrolyte to form an unstable interface, and the separator is pierced by dendritic growth, causing a short circuit.

[0008]

[0009] An embodiment of the present invention provides a method for manufacturing a zinc anode capable of suppressing zinc dendrites and ensuring high stability by spraying hexagonal boron nitride (h-BN) onto a zinc foil at regular intervals through a spraying process to manufacture a zinc anode, and assembling the zinc anode into an aqueous zinc ion battery, and a zinc anode manufactured using the same, and a zinc ion battery including the same.

[0010] An embodiment of the present invention designs a zinc anode structure in which bulk-shaped hexagonal boron nitride is obliquely erected at regular intervals on a zinc foil to suppress zinc dendrites, thereby improving the stability of a battery by suppressing zinc dendrites. An embodiment of the present invention provides a method for manufacturing a zinc anode, a zinc anode manufactured using the same, and a zinc ion battery including the same.

[0011]

[0012] A method for manufacturing a zinc anode according to an embodiment of the present invention includes the steps of: preparing a hexagonal boron nitride solution by mixing hexagonal boron nitride, a binder polymer, and a solvent; and spraying the hexagonal boron nitride solution onto a zinc foil to manufacture a zinc anode; wherein the zinc anode includes the hexagonal boron nitride scattered on the zinc foil.

[0013] The above zinc anode can be grown three-dimensionally by the above hexagonal boron nitride.

[0014] The bonding angle of the above hexagonal boron nitride to the surface of the zinc foil may be 20° to 30°.

[0015] The above hexagonal boron nitride may be present in an amount of 10 wt% to 20 wt% based on 100 wt% of the above hexagonal boron nitride solution.

[0016] The binder polymer may be present in an amount of 1 wt% to 2 wt% based on 100 wt% of the hexagonal boron nitride solution.

[0017] The above binder polymer may include at least one of polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (poly(1,1,2,2-tetrafluoroethylene); PTFE).

[0018] The solvent may include at least one of N-methyl-2-pyrrolidone (hereinafter referred to as NMP), ethanol, and isopropyl alcohol.

[0019] The application time of the above ultrasound may be 30 to 60 minutes.

[0020] The injection time of the above hexagonal boron nitride solution may be 4 to 12 seconds.

[0021] A zinc anode according to an embodiment of the present invention is manufactured according to a method for manufacturing a zinc anode according to an embodiment of the present invention, and includes: a zinc foil; and hexagonal boron nitride scattered on the zinc foil.

[0022] The above zinc anode can be grown three-dimensionally by the above hexagonal boron nitride.

[0023] The bonding angle of the above hexagonal boron nitride to the surface of the zinc foil may be 20° to 30°.

[0024] A zinc ion battery according to an embodiment of the present invention comprises: a zinc anode according to an embodiment of the present invention; a cathode positioned opposite the zinc anode; a separator disposed between the zinc anode and the cathode; and an electrolyte filled between the zinc anode and the cathode; wherein the zinc anode comprises hexagonal boron nitride dispersed on a zinc foil.

[0025]

[0026] According to an embodiment of the present invention, in order to suppress zinc dendrites, a zinc anode is manufactured by spraying hexagonal boron nitride (h-BN) onto a zinc foil through a spraying process, thereby scattering hexagonal boron nitride at regular intervals on the zinc foil, and the zinc anode is assembled into an aqueous zinc ion battery, thereby providing a method for manufacturing a zinc anode capable of suppressing dendrites and ensuring high stability due to the same, a zinc anode manufactured using the same, and a zinc ion battery including the same.

[0027] According to an embodiment of the present invention, in order to suppress zinc dendrites, a zinc anode structure is designed in which bulk-shaped hexagonal boron nitride is obliquely erected at regular intervals on a zinc foil, thereby suppressing zinc dendrites and improving the stability of a battery. The present invention provides a method for manufacturing a zinc anode, a zinc anode manufactured using the same, and a zinc ion battery including the same.

[0028]

[0029] Figure 1 is a schematic diagram illustrating a method for manufacturing a zinc anode according to an embodiment of the present invention.

[0030] FIG. 2 is a schematic diagram comparing the zinc growth process of a conventional zinc anode and a zinc anode according to an embodiment of the present invention, and FIG. 3 is a schematic diagram specifically illustrating the zinc growth process in a zinc anode according to an embodiment of the present invention.

[0031] Figure 4 is a graph showing the results of X-ray diffraction analysis of a zinc anode according to Example 1.

[0032] Figure 5 is a graph showing the results of Raman spectroscopy analysis of a zinc anode according to Example 1.

[0033] Figure 6 is a graph showing the results of elemental identification by X-ray photoelectron spectroscopy of a zinc anode according to Example 1.

[0034] FIG. 7 is an image showing the results of a scanning electron microscope measurement of a zinc anode according to Example 1 before the operation of a zinc ion battery according to Example 2-1, and FIG. 8 is an image showing the results of a scanning electron microscope measurement of a zinc anode according to Example 1 after the operation of a zinc ion battery according to Example 2-1.

[0035] FIG. 9 is an image showing the results of energy dispersive X-ray spectroscopy analysis of a zinc anode according to Example 1 before operation of a zinc ion battery according to Example 2-1, and FIG. 10 is an image showing the results of cross-sectional scanning electron microscope measurement of a zinc anode according to Example 1 after operation of a zinc ion battery according to Example 2-1.

[0036] Fig. 11 is a graph showing the results of chronocurrent measurement of a zinc ion battery according to Comparative Example 2 and a zinc ion battery according to Example 2-1, Fig. 12 is a graph showing the results of rate characteristic evaluation, and Fig. 13 is a graph showing the results of stability evaluation.

[0037] FIG. 14 is an image showing the results of a scanning electron microscope measurement of a zinc anode according to Comparative Example 1 after battery operation of a zinc ion battery according to Comparative Example 2, FIG. 15 is an image showing the results of a scanning electron microscope measurement of a zinc anode according to Example 1 after battery operation of a zinc ion battery according to Example 2-1, and FIG. 16 is a digital photograph showing the zinc anode according to Comparative Example 1 and the zinc anode according to Example 1 after battery operation.

[0038] FIG. 17 is a graph showing the results of X-ray diffraction analysis of a zinc anode according to Example 1 after operation of a zinc ion battery according to Example 2-1, and FIG. 18 is a graph showing the existence ratio of (002) to (101) according to the results of X-ray diffraction analysis of FIG. 17.

[0039] Fig. 19 is a graph showing the results of cyclic current measurement of a zinc ion battery according to Comparative Example 2 and a zinc ion battery according to Example 2-2, and Fig. 20 is a graph showing the results of electrochemical impedance spectroscopy measurement.

[0040] Fig. 21 is a graph showing the results of rate characteristic evaluation of a zinc ion battery according to Comparative Example 2 and a zinc ion battery according to Example 2-2, and Fig. 22 is a graph showing the results of stability evaluation.

[0041]

[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings and the contents described in the attached drawings, but the present invention is not limited or restricted by the embodiments.

[0043] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, the singular includes the plural unless specifically stated otherwise. The terms "comprises" and / or "comprising" as used herein do not exclude the presence or addition of one or more other components or steps.

[0044] The terms “embodiment,” “example,” “aspect,” “example,” and the like as used herein are not to be construed as implying that any aspect or design described is better or advantageous over other aspects or designs.

[0045] Also, the term 'or' implies an inclusive or rather than an exclusive or. That is, unless stated otherwise or clear from context, the expression 'x utilizes a or b' means any one of the natural inclusive permutations.

[0046] Additionally, as used in this specification and claims, the singular forms “a” or “an” should generally be construed to mean “one or more” unless otherwise indicated or clear from the context to be in the singular form.

[0047] The terms used in the following description have been selected as common and universal in the relevant technical fields. However, other terms may be used depending on technological developments and / or changes, customs, and the preferences of technicians. Therefore, the terms used in the following description should not be construed as limiting the technical concepts, but rather as exemplary terms used to describe the embodiments.

[0048] Additionally, in certain cases, the applicant may arbitrarily select terms, in which case their detailed meanings will be described in the relevant description. Therefore, the terms used in the following description should be understood not simply as names, but based on their inherent meaning and the overall context of the specification.

[0049] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0050] Meanwhile, when describing the present invention, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted. Furthermore, the terminology used in this specification is intended to appropriately express embodiments of the present invention and may vary depending on the intent of the user or operator, or the customary practices in the field to which the present invention pertains. Therefore, the definitions of these terms should be based on the contents throughout this specification.

[0051]

[0052] Figure 1 is a schematic diagram illustrating a method for manufacturing a zinc anode according to an embodiment of the present invention.

[0053] A method for manufacturing a zinc anode according to an embodiment of the present invention includes a step (S110) of preparing a hexagonal boron nitride solution by mixing hexagonal boron nitride (e.g., bulk hexagonal boron nitride, 110), a binder polymer, and a solvent, and a step (S120) of preparing a zinc anode by spraying the hexagonal boron nitride solution onto a zinc foil (120), wherein the zinc anode includes hexagonal boron nitride scattered on the zinc foil (120).

[0054] Therefore, the method for manufacturing a zinc anode according to an embodiment of the present invention is to manufacture a zinc anode in which hexagonal boron nitride (110) is diagonally erected at regular intervals on a zinc foil (120) by spraying hexagonal boron nitride (110) on a zinc foil (120) through a spraying process, and when this is applied to a zinc ion battery, the stability of the zinc ion battery can be improved by blocking the two-dimensional diffusion path of zinc ions during zinc deposition and suppressing the growth of zinc dendrites.

[0055] First, a method for manufacturing a zinc anode according to an embodiment of the present invention includes a step (S110) of manufacturing a hexagonal boron nitride solution by mixing hexagonal boron nitride (e.g., bulk hexagonal boron nitride, 110), a binder polymer, and a solvent.

[0056] Hexagonal boron nitride (110) has a form in which nitrogen and boron are bonded in a hexagonal shape and are stacked in multiple layers, and thus has very high electrical resistance and chemical stability. Therefore, hexagonal boron nitride (110) has the advantage of not easily causing charging or chemical reactions even when voltage is applied to it due to these characteristics.

[0057] Hexagonal boron nitride (110) may have a bulk phase.

[0058] Hexagonal boron nitride (e.g., bulk hexagonal boron nitride, 110) can be 10 wt% to 20 wt% with respect to 100 wt% of the hexagonal boron nitride solution. If the hexagonal boron nitride (e.g., bulk hexagonal boron nitride, 110) is less than 10 wt%, the viscosity of the solution is too low, so there is a problem that the hexagonal boron nitride clumps during the drying process, and if it exceeds 20 wt%, the viscosity of the solution is too high, so there is a problem that the hexagonal boron nitride clumps during the coating process.

[0059] The binder polymer can act as an adhesive by forming van der Waals bonds between the hexagonal boron atoms.

[0060] The binder polymer may be 1 to 2 wt% based on 100 wt% of the hexagonal boron nitride solution. If the binder polymer is less than 1 wt%, there is a problem of insufficient adhesive strength, and if it exceeds 2 wt%, there is a problem of hindering the diffusion of zinc ions.

[0061] The binder polymer may include at least one of polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (poly(1,1,2,2-tetrafluoroethylene); PTFE).

[0062] The solvent may include at least one of N-methyl-2-pyrrolidone (hereinafter referred to as NMP), ethanol, and isopropyl alcohol.

[0063] Finally, the method for manufacturing a zinc anode according to an embodiment of the present invention proceeds with a step (S120) of manufacturing a zinc anode by spraying a hexagonal boron nitride solution on a zinc foil (120).

[0064] Therefore, the method for manufacturing a zinc anode according to an embodiment of the present invention can form a commercialized bulk hexagonal boron nitride (110) on a zinc foil (120) in a quick and simple process using spray coating.

[0065] The thickness of the zinc foil (120) can be 25 micrometers to 100 micrometers. If the thickness of the zinc foil (120) is less than 25 micrometers, there is a problem of holes being formed, and if it exceeds 100 micrometers, there is a problem in assembling the coin cell.

[0066] Hexagonal boron nitride (110) can be sprayed onto a zinc foil (120) through a compressed air spray process.

[0067] Hexagonal boron nitride (110) can be randomly scattered on a zinc foil (120).

[0068] The compressed air spray process can spray hexagonal boron nitride (110) on zinc foil (120) by putting a hexagonal boron nitride solution into a spray gun and changing the solution into fine particles with compressed air.

[0069] The spraying time of the hexagonal boron nitride solution can be 4 to 12 seconds. If the spraying time of the hexagonal boron nitride solution is less than 4 seconds, there is a problem that the scattered hexagonal boron nitride (110) does not effectively limit the two-dimensional diffusion of zinc ions, and if it exceeds 12 seconds, there is a problem that the hexagonal boron nitride (110) interferes with the three-dimensional diffusion of zinc ions.

[0070] The injection pressure of the hexagonal boron nitride solution can be 200 MPa to 400 MPa. If the injection pressure of the hexagonal boron nitride solution is less than 200 MPa, there is a problem that the solution is not evenly spread, and if it exceeds 400 MPa, there is a problem that too much solution is injected.

[0071] The step (S120) of manufacturing a zinc anode by spraying a hexagonal boron nitride solution on a zinc foil (120) can be performed by evenly spraying hexagonal boron nitride (110) on the entire surface of the zinc foil (120).

[0072] According to an embodiment, a method for manufacturing a zinc anode according to an embodiment of the present invention may further include a step (S120) of manufacturing a zinc anode by spraying a hexagonal boron nitride solution on a zinc foil (120), and then a step (S130) of heat-treating the boron nitride solution sprayed on the zinc foil (120).

[0073] The heat treatment step (S130) disperses the hexagonal boron nitride solution (e.g., compressed air spray process) and then rapidly dries the hexagonal boron nitride solution at the heat treatment temperature, so that the hexagonal boron nitride (110) can be solidified into the shape immediately after the spraying process (e.g., spray process) by the binder polymer.

[0074] For example, the heat treatment temperature of the heat treatment may be 120 ℃.

[0075] A zinc anode according to an embodiment of the present invention can be manufactured using a method for manufacturing a zinc anode according to an embodiment of the present invention.

[0076] Therefore, the method for manufacturing a zinc anode according to an embodiment of the present invention can significantly improve the stability and discharge capacity retention of a zinc ion battery, and if this is applied to a large-capacity energy storage facility, it can lower the unit cost of an eco-friendly renewable energy power generation facility and increase the proportion of renewable energy power generation.

[0077] The zinc anode according to an embodiment of the present invention is described in detail in FIGS. 2 and 3 below.

[0078]

[0079] FIG. 2 is a schematic diagram comparing the zinc growth process of a conventional zinc anode and a zinc anode according to an embodiment of the present invention, and FIG. 3 is a schematic diagram specifically illustrating the zinc growth process in a zinc anode according to an embodiment of the present invention.

[0080] A zinc anode (100) according to an embodiment of the present invention includes a zinc foil (120) and hexagonal boron nitride (110) scattered on the zinc foil (120). At this time, the hexagonal boron nitride (110) may be fixed to the zinc foil (120) by a binder polymer (e.g., PVDF) so as to be bonded at an angle with respect to the zinc foil (120) without being detached or laid down.

[0081] A zinc anode (100) according to an embodiment of the present invention can grow zinc three-dimensionally by hexagonal boron nitride (110).

[0082] Hexagonal boron nitride (110) has a form in which nitrogen and boron are bonded in a hexagonal shape and are stacked in multiple layers, and thus has very high electrical resistance and chemical stability. Therefore, hexagonal boron nitride (110) has the advantage of not easily causing charging or chemical reactions even when voltage is applied to it due to these characteristics.

[0083] Therefore, when a zinc ion battery is charged, hexagonal boron nitride (110) is electrochemically inactive even when the zinc anode is negatively charged. This property allows for control of the shape of zinc electrically deposited on the zinc anode.

[0084] During electrodeposition, the diffusion path of zinc ions can be divided into two-dimensional and three-dimensional.

[0085] For example, when two-dimensional diffusion occurs, as in a conventional zinc anode (10), the basal surface of the zinc dendrite increases, which can promote zinc dendrite growth.

[0086] Specifically, during the zinc deposition process, uncontrolled two-dimensional growth of zinc crystals may occur in a conventional zinc anode (10), which may result in the generation of defective grain boundaries, and in particular, protrusions are likely to be generated from defects in the defective grain boundaries.

[0087] In addition, when electrical charging is applied to a conventional zinc anode (10) for zinc deposition, a tip effect may occur in the protrusions on the surface of the conventional zinc anode (10). The tip effect means that a strong electric field is generated in a protrusion area with a large curvature.

[0088] Therefore, in the conventional zinc anode (10), a large dendritic structure can be formed as zinc is rapidly deposited on the protrusion where a strong electric field is generated.

[0089] On the other hand, in the zinc anode (100) according to an embodiment of the present invention, hexagonal boron nitride (110) scattered on a zinc foil (120) can act as electrochemically inactive barriers. These barriers change the surface of the zinc foil (120) from a two-dimensional structure to a three-dimensional structure, and by hindering the two-dimensional diffusion path of zinc ions, the basal surface of the dendrites is reduced, thereby inhibiting dendrite growth.

[0090] Specifically, in the zinc anode (100) according to an embodiment of the present invention, the hexagonal boron nitride (110) in the bulk acts as an electrochemically stable barrier, effectively suppressing two-dimensional growth of zinc crystals and inducing three-dimensional growth. Through this, in the zinc anode (100) according to an embodiment of the present invention, the occurrence of defective grain boundaries that may develop into zinc dendrites in the future is minimized, and a stable zinc structure (a zinc structure in which (002) is dominant and thus corrosion resistance and reversible zinc deposition / desorption are possible) is filled between the hexagonal boron nitride (110), thereby allowing the development of a flat surface structure.

[0091] Therefore, in the zinc anode (100) according to the embodiment of the present invention, during the zinc deposition process, the deposited zinc may include a high proportion of (002) crystal planes.

[0092] The higher the ratio of (002) of zinc deposited on the zinc anode (100) according to the embodiment of the present invention, the more electrochemically stable zinc structure can be deposited on the zinc anode (100) according to the embodiment of the present invention.

[0093] Additionally, the zinc anode (100) according to the embodiment of the present invention may be diagonally bonded with hexagonal boron nitride (110) at an angle on the zinc foil (120).

[0094] Therefore, in the zinc anode (100) according to the embodiment of the present invention, the hexagonal boron nitride (110) exists diagonally rather than parallel to the zinc foil (120), thereby blocking the two-dimensional diffusion path of zinc ions, thereby inducing zinc to grow flat, thereby suppressing the growth of the zinc resin.

[0095] The hexagonal boron nitride (110) may have a bonding angle (a) of 20° to 30° with respect to the surface of the zinc foil (120).

[0096] The zinc anode (100) according to an embodiment of the present invention can be applied to electrochemical devices such as a zinc ion battery, a zinc metal battery, a zinc air battery, a zinc bromine battery, a zinc manganese dioxide battery, a nickel zinc flow battery, a zinc secondary battery, or a zinc ion capacitor.

[0097] Preferably, the zinc anode (100) according to an embodiment of the present invention can be applied to a zinc ion battery, and a zinc ion battery including the zinc anode (100) according to an embodiment of the present invention will be described below.

[0098]

[0099] A zinc ion battery according to an embodiment of the present invention comprises a zinc anode according to an embodiment of the present invention, a cathode positioned opposite the zinc anode, a separator disposed between the zinc anode and the cathode, and an electrolyte filled between the zinc anode and the cathode, wherein the zinc anode comprises hexagonal boron nitride dispersed on a zinc foil.

[0100] Therefore, the zinc ion battery according to the embodiment of the present invention effectively suppresses the dendritic growth of the zinc anode, thereby delaying the occurrence of a short circuit compared to a conventional zinc anode (hereinafter referred to as Zn) and increasing active zinc, thereby improving energy storage capacity.

[0101] A zinc ion battery according to an embodiment of the present invention may include a zinc anode according to an embodiment of the present invention as a zinc anode.

[0102] Zinc anodes can be deposited by zinc ions via three-dimensional diffusion paths through hexagonal boron nitride.

[0103] The bonding angle of hexagonal boron nitride to the surface of the zinc foil can be 20° to 30°.

[0104] The cathode may be spaced apart from the zinc anode.

[0105] The cathode is activated carbon, α-MnO2, β-MnO2, γ-MnO 2, It may include at least one of δ-MnO2, MnO, Mn2O3, Mn3O4, V2O5, VO2, NaV3O8, LiV3O8, VS2, and polyaniline (PANI).

[0106] The separator may be disposed in the space between the zinc anode and cathode, thereby preventing short circuit between the zinc anode and cathode.

[0107] The separator can be used without any special restrictions as long as it has the function of physically separating the zinc anode and cathode, and it is particularly desirable to use one that has low resistance to ion movement of the electrolyte and excellent electrolyte moisture retention capacity.

[0108] The separator may be formed of a porous, non-conductive or insulating material. Accordingly, the separator may be formed of a porous polymer film, for example, a porous polymer film made of a polyolefin polymer including at least one of ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, and ethylene / methacrylate copolymer, either singly or in a laminated manner.

[0109] Additionally, the separator may be formed of a conventional porous nonwoven fabric, such as a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, or cellulose, but is not limited thereto.

[0110] The electrolyte may include an aqueous electrolyte, and the aqueous electrolyte may include an aqueous solvent and a metal salt. In this case, the aqueous solvent may include water.

[0111] In addition, the electrolyte may include a non-aqueous electrolyte, and the non-aqueous electrolyte may include a non-aqueous solvent and a metal salt. At this time, the non-aqueous solvent may include at least one of a nitrile solvent such as acetonitrile, propionitrile, and butyronitrile; a carbonate solvent such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylethyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, ethylene carbonate, propylene carbonate, and butylene carbonate; a ketone solvent such as acetone and cyclohexanone; an alcohol solvent such as methanol, ethanol, propanol, and isopropanol; an amide solvent such as N,N-dimethylformamide and N,N-dimethylacetamide; a carbamate solvent such as 3-methyl-2-oxazolidone; and a sulfur-containing compound solvent such as sulfolane, dimethyl sulfoxide, and 1,3-propanesultone.

[0112] The metal salt may include at least one of ZnSO4, Zn(NO3)2, Zn(CH3CO2)2, ZnCl2, ZnBr2, Zn[N(CF3SO2)2]2, Zn[N(C2F5SO2)2]2, Zn[N(C2F5SO2)(CF3SO2)]2, Zn(CF3SO3)2, Zn(C2F5SO3)2 and hydrates thereof.

[0113] A zinc ion battery according to an embodiment of the present invention can significantly improve the stability and capacity of a zinc ion battery in an inexpensive and practical manner, and if this is applied to a large-capacity energy storage facility, it can lower the unit cost of eco-friendly renewable energy generation and increase the proportion of renewable energy generation.

[0114]

[0115] Comparative Example 1: Zn

[0116] 0.025mm (99.95%, Goodfellow) zinc was used.

[0117]

[0118] Example 1: Zn SBN

[0119] Add 0.9 g of h-BN and 0.1 g of polyvinylidene fluoride (PVDF) as an adhesive to 5 mL of N-methyl-2-pyrrolidone (NMP), a solvent, and stir for 1 hour.

[0120] A zinc anode sprinkled with h-BN (hereinafter referred to as Zn SBN) is manufactured by spraying the stirred h-BN solution onto a zinc foil using a compressed air spray for 8 seconds.

[0121]

[0122] Comparative Example 2: Zn cell

[0123] A symmetric cell assembled in the sequence of (Zn / glass fiber separator / Zn) was fabricated using 2M ZnSO4 as an electrolyte.

[0124]

[0125] Example 2-1: Symmetric cell

[0126] A symmetric cell was fabricated using 2M ZnSO4 as an electrolyte, assembled in the sequence of (Zn SBN / glass fiber separator / Zn SBN).

[0127]

[0128] Example 2-2: Full cell

[0129] A full cell was fabricated using 2M ZnSO4 as an electrolyte, assembled in the sequence of (α-MnO2 / glass fiber separator / Zn SBN).

[0130]

[0131] Figure 4 is a graph showing the results of X-ray diffraction analysis of a zinc anode according to Example 1.

[0132] Referring to FIG. 4, it can be crystallographically confirmed that zinc and h-BN are present in the zinc anode according to Example 1.

[0133]

[0134] Figure 5 is a graph showing the results of Raman spectroscopy analysis of a zinc anode according to Example 1.

[0135] Referring to Figure 5, it can be seen that h-BN does not undergo any chemical change even after being scattered on zinc foil.

[0136]

[0137] Figure 6 is a graph showing the results of elemental identification by X-ray photoelectron spectroscopy of a zinc anode according to Example 1.

[0138] Referring to FIG. 6, the elements present in the zinc anode according to Example 1 were confirmed to include zinc, boron, and nitrogen.

[0139]

[0140] FIG. 7 is an image showing the results of a scanning electron microscope measurement of a zinc anode according to Example 1 before the operation of a zinc ion battery according to Example 2-1, and FIG. 8 is an image showing the results of a scanning electron microscope measurement of a zinc anode according to Example 1 after the operation of a zinc ion battery according to Example 2-1.

[0141] Referring to FIGS. 7 and 8, it can be seen that zinc is deposited flatly on the zinc anode according to Example 1.

[0142]

[0143] FIG. 9 is an image showing the results of energy dispersive X-ray spectroscopy analysis of a zinc anode according to Example 1 before battery operation of a zinc ion battery according to Example 2-1, and FIG. 10 is an image showing the results of cross-sectional scanning electron microscope measurement of a zinc anode according to Example 1 after battery operation of a zinc ion battery according to Example 2-1.

[0144] Referring to FIGS. 9 and 10, it can be seen that the zinc anode according to Example 1 has a flat zinc structure filled between h-BN.

[0145]

[0146] Fig. 11 is a graph showing the results of chronocurrent measurement of a zinc ion battery according to Comparative Example 2 and a zinc ion battery according to Example 2-1, Fig. 12 is a graph showing the results of rate characteristic evaluation, and Fig. 13 is a graph showing the results of stability evaluation.

[0147] Referring to Figure 11, the zinc anode according to Comparative Example 1 shows that the current density continues to increase with the deposition time, whereas the zinc anode according to Example 1 shows that the current density initially increases, and then decreases to 8 mA cm at around 260 seconds. -2 It can be seen that the current density converges.

[0148] This means that continuous two-dimensional zinc deposition occurs on the zinc anode according to Comparative Example 1, and that two-dimensional zinc deposition occurs only at the initial stage of deposition on the zinc anode according to Example 1.

[0149] Therefore, it can be seen that the zinc anode according to Example 1 suppresses the two-dimensional growth of zinc by bulk h-BN and induces three-dimensional growth.

[0150] Referring to Figure 12, the results of the constant current speed characteristic evaluation are 0.5 to 3 mA cm -2 It can be seen that the zinc anode according to Example 1 exhibits a lower zinc deposition / desorption overvoltage compared to the zinc anode according to Comparative Example 1 at a current density of .

[0151] Referring to Fig. 13, 3 mA cm -2 As a result of the constant current stability evaluation, it can be seen that the zinc anode according to Example 1 exhibits a lower zinc deposition / desorption overvoltage and maintains a stable cycle for approximately 10 times longer (500 hours) than the zinc anode according to Comparative Example 1.

[0152]

[0153] FIG. 14 is an image showing the results of a scanning electron microscope measurement of a zinc anode according to Comparative Example 1 after battery operation of a zinc ion battery according to Comparative Example 2, FIG. 15 is an image showing the results of a scanning electron microscope measurement of a zinc anode according to Example 1 after battery operation of a zinc ion battery according to Example 2-1, and FIG. 16 is a digital photograph showing the zinc anode according to Comparative Example 1 and the zinc anode according to Example 1 after battery operation.

[0154] Referring to FIGS. 14 to 16, it can be seen that a flatter and more uniform zinc structure is deposited on the zinc anode according to Example 1.

[0155]

[0156] FIG. 17 is a graph showing the results of X-ray diffraction analysis of a zinc anode according to Example 1 after operation of a zinc ion battery according to Example 2-1, and FIG. 18 is a graph showing the existence ratio of (002) to (101) according to the results of X-ray diffraction analysis of FIG. 17.

[0157] Referring to FIGS. 17 and 18, it can be seen that the zinc anode according to Example 1 has more (002) in the deposited zinc compared to the zinc anode according to Comparative Example 1.

[0158] (002) has excellent corrosion resistance, is less reactive with electrolytes, and more reversible zinc deposition / desorption can occur compared to other surfaces.

[0159]

[0160] Fig. 19 is a graph showing the results of cyclic current measurement of a zinc ion battery according to Comparative Example 2 and a zinc ion battery according to Example 2-2, and Fig. 20 is a graph showing the results of electrochemical impedance spectroscopy measurement.

[0161] Referring to FIG. 19, it can be seen that the zinc ion battery according to Example 2-2 has a higher capacitance and a lower oxidation / reduction overvoltage than the zinc ion battery according to Comparative Example 2.

[0162] And referring to FIG. 20, the zinc ion battery according to Example 2-2 showed a sharper and smaller semicircle in the Nyquist plot and a larger slope of the straight line section compared to the zinc ion battery according to Comparative Example 2. This means that the electrochemical reaction of the full cell assembled with the zinc anode according to Example 1 was faster and it had lower charge transfer resistance and high ion diffusion coefficient characteristics.

[0163]

[0164] Fig. 21 is a graph showing the results of rate characteristic evaluation of a zinc ion battery according to Comparative Example 2 and a zinc ion battery according to Example 2-2, and Fig. 22 is a graph showing the results of stability evaluation.

[0165] Figures 21 and 22 show the electrochemical characteristics of a zinc ion battery according to Example 2-2, measured using a constant current charge / discharge method.

[0166] Referring to FIGS. 21 and 22, it can be seen that the zinc ion battery according to Example 2-2, which is a full cell assembled with the zinc anode according to Example 1, is superior in terms of capacity and discharge capacity retention compared to the zinc anode according to Comparative Example 1 in the rate characteristic evaluation and stability evaluation.

[0167]

[0168] Although the present invention has been described with reference to limited embodiments and drawings, it is not limited to the embodiments described above, and those skilled in the art will appreciate that various modifications and variations may be made based on this disclosure. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the following claims but also by equivalents thereof.

Claims

1. A step of preparing a hexagonal boron nitride solution by mixing hexagonal boron nitride, a binder polymer, and a solvent; and A step of manufacturing a zinc anode by spraying the above hexagonal boron nitride solution on a zinc foil; Including, A method for manufacturing a zinc anode, characterized in that the zinc anode comprises the hexagonal boron nitride scattered on the zinc foil.

2. In paragraph 1, A method for manufacturing a zinc anode, characterized in that the zinc anode is grown three-dimensionally by the hexagonal boron nitride.

3. In paragraph 1, A method for manufacturing a zinc anode, characterized in that the above hexagonal boron nitride has a bonding angle of 20° to 30° with respect to the surface of the zinc foil.

4. In paragraph 1, A method for manufacturing a zinc anode, characterized in that the hexagonal boron nitride is 10 to 20 wt% based on 100 wt% of the hexagonal boron nitride solution.

5. In paragraph 1, A method for manufacturing a zinc anode, characterized in that the binder polymer is present in an amount of 1 to 2 wt% based on 100 wt% of the hexagonal boron nitride solution.

6. In paragraph 1, A method for manufacturing a zinc anode, characterized in that the binder polymer comprises at least one of polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (poly(1,1,2,2-tetrafluoroethylene); PTFE).

7. In paragraph 1, A method for producing a zinc anode, characterized in that the solvent comprises at least one of N-methyl-2-pyrrolidone (hereinafter referred to as NMP), ethanol, and isopropyl alcohol.

8. In paragraph 1, A method for manufacturing a zinc anode, characterized in that the injection time of the above hexagonal boron nitride solution is 4 to 12 seconds.

9. Manufactured according to the method for manufacturing a zinc anode according to Article 1, zinc foil; and Hexagonal boron nitride scattered on the zinc foil; A zinc anode characterized by comprising:

10. In paragraph 9, The above zinc anode is a zinc anode characterized in that zinc is grown three-dimensionally by the above hexagonal boron nitride.

11. In paragraph 9, A zinc anode characterized in that the above hexagonal boron nitride has a bonding angle of 20° to 30° with respect to the surface of the zinc foil.

12. Zinc anode according to Article 9; A cathode positioned opposite the zinc anode; A separator disposed between the zinc anode and the cathode; and An electrolyte filled between the zinc anode and the cathode; Including, A zinc ion battery characterized in that the zinc anode comprises hexagonal boron nitride dispersed on a zinc foil.

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