Method for manufacturing electrolyte for manganese ion battery and the electrolyte manufactured thereby and manganese ion battery comprising the electrolyte

Abstract

A method for manufacturing an electrolyte for a manganese ion battery, an electrolyte manufactured thereby, and a manganese ion battery containing the same are provided. The method for manufacturing an electrolyte for a manganese ion battery involves reacting manganese(II) fluoride, boron trifluoride, and acetonitrile to form a manganese salt acetonitrile solvate in powder form, and then dissolving the solvate in an organic solvent to produce an electrolyte. By improving the solubility in organic solvents, various organic solvents can be applied, thereby enabling the effective production of a manganese ion battery.

Description

Technology Field

[0001] The present invention relates to a secondary battery, and more specifically, to a method for manufacturing an electrolyte for a manganese ion battery, an electrolyte manufactured thereby, and a manganese ion battery comprising the same. Background Technology

[0002] Recently, with the proliferation of portable electronic devices and electric vehicles, the utilization of large-capacity energy storage systems is expanding. Consequently, there is a demand for the development of rechargeable batteries capable of high energy density and lightweight design. Lithium (Li)-ion rechargeable batteries are primarily used due to their excellent energy density, long cycle life, and relatively light weight. These lithium-ion batteries consist of a negative electrode, a positive electrode, and an electrolyte, utilizing materials capable of lithium deintercalation and intercalation as the active materials for the negative and positive electrodes.

[0003] However, lithium-ion secondary batteries are based on flammable organic electrolytes, which pose risks such as overheating and ignition, and are expensive and have environmental hazards when disposed of, so research is being conducted on various secondary batteries to replace them. The problem to be solved

[0004] Manganese (Mn) is characterized by its low cost and good environmental suitability, but because it is susceptible to corrosion, conventional commercial manganese salts have limited solubility in organic solvents.

[0005] In addition, there were limitations in producing manganese ion batteries because crystal water is required to passivate the manganese anode.

[0006] To solve the aforementioned problems, the present invention aims to provide a method for manufacturing an electrolyte for a manganese ion battery that can easily form a manganese ion battery, an electrolyte manufactured thereby, and a manganese ion battery containing the same.

[0007] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0008] To achieve the above objective, one aspect of the present invention provides a method for manufacturing an electrolyte for a manganese ion battery comprising the steps of reacting manganese(II) fluoride, boron trifluoride, and acetonitrile to form a solvate of manganese salt in powder form, and dissolving the solvate of manganese salt in an organic solvent to form an electrolyte, wherein the solvate of manganese salt is the solvate of manganese salt having the following chemical formula 1.

[0009] [Chemical Formula 1]

[0010] Mn(BF4)2·4CH3CN

[0011] The step of forming the above manganese salt acetonitrile solvate may include the step of forming a mixture of the above manganese(II) fluoride, boron trifluoride, and acetonitrile; the step of heating the mixture to 80 to 90°C to form a reaction product; the step of cooling the reaction product and then filtering it to form a filtrate; and the step of removing the solvent and ether from the filtrate and then cooling it to crystallize it.

[0012] The above organic solvent may include one or more selected from acetonitrile, dimethyl sulfoxide, N,N-dimethyl acetamide, diethylene glycol dimethyl ether, formamide, N-methyl formamide, and N,N-dimethyl formamide.

[0013] Another aspect of the present invention provides an electrolyte for a manganese ion battery comprising an organic solvent and a manganese salt acetonitrile solvate dissolved in the organic solvent, wherein the manganese salt acetonitrile solvate is the following chemical formula 1.

[0014] [Chemical Formula 1]

[0015] Mn(BF4)2·4CH3CN

[0016] Another aspect of the present invention provides a manganese ion battery comprising a cathode, an anode, and an electrolyte disposed between the cathode and the anode, the electrolyte comprising an organic solvent and a manganese salt acetonitrile solvate dissolved in the organic solvent, wherein the manganese salt acetonitrile solvate is the following chemical formula 1.

[0017] [Chemical Formula 1]

[0018] Mn(BF4)2·4CH3CN

[0019] The above cathode may include one or more selected from manganese metal, manganese alloy, bismuth (Bi), tellurium (Te), and activated carbon.

[0020] The above-mentioned anode comprises an active material, and the active material may comprise one or more selected from vanadium oxide, manganese oxide, and Prussian blue analogue (PBA) particles. Effects of the invention

[0021] The method for manufacturing an electrolyte for a manganese ion battery according to the present invention allows for the easy production of an electrolyte for a manganese ion battery by forming a manganese salt acetonitrile solvate with improved solubility in an organic solvent and then dissolving it in an organic solvent.

[0022] In addition, the electrolyte for a manganese ion battery according to the present invention can be used with various negative or positive electrode materials, thereby enabling the effective production of various types of manganese ion batteries.

[0023] The technical effects of the present invention are not limited to those mentioned above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description below. Brief explanation of the drawing

[0024] FIG. 1 is a flowchart illustrating a method for manufacturing an electrolyte for a manganese ion battery according to one embodiment of the present invention. FIG. 2 is a structural formula of manganese salt according to one embodiment of the present invention. FIG. 3 is a schematic diagram showing the structure of a manganese ion battery according to one embodiment of the present invention. Figure 4 is a graph showing the cyclic voltammetry measurement results of manganese ion batteries according to Manufacturing Examples 2 and 3 of the present invention. FIGS. 5(a) and FIGS. 5(b) are graphs showing the charge-discharge curves of a manganese ion battery according to Manufacturing Example 2 of the present invention. Specific details for implementing the invention

[0025] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0026] While the present invention allows for various modifications and variations, specific embodiments are illustrated in the drawings and will be described in detail below. However, it is not intended to limit the invention to the particular forms disclosed, but rather the invention includes all modifications, equivalents, and substitutions consistent with the spirit of the invention as defined by the claims.

[0027] When an element such as a layer, region, or substrate is referred to as existing "on" another component, it can be understood that this exists directly on the other element, or that an intermediate element may exist between them.

[0028] Although terms such as first, second, etc., may be used to describe various elements, components, regions, layers, and / or regions, it will be understood that these elements, components, regions, layers, and / or regions should not be limited by these terms.

[0030] Method for manufacturing an electrolyte for a manganese ion battery

[0031] FIG. 1 is a flowchart illustrating a method for manufacturing an electrolyte for a manganese ion battery according to one embodiment of the present invention.

[0032] Referring to FIG. 1, a manganese (II) fluoride, boron trifluoride, and acetonitrile can be reacted to form a solvate of manganese salt in powder form (S100). Specifically, the solvate of manganese salt is composed of manganese ions and anions and can be obtained in the form of a solvate.

[0033] First, a mixture of the above manganese (II) fluoride, boron trifluoride, and acetonitrile can be formed.

[0034] The above manganese(II) fluoride (MnF2) is a compound composed of manganese and fluoride, and can be used in the form of a pink crystalline solid. The above manganese(II) fluoride can provide manganese ions constituting the above manganese salt.

[0035] The boron trifluoride may be provided from boron trifluoride diethyl etherate (BF3·O(C2H5)2). Boron trifluoride diethyl etherate is a compound in which tetrahedral boron (B) is bonded to a diethyl ether ligand and may be in the form of a colorless liquid. The boron trifluoride provided from the boron trifluoride diethyl etherate may react with the fluoride anion of the manganese (II) fluoride to form a tetrafluoroborate (BF4) anion.

[0036] The above acetonitrile (CH3CN) can be used in a colorless liquid form. The acetonitrile has a free electron pair on the nitrogen (N) atom and can form a complex with the manganese ion.

[0037] Next, the mixture can be heated to 80 to 90°C to form a reaction product. Specifically, the mixture can be heated to 80 to 85°C. The reaction product may be in a solution state. By heating to the above-described range to form the reaction product, the yield of the target manganese salt acetonitrile solvate can be increased.

[0038] Next, the above reactants may be cooled and then filtered to form a filtrate. This may be done to remove reaction residues and separate the manganese salt formed by the reaction. Cooling and filtration may be performed using conventional methods. Filtration may be performed in an inert atmosphere to suppress the formation of unnecessary reactions.

[0039] Next, the solvent and ether can be removed from the filtrate, and then cooled to crystallize. The filtrate can be heated at 80 to 85°C to remove excess solvent and ether contained in the filtrate. By cooling and crystallizing the filtrate from which the solvent and ether have been removed, a solvate of manganese salt in powder form can be formed.

[0040] The above manganese salt acetonitrile solvate may be a substance having the following chemical formula 1.

[0041] [Chemical Formula 1]

[0042] Mn(BF4)2·4CH3CN

[0043] FIG. 2 is a structural formula of a manganese salt acetonitrile solvate according to one embodiment of the present invention.

[0044] Referring to Chemical Formula 1 and FIG. 2, the manganese salt acetonitrile solvate may be formed by the reaction of the manganese (II) fluoride and the boron trifluoride to form a tetrafluoroborate (BF4) anion. The manganese ions provided from the manganese (II) fluoride may form a complex with the acetonitrile to form a manganese salt acetonitrile solvate having the structural formula shown in FIG. 2.

[0045] Referring to FIG. 1, the manganese salt acetonitrile solvate can be dissolved in an organic solvent to form an electrolyte (S200). That is, in order to use the manganese salt acetonitrile solvate powder formed in S100 as an electrolyte for a manganese ion battery, the manganese ion battery electrolyte can be formed by dissolving it in an organic solvent suitable for this purpose. The manganese salt acetonitrile solvate is dissolved in the organic solvent and forms manganese cations (Mn 2+ It can be dissociated into ).

[0046] The above organic solvent can act as a medium through which ions involved in the electrochemical reaction of the battery can move in the electrolyte for the manganese ion battery. The above organic solvent may be used alone or as a mixture of two or more types, and when two or more types are mixed, the mixing ratio can be appropriately adjusted according to the desired battery performance. Specifically, the above organic solvent may include one or more selected from acetonitrile, dimethyl sulfoxide, N,N-dimethyl acetamide, diethylene glycol dimethyl ether, formamide, N-methyl formamide, and N,N-dimethyl formamide. In this embodiment, acetonitrile was used.

[0047] The concentration of the above electrolyte may be 0.01 to 2.0 M. Specifically, the concentration of the above manganese salt solvate may be used within a concentration range of 0.15 M to 2.0 M. When the concentration of the above manganese salt solvate is formed within the above-described range, it can have appropriate ionic conductivity as an electrolyte for a manganese ion battery and exhibit excellent electrolyte performance. If it falls outside the above-described range, precipitates may form or the mobility of manganese ions may decrease due to increased viscosity, which may degrade the charge and discharge characteristics of the battery.

[0049] Electrolyte for manganese-ion batteries

[0050] Another aspect of the present invention may provide an electrolyte for a manganese ion battery. The electrolyte for a manganese ion battery may be manufactured according to the method for manufacturing an electrolyte for a manganese ion battery described above.

[0051] Specifically, the electrolyte for the manganese ion battery may comprise an organic solvent and a manganese salt acetonitrile solvate dissolved in the organic solvent. In this case, the manganese salt acetonitrile solvate may be a substance having the following chemical formula 1.

[0052] [Chemical Formula 1]

[0053] Mn(BF4)2·4CH3CN

[0054] The above manganese salt acetonitrile solvate is prepared in the method for manufacturing an electrolyte for a manganese ion battery described above, and for a description of the above manganese salt acetonitrile solvate, refer to the above description.

[0055] The above manganese salt acetonitrile solvate is dissolved in the organic solvent to form manganese cations (Mn 2+ It can be dissociated into ).

[0056] The above organic solvent can act as a medium through which ions involved in the electrochemical reaction of the battery can move in the electrolyte for the manganese ion battery. Specifically, the above organic solvent may include one or more selected from acetonitrile, dimethyl sulfoxide, N,N-dimethyl acetamide, diethylene glycol dimethyl ether, formamide, N-methyl formamide, and N,N-dimethyl formamide.

[0057] The concentration of the above electrolyte may be 0.01 to 2.0 M. Specifically, the concentration of the above manganese salt solvate may be used in a concentration range of 0.15 M to 2.0 M. By forming it within the concentration range described above, ionic conductivity suitable for use as an electrolyte in a manganese ion battery can be achieved, thereby improving the performance of the battery.

[0058] According to the example, the electrolyte for the manganese ion battery comprising the manganese salt acetonitrile solvate may additionally include an additive. The additive may include at least one selected from fluoroethylene carbonate (FEC) and 1,4-diazabicyclo[2,2,2]octane (DABCO). The fluoroethylene carbonate (FEC) and the DABCO may decompose during the charge-discharge cycle of the battery to form a polymer coating layer (or SEI layer) on the surface of the negative electrode and serve to prevent oxidation of the manganese metal used as the negative electrode.

[0059] The electrolyte for a manganese ion battery comprising the above-mentioned manganese salt acetonitrile solvate can exhibit high electrochemical stability. Accordingly, the electrolyte for a manganese ion battery of the present invention can be utilized in various forms of manganese ion batteries or non-aqueous secondary batteries, including coin cells and pouch cells.

[0061] manganese ion battery

[0062] Another aspect of the present invention provides a manganese ion battery. The manganese ion battery may refer to a battery that uses manganese ions as a charge transfer material. The manganese ion battery may include an electrolyte prepared in the method for preparing an electrolyte for a manganese ion battery described above.

[0063] FIG. 3 is a schematic diagram showing a manganese ion battery according to one embodiment of the present invention.

[0064] Referring to FIG. 3, the manganese ion battery (100) may be provided with a negative electrode (10), a positive electrode (20), and an electrolyte disposed between the negative electrode (10) and the positive electrode (20), comprising an organic solvent and a manganese salt acetonitrile solvate dissolved in the organic solvent.

[0065] At this time, the above manganese salt acetonitrile solvate may be a substance having the following chemical formula 1.

[0066] [Chemical Formula 1]

[0067] Mn(BF4)2·4CH3CN

[0068] The above manganese salt acetonitrile solvate is prepared in the method for manufacturing an electrolyte for a manganese ion battery described above, and for a description of the above manganese salt acetonitrile solvate, refer to the above description.

[0069] The above cathode (10) may include one or more selected from manganese metal, manganese alloy, bismuth (Bi), tellurium (Te), and activated carbon.

[0070] Standard electrode potential of manganese (Mn 2+ +2e -→Mn) is -1.185V (vs. SHE), the theoretical mass specific capacity is 975mAh / g, and the theoretical volume specific capacity is 7,083mAh / cm³ 2 As such, it has the second highest volumetric capacity after aluminum (Al). Therefore, manganese metal can be used as an electrode material for batteries that require a large capacity storage capacity in a limited volume. In addition, since the manganese metal is significantly cheaper than lithium metal, it can solve the problem of unstable supply of lithium metal, and since it has lower reactivity than lithium metal, it can be a relatively stable material.

[0071] In one embodiment, the cathode (10) may be a manganese metal in the form of a foil or a flake. The thickness of the manganese metal may be 100 μm to 1000 μm, specifically 200 μm to 500 μm, but is not limited thereto.

[0072] In another embodiment, the cathode (10) may use a manganese alloy. The manganese alloy may be an alloy composed of manganese and at least one metal selected from Al, Si, Fe, Li, Mg, Cu, Ge, Co, Cr, Ni, and Sn.

[0073] The above-mentioned cathode (10) may include a Solid Electrolyte Interface (SEI) layer formed by the decomposition reaction of an additive and / or an organic solvent on its surface. As the decomposition reaction of the electrolyte occurs on the surface of the cathode (10), the manganese metal may be oxidized to form manganese oxide; therefore, it may be important to form an SEI layer that performs the role of preventing the oxidation of the manganese metal in order to prevent this.

[0074] According to the examples, an additive may be additionally included in the electrolyte to form the SEI layer. Specifically, the additive may be at least one selected from fluoroethylene carbonate (FEC) and 1,4-diazabicyclo[2,2,2]octane (DABCO), but is not limited thereto. As the additive, fluoroethylene carbonate (FEC) may serve to form the SEI layer, for example, a Mn-F-based SEI layer, and 1,4-diazabicyclo[2,2,2]octane (DABCO) may serve as a surfactant that prevents the oxidation of manganese and facilitates the plating / stripping of manganese ions.

[0075] When fluoroethylene carbonate (FEC) is used as the above additive, it may be added in an amount of 0.5 to 5 wt% relative to the total mass of the electrolyte. In one embodiment, the fluoroethylene carbonate (FEC) additive may be added in an amount of 2 wt% relative to the total mass of the electrolyte, but is not limited thereto.

[0076] In addition, when 1,4-diazabicyclo[2,2,2]octane (DABCO) is used as the additive, it can be added in an amount of 1 to 500 ppmw relative to the total mass of the electrolyte. In one embodiment, the 1,4-diazabicyclo[2,2,2]octane (DABCO) additive can be added in an amount of 200 ppmw relative to the total mass of the electrolyte, but is not limited thereto.

[0077] The anode (20) may be formed by a slurry containing an active material, a binder, and a conductive material being formed on a current collector. The active material of the anode (20) may include one or more selected from vanadium oxide, manganese oxide, and Prussian blue analogue (PBA) particles.

[0078] Specifically, the vanadium oxide may include at least one selected from VO2(B), V2O3, V2O5, and NaV3O8. In particular, manganese ions (Mn⁻¹) which are divalent ions 2+ Since ) is utilized as a charge carrier, it may be desirable to use a vanadium-based cathode active material having a wide oxidation state range from 2 to 5. In addition, because this has a large crystal lattice size, manganese cations (Mn) during the charging and discharging process of the battery 2+ Insertion and removal of ) can be easy.

[0079] The above manganese oxide is manganese dioxide (MnO2) or K x It may include at least one selected from MnO2 (where x is 0.3 or 0.45).

[0080] The above Prussian blue analogue is also called metal hexacyanometallates and refers to a group of derivative materials in which iron ions are replaced by other metal ions, based on a structure (Prussian blue) formed through the chemical bonding of iron and cyano (CN) groups as a matrix, as a type of metal-organic framework. When the positive electrode active material is composed of the above Prussian blue analogue, the mixing of cations within the battery in conventional batteries is suppressed, thereby stabilizing the charge-discharge structure of the battery and further enhancing battery performance. Specifically, the above Prussian blue analogue (PBA) particles may be KCo[Fe(CN)6]. The above Prussian blue analogue particles may be those manufactured by conventional methods.

[0081] In this embodiment, VO2(B) was used as the active material of the anode (20). This may be formed by the solvothermal synthesis of V2O5 and ethanol, but is not limited thereto.

[0082] The conductive material mentioned above may be used without limitation as long as it is generally available in the industry, for example, artificial graphite, natural graphite, carbon black, acetylene black, Ketjen black, Denka black, thermal black, channel black, carbon nanofibers, carbon nanotubes, metal fibers, or mixtures thereof. In one embodiment, the conductive material may be a mixture of Ketjen black and super P in a 1:1 mass ratio, but is not limited thereto.

[0083] The above binder may be used without limitation as long as it is generally available in the industry, for example, polyvinylidene fluoride (PVdF), copolymer of polyhexafluoropropylene-polyvinylidene fluoride (PVdF / HFP), poly(vinyl acetate), polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyvinylpyridine, alkylated polyethylene oxide, polyvinyl ether, poly(methyl methacrylate), poly(ethyl acrylate), polytetrafluoroethylene (PTFE), polyvinyl chloride, polyacrylonitrile, styrene-butadiene rubber, acrylonitrile-butadiene rubber, fluororubber, ethylene-propylene-diene monomer (EPDM), sulfonated ethylene-propylene-diene monomer, carboxymethylcellulose (CMC), sodium carboxymethylcellulose, regenerated cellulose, starch, hydroxypropylcellulose, Tetrafluoroethylene or a mixture thereof may be used. In one embodiment, the binder may be sodium carboxymethylcellulose, but is not limited thereto.

[0084] As a solvent for forming a slurry containing the active material, binder, and conductive material of the anode (20), water-based solvents such as water, ethanol, and isopropyl alcohol (IPA), or organic solvents such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), and acetone may be used, and these solvents may be used alone or in a mixture of two or more. In one embodiment, water may be used as the solvent, but it is not limited thereto. The amount of solvent used may be adjusted to an appropriate viscosity capable of dissolving and dispersing the active material, binder, and conductive material, taking into account the coating thickness and manufacturing yield of the slurry.

[0085] A slurry comprising the active material, binder, and conductive material of the anode (20) can be formed by mixing them in a certain ratio to maintain viscosity and processability. The ratio of the active material, binder, and conductive material may be 8:1:1 by mass, but is not limited thereto.

[0086] The anode (20) may be formed on the current collector layer with a thickness of 50 to 200 μm, specifically with a thickness of 80 to 120 μm. In one embodiment, the anode (20) may be formed on the current collector layer with a thickness of 100 μm, but is not limited thereto.

[0087] The separator (30) can be positioned between the cathode (10) and the anode (20) to electrically insulate the electrodes. Additionally, the separator (30) is sufficiently impregnated with the electrolyte (40) liquid, and due to its porous interior, it is possible for manganese ions to move from the cathode to the anode and from the anode to the cathode. As the separator (30), a conventional porous polymer film used as a separator, such as a porous polymer film made of a polyolefin-based polymer like ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / methacrylate copolymer, polyvinyl alcohol, etc., can be used alone or in a laminated form, or a conventional porous nonwoven fabric, such as glass fiber, carboxymethyl cellulose, polyethylene terephthalate fiber, etc., can be used. In one embodiment, the separator (30) may be made of glass fiber with a thickness of 10 to 500 μm, but is not limited thereto.

[0088] The above-mentioned cathode (10) and the above-mentioned anode (30) may additionally include a current collector layer (not shown) on opposite sides facing each other. The current collector layer is not particularly limited as long as it is conductive without causing chemical changes in the battery, and any conductive material to which the slurry of the active material can easily adhere and which is non-reactive within the voltage range of the battery may be used. Non-limiting examples of the current collector layer include carbon paper or titanium (Ti) with a thickness of 3 to 500 μm, but are not limited thereto.

[0089] Hereinafter, preferred experimental examples are presented to aid in understanding the present invention. However, the following experimental examples are intended only to aid in understanding the present invention, and the present invention is not limited by the following experimental examples.

[0091] Preparation Example 1: Preparation of electrolyte for manganese ion battery

[0092] 1 g of manganese(II) fluoride (MnF2), 2.7 ml of boron trifluoride diethyl etherate (BF3·O(C2H5)2), and 7 ml of acetonitrile (CH3CN) were added to a two-necked flask equipped with a condenser and a gas outlet under a dry argon (Ar) atmosphere and mixed. The mixture was heated at 85°C while continuously stirring to allow the reaction to proceed. At the end of the reaction, the evolving of diethyl ether stopped. The reaction mixture was then cooled and filtered under an inert atmosphere. Subsequently, the filtrate was heated under a vacuum at 80°C to remove excess solvent and ether. When cooled under an argon (Ar) atmosphere, it crystallized to form a white powder of manganese salt acetonitrile solvate having the chemical formula Mn(BF4)2·4CH3CN.

[0093] Next, the formed manganese salt acetonitrile solvate powder was dissolved in acetonitrile, an organic solvent, to form an electrolyte. At this time, the electrolyte was divided into multiple specimens and prepared such that the concentration (M) of the electrolyte was 0.01, 0.02, 0.075, 0.15, 0.50, 1.00, 1.50, and 2.00.

[0095] Preparation Example 2: Preparation of a manganese ion battery

[0096] (1) Manufacturing of the cathode

[0097] 1.00 g of vanadium pentoxide (V2O5) was dispersed in 35 ml of ethanol, and vanadium dioxide (VO2) was synthesized by performing solvothermal synthesis at 150°C for 12 hours. Afterward, the mixture was filtered using 500 ml of ethanol to remove reaction by-products, and the solid was dried at 80°C for 12 hours to obtain VO2 active material powder.

[0098] An anode slurry was prepared by mixing the obtained vanadium dioxide (VO2) powder, acetylene black, and polyvinylidene fluoride (PVDF) in an 8:1:1 ratio, followed by mixing in N-methyl-2-pyrrolidone. Subsequently, the anode slurry was cast onto a carbon cloth to a thickness of 100 µm and dried at 100°C for approximately 12 hours to produce an anode. The anode slurry contained 2 to 4 mg / cm² of the carbon cloth. 2 The active substance of was included.

[0099] (2) Preparation of the anode

[0100] Activated carbon prepared using acetylene black and polyvinylidene fluoride (PVDF) was used as the cathode.

[0101] (3) Manufacturing of batteries

[0102] The anode of (1), the glass-fiber separator, and the cathode of (2) were stacked in sequence to assemble a battery in the form of a coin (R2032). Afterward, the electrolyte prepared in Manufacturing Example 1 was injected into the assembled battery. All manufacturing processes were performed inside a glove box.

[0104] Preparation Example 3: Manganese ion battery equipped with titanium (Ti) as a positive current collector

[0105] A manganese ion battery was manufactured in the same manner as in Manufacturing Example 2, except that the anode slurry was formed on a titanium (Ti) substrate during the manufacturing of the anode in Manufacturing Example 2.

[0107] Experimental Example 1: Measurement of Electrical Conductivity of Electrolytes

[0108] The electrical conductivity of the manganese salt solvate prepared in Preparation Example 1 above was measured. Conductivity was measured using electrochemical impedance spectroscopy with a Biologic VMP 3 potentiostat. For this purpose, the electrical resistance of the tested electrolyte was measured in a cylindrical cell with two coaxial cylindrical gold-coated stainless steel electrodes and compared with the electrical resistance of a standard 0.1M KCl aqueous solution.

[0109] Table 1 below shows the results of measuring electrical conductivity according to the concentration of the electrolyte according to Preparation Example 1.

[0110] Electrolyte concentration (M) Electrical conductivity (σ / mS·cm) -1 ) 0.01 2.9 0.02 3.0 0.075 12.5 0.15 17.8 0.50 30.0 1.00 30.7 1.50 22.6 2.00 17.2

[0111] Experimental Example 2: Measurement of Electrical Characteristics of a Battery Using Cyclic Volammetry

[0112] The electrical characteristics of the manganese ion batteries prepared in Preparation Examples 2 and 3 were measured using cyclic voltammetry. At this time, the scan rate was 0.5 mV / s. The carbon fiber current collector was tested at 0 to 2 V, while the titanium foil was tested between -0.5 and 3 V. Electrochemical data were recorded using a Biologic VMP 3 potentiostat at 25°C.

[0113] Figure 4 is a graph showing the cyclic voltammetry measurement results of the manganese ion batteries of Manufacturing Example 2 and Manufacturing Example 3 according to one embodiment of the present invention.

[0114] Referring to Figure 4, it can be seen that the electrolyte for the manganese ion battery exhibits overall high electrochemical stability.

[0116] Experimental Example 3: Measurement of Constant Current Charge-Discharge Characteristics of a Battery

[0117] The constant current charge-discharge profile of the manganese-ion battery of Preparation Example 2 was measured. The battery cell was tested by constant current charge-discharge at a current density of 50 mA / g. The experiment was performed at 25°C using WonaTech charge.

[0119] FIGS. 5(a) and FIGS. 5(b) are graphs showing the constant current charging and discharging measurement results of the manganese ion battery of Manufacturing Example 2 according to one embodiment of the present invention.

[0120] Referring to FIGS. 5(a) and 5(b), it can be seen that the capacity is maintained at 70% or more even after 200 charge-discharge cycles.

[0121] Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various modifications and changes are possible by those skilled in the art within the technical spirit and scope of the present invention. Explanation of the symbols

[0122] 100: Manganese ion battery 10: Negative electrode 20: Anode 30: Separator 40: Electrolytes

Claims

Claim 1 A method for manufacturing an electrolyte for a manganese ion battery comprising: a step of reacting manganese(II) fluoride (MnF2), boron trifluoride (BF3), and acetonitrile to form a solvate of manganese salt in powder form; and a step of dissolving the solvate of manganese salt in an organic solvent to form an electrolyte; wherein the step of forming the solvate of manganese salt comprises: a step of forming a mixture of the manganese(II) fluoride (MnF2), boron trifluoride (BF3), and acetonitrile; a step of heating the mixture to 80 to 90°C to form a reaction product; a step of cooling the reaction product and filtering it to form a filtrate; and a step of removing the solvent and ether from the filtrate and cooling it to crystallize, wherein the solvate of manganese salt is the solvate of manganese salt having the following chemical formula 1. [Chemical Formula 1] Mn(BF4)2·4CH3CN Claim 2 delete Claim 3 A method for preparing an electrolyte for a manganese ion battery according to claim 1, wherein the organic solvent comprises one or more selected from acetonitrile, dimethyl sulfoxide, N,N-dimethyl acetamide, diethylene glycol dimethyl ether, formamide, N-methyl formamide, and N,N-dimethyl formamide. Claim 4 An organic solvent; and a manganese salt acetonitrile solvate dissolved in the organic solvent; wherein the manganese salt acetonitrile solvate is formed by the steps of forming a mixture of manganese(II) fluoride (MnF2), boron trifluoride (BF3), and acetonitrile; heating the mixture to 80 to 90°C to form a reaction product; cooling the reaction product and filtering it to form a filtrate; removing the solvent and ether from the filtrate and cooling it to crystallize; and wherein the manganese salt acetonitrile solvate is an electrolyte for a manganese ion battery having the following chemical formula 1. [Chemical Formula 1] Mn(BF4)2·4CH3CN Claim 5 In claim 4, the organic solvent comprises one or more selected from acetonitrile, dimethyl sulfoxide, N,N-dimethyl acetamide, diethylene glycol dimethyl ether, formamide, N-methyl formamide, and N,N-dimethyl formamide, an electrolyte for a manganese ion battery. Claim 6 A manganese ion battery comprising: a negative electrode; a positive electrode; and an electrolyte disposed between the negative electrode and the positive electrode, the electrolyte comprising an organic solvent and a manganese salt acetonitrile solvate dissolved in the organic solvent; wherein the manganese salt acetonitrile solvate is formed by the steps of: forming a mixture of manganese(II) fluoride (MnF2), boron trifluoride (BF3), and acetonitrile; heating the mixture to 80 to 90°C to form a reaction product; cooling the reaction product and filtering it to form a filtrate; removing the solvent and ether from the filtrate and cooling it to crystallize; and wherein the manganese salt acetonitrile solvate is a manganese ion battery having the following chemical formula 1. [Chemical Formula 1] Mn(BF4)2·4CH3CN Claim 7 In claim 6, the cathode comprises one or more selected from manganese metal, manganese alloy, bismuth (Bi), tellurium (Te), and activated carbon, forming a manganese ion battery. Claim 8 In claim 6, the positive electrode comprises an active material, and the active material comprises one or more selected from vanadium oxide, manganese oxide, and Prussian blue analogue (PBA) particles, forming a manganese ion battery.

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