KR101847821B1 - Flow battery having excellent charge and discharge characteristics - Google Patents

Abstract

The present invention provides a flow cell in which a positive electrode current collector, a negative electrode current collector, and a separator disposed between the positive electrode current collector and the negative electrode current collector are supplied with a positive electrode electrolyte and a negative electrode electrolyte to charge and discharge, ₂ X _n anode electrolyte Fe (terpy) as a cathode active material (here, n is a natural number of 1 or 2, X is ^{_{SO 4 2-, Cl -, Br}} -, I -, F -, I 3 -, I 2 ^{_{F -, Br 2 F -,}} Cl 2 F -, I 2 Br -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 -, CF 3 SO 3 -, ( ^{_{CN) 2 N -, (CF}} 3 SO 2) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C -, CF 3 CO 2 -, C 3 F 7 CO 2 ^{- at} least one material selected from the group consisting of C ₂ O ₄ ^{2 -} and CH ₃ CO ₂ ^- ), wherein the cathode electrolyte comprises NaFe (EDTA) (ferric sodium ethylenediaminetetraacetate) as a negative electrode active material. The flow cell of the present invention has excellent charge and discharge characteristics.

Description

[0001] The present invention relates to a flow cell having excellent charge and discharge characteristics,

The present invention relates to a flow cell, and more particularly to a flow cell using a cathode active material containing Fe (terpy) ₂ X _n (where n is a natural number of 1 or 2 and X is an anion) sodium ethylenediaminetetraacetate) as a negative electrode active material.

A flow cell is an energy storage material that contains a redox pair capable of redox and is formed into a solution and accumulates or emits energy as it flows in the flow cell.

Flow cells are attracting attention as batteries suitable for large-capacity energy storage. However, since the energy density is low, a volume of 2 to 3 times larger than that of a lithium secondary battery is required.

The energy storage material of the flow cell which is currently commercialized generally uses aqueous vanadium ion, and also the hydrogen ion (H ⁺ ) is used as the electrolyte for the charge ion. Such a vanadium-based flow cell generates a voltage of about 1.2 V theoretically, and since it is an aqueous solution, the ion conductivity is high and the output is excellent and the safety is excellent because no flammable solvent is used. However, there is a drawback that the energy density that can be stored due to the low voltage is low. Flow cells store large energy for a long period of time, and because they are large-scale facilities, they are less space-constrained because they are building-type devices. However, the low energy density means a large-scale facility. This is a high energy density and contrasts with a lithium secondary battery applicable for storage in various applications.

The vanadium-based flow cell using the four oxidation states of vanadium maintains the life of the membrane for the longest, so it has good durability to use the battery for 10 to 20 years. However, since the voltage is low, the energy density is low as mentioned above, and the maximum output value is also lowered. In addition, since the vanadium-based flow cell is in a strongly acidic condition, the electrode may slowly corrode, shortening the service life and lowering the output.

Korean Patent Publication No. 10-1509581

SUMMARY OF THE INVENTION The present invention provides a flow cell having excellent charge and discharge characteristics.

The present invention provides a flow cell in which a positive electrode current collector, a negative electrode current collector, and a separator disposed between the positive electrode current collector and the negative electrode current collector are supplied with a positive electrode electrolyte and a negative electrode electrolyte to charge and discharge, ₂ X _n anode electrolyte Fe (terpy) as a cathode active material (here, n is a natural number of 1 or 2, X is ^{_{SO 4 2-, Cl -, Br}} -, I -, F -, I 3 -, I 2 ^{_{F -, Br 2 F -,}} Cl 2 F -, I 2 Br -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 -, CF 3 SO 3 -, ( ^{_{CN) 2 N -, (CF}} 3 SO 2) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C -, CF 3 CO 2 -, C 3 F 7 CO 2 ^{- at} least one material selected from the group consisting of C ₂ O ₄ ^{2 -} and CH ₃ CO ₂ ^- , and the negative electrode electrolyte solution comprises a ferrous sodium ethylenediaminetetraacetate (NaFe) (EDTA) as a negative electrode active material.

The electrolyte solution may further comprise a supporting electrolyte, wherein the supporting electrolyte comprises a cation and an anion, wherein the cation is a quaternary ammonium ion, a polymeric ammonium ion, a lithium ion , Sodium ion, hydrogen ion and potassium ion, and the anion is selected from the group consisting of Cl ^- , Br ^- , I ^- , F ^- , I ₃ ^- , I ₂ F ^- , Br ₂ F ^{- _{Cl 2 F -, I 2 Br}} -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 -, CF 3 SO 3 -, (CN) 2 N -, (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , CF ₃ CO ₂ ^- , C ₃ F ₇ CO ₂ ^- and CH ₃ CO ₂ ^- And may contain one or more selected anions. The supporting electrolyte preferably has a concentration of 0.01 to 5M.

The cathode active material preferably has a concentration of 0.0001 to 2.0M.

Wherein the anode active material has a concentration of 0.0001 to 2.0M.

The positive electrode electrolyte and the negative electrode electrolyte may include an aqueous solvent for dissociating the electrolyte.

The cathode current collector and the anode current collector may include a felt having electrical conductivity.

According to the flow cell of the present invention, the Fe (terpy) ₂ X _n (where, n is a natural number of 1 or 2, X is ^{_{SO 4 2-, Cl -, Br}} -, I -, F -, I 3 -, ^{_{I 2 F -, Br 2 F}} -, Cl 2 F -, I 2 Br -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 -, CF 3 SO 3 - ^{_{, (CN) 2 N -,}} (CF 3 SO 2) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C -, CF 3 CO 2 -, C 3 F 7 (EDTA) (ferric sodium ethylenediaminetetraacetate) is used as a positive electrode active material containing at least one selected from the group consisting of CO ₂ ^- C ₂ O ₄ ^{2 -} and CH ₃ CO ₂ ^- Discharge characteristics.

1 is a schematic view of a flow cell according to the present invention.
Figs. 2 to 4 are photographs of an experimental battery cell.
5 is a cross-sectional view illustrating a method of assembling a battery cell.
6 is a front view showing an outer case of the battery cell.
7 is a side view showing an outer case of the battery cell.
8 is a plan view showing an outer case of the battery cell.
9 is a front view showing a cover of the battery cell.
10 is a side view showing a cover of the battery cell.
11 is a plan view showing a cover of the battery cell.
12 is a graph showing electrochemical oxidation and reduction potentials measured as a result of measurement using an active material.
13 is a graph showing charge / discharge curves measured as a measurement result using an active material.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not. Wherein like reference numerals refer to like elements throughout.

A flow cell according to a preferred embodiment of the present invention is a flow cell comprising a positive electrode current collector, a negative current collector, and a separator disposed between the positive current collector and the negative current collector, Wherein the positive electrode active material is Fe (terpy) ₂ X _n (wherein n is a natural number of 1 or 2, and X is SO ₄ ^2- , Cl ^- , Br ^- , I ^- , F ^{_{-, I 3 -, I 2}} F -, Br 2 F -, Cl 2 F -, I 2 Br -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 - ^{_{, CF 3 SO 3 -, (}} CN) 2 N -, (CF 3 SO 2) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C -, CF 3 CO 2 ^- , C ₃ F ₇ CO ₂ ^- C ₂ O ₄ ^{2 -} and CH ₃ CO ₂ ^- ), and the negative electrode electrolyte contains NaFe (EDTA) (ferric sodium ethylenediaminetetraacetate) as the negative electrode active material do.

The electrolyte solution may further comprise a supporting electrolyte, wherein the supporting electrolyte comprises a cation and an anion, wherein the cation is a quaternary ammonium ion, a polymeric ammonium ion, a lithium ion , Sodium ion, hydrogen ion and potassium ion, and the anion is selected from the group consisting of Cl ^- , Br ^- , I ^- , F ^- , I ₃ ^- , I ₂ F ^- , Br ₂ F ^{- _{Cl 2 F -, I 2 Br}} -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 -, CF 3 SO 3 -, (CN) 2 N -, (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , CF ₃ CO ₂ ^- , C ₃ F ₇ CO ₂ ^- and CH ₃ CO ₂ ^- And may contain one or more selected anions. The supporting electrolyte preferably has a concentration of 0.01 to 5M.

The cathode active material preferably has a concentration of 0.0001 to 2.0M.

Wherein the anode active material has a concentration of 0.0001 to 2.0M.

The positive electrode electrolyte and the negative electrode electrolyte may include an aqueous solvent for dissociating the electrolyte.

The cathode current collector and the anode current collector may include a felt having electrical conductivity.

Hereinafter, a flow cell according to a preferred embodiment of the present invention will be described in more detail.

Flow cells are attracting attention as batteries suitable for large-capacity energy storage. However, since the energy density is low, a volume of 2 to 3 times larger than that of a lithium secondary battery is required. In order to improve the energy density, it is necessary to develop a redox pair as compared with a flow cell using a conventional aqueous solution.

The problem with the redox couple for nonaqueous solvents is low reactivity (low current) with low solubility. Low solubility and low current have a direct effect on the energy storage as well as on the cell output, thus acting as a direct barrier to the study of the redox couple for non-aqueous solvents.

In the present invention, Fe (terpy) ₂ X _n (where n is a natural number of 1 or 2, X is ^{_{SO 4 2-, Cl -, Br}} -, I -, F -, I 3 -, I 2 F -, ^{_{Br 2 F -, Cl 2 F}} -, I 2 Br -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 -, CF 3 SO 3 -, (CN) 2 ^{_{N -, (CF 3 SO 2}} ) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C -, CF 3 CO 2 -, C 3 F 7 CO 2 - C 2 O ₄ ^{2 -} and CH ₃ CO ₂ ^- ) and using an anode active material comprising NaFe (EDTA) (Ferric sodium ethylenediaminetetraacetate).

1 is a schematic view of a flow cell according to the present invention.

1, the flow cell includes a positive electrode current collector 110, a negative electrode current collector 120, a separator 130 disposed between the positive electrode collector 110 and the negative electrode collector 120, The positive electrode electrolyte 140 and the negative electrode electrolyte 150 are supplied and charged and discharged. The positive electrode current collector 110 and the negative electrode current collector 120 may be connected to a power supply via a wire.

The flow cell includes a cathode cell 115 including a cathode current collector 110 and a cathode electrolyte 140, a cathode cell 125 including a cathode current collector 120 and a cathode electrolyte 150, 115 and the cathode cell 125 and separates the ions. The anode cell 115, the cathode cell 125, and the separator 130 constitute a battery cell. The flow cell may be formed by connecting a plurality of such battery cells or by stacking them.

A first tank 155 for supplying the anode electrolyte 140 is connected to the anode cell 115 through the conduits 160 and 165. A second tank 170 for supplying the cathode electrolyte 150 is connected to the cathode cell 125 through the conduits 175 and 180. The conduit 160 may be provided with a pump (not shown) for circulating the anode electrolyte 140 and a conduit 175 may be provided with a pump (not shown) for circulating the cathode electrolyte 150.

The positive electrode electrolyte solution 140 embedded in the first tank 155 is supplied to the positive electrode cell 115 through the conduit 160 and the positive electrode electrolyte solution 140 supplied to the positive electrode cell 115 passes through the conduit 165 And is then introduced into the first tank 155. The cathode electrolyte 150 contained in the second tank 170 is supplied to the cathode cell 125 through the conduit 175 and the cathode electrolyte 150 supplied to the cathode cell 125 is discharged through the conduit 180 And then flows into the second tank 170. The positive electrode electrolyte solution 140 and the negative electrode electrolyte solution 150 are circulated and charged and discharged while the positive electrode electrolyte 140 and the negative electrode electrolyte 150 flow in the flow cell.

Wherein the anode electrolyte 140 comprises a cathode active material and the anode electrolyte 150 comprises a cathode active material and the anode electrolyte 140 and the cathode electrolyte 150 comprise an aqueous solvent for dissociating the active material, The active material has a larger redox potential than the negative electrode active material.

The positive electrode active material is a Fe (terpy) ₂ X _n (where, n is a natural number of 1 or 2, X is ^{_{SO 4 2-, Cl -, Br}} -, I -, F -, I 3 -, I 2 F - , Br ₂ F ^- , Cl ₂ F ^- , I ₂ Br ^- , Br ₂ I ^- , NO ₃ ^- , PF ₆ ^- , ClO ₄ ^- , BF ₄ ^- , SbF ₆ ^- , CF ₃ SO ₃ ^{- _{2 N -, (CF 3 SO}} 2) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C -, CF 3 CO 2 -, C 3 F 7 CO 2 - C ₂ O ₄ ^2- and CH ₃ CO ₂ ^- ).

An example of a method for producing the above-mentioned Fe (terpy) ₂ X _n will be described. And FeX _n (where, n is a natural number of 1 or 2, X is ^{_{SO 4 2-, Cl -, Br}} -, I -, F -, I 3 -, I 2 F -, Br 2 F -, Cl 2 F ^{_{-, I 2 Br -, Br}} 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 -, CF 3 SO 3 -, (CN) 2 N -, (CF 3 SO 2 ^{_{) 2 N -, (C 2}} F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C -, CF 3 CO 2 -, C 3 F 7 CO 2 - C 2 O 4 2 - and CH ₃ CO ₂ ^- is dissolved in a solvent such as distilled water, and 2,2 ': 6', 2 "-terpyridine is dissolved in a solvent such as ethanol. Then, the FeX _n is dissolved and stirred in the solution, The resultant is distilled under reduced pressure to remove the solvent, and precipitated with acetone or the like, followed by filtration under reduced pressure to obtain Fe (terpy) ₂ X _n .

The schematic structure of Fe (terpy) ₂ SO ₄ (bis (2,2 ': 6', 2 "-terpyridine) iron (ⅱ) sulfate) as an example of a cathode active material is shown in the following structural formula 1.

[Structural formula 1]

The method for producing the above-mentioned Fe (terpy) ₂ SO ₄ will be described in detail. FeSO ₄ The amount corresponding to 5 mmol of hydrate (for example, FeSO ₄ .6H ₂ O) was weighed and dissolved in distilled water. The amount equivalent to 2 equivalents of 2,2 ': 6', 2 "-terpyridine was weighed and dissolved in a solvent such as ethanol After dissolving, FeSO ₄ hydrate was dissolved in the solution, and the mixture was stirred for 2 hours. The resulting mixture was distilled under reduced pressure to remove the solvent, and then precipitated with acetone and filtered under reduced pressure to obtain Fe (terpy) ₂ SO ₄ .

The negative electrode active material includes NaFe (EDTA) (Ferric sodium ethylenediaminetetraacetate). As the negative electrode active material, a hydrate form such as NaFe (EDTA) .3H ₂ O may be used. The schematic structure of the NaFe (EDTA) is shown in the following structural formula 2.

[Structural formula 2]

The at least one electrolyte solution selected from the cathode electrolyte 140 and the cathode electrolyte 150 may further include a supporting electrolyte. The supporting electrolyte is an electrolyte which is not electrolyzed but is put into an electrolyte to increase the electric conductivity of the electrolyte. Wherein the supporting electrolyte comprises an electrolyte comprising a cation and an anion, wherein the cation comprises at least one material selected from a quaternary ammonium ion, a polymeric ammonium ion, a lithium ion, a sodium ion, a hydrogen ion and a potassium ion, ^{-, Br -, I -,} F -, I 3 -, I 2 F -, Br 2 F -, Cl 2 F -, I 2 Br -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 _{^{-, BF 4 -, SbF 6}} -, CF 3 SO 3 -, (CN) 2 N -, (CF 3 SO 2) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2 ) ₃ C ^- , CF ₃ CO ₂ ^- , C ₃ F ₇ CO ₂ ^- and CH ₃ CO ₂ ^- , and the supporting electrolyte preferably has a concentration of 0.01 to 5 M .

The quaternary ammonium ion may be substituted by a group selected from the group consisting of R ₁ , R ₂ , R ₃ and R ₄ alkyl groups (R ₁ , R ₂ , R ₃ and R ₄ are methyl, ethyl, propyl, isopropyl, butyl, isobutyl group, a pentyl group, a hexyl group, and may include a hexyl group, or a benzyl group), a quaternary ammonium ion _{(R 1 R 2 R 3 R} 4 N +) containing a sayikeu. R ₁ , R ₂ , R ₃ and R ₄ may be the same or different alkyl groups. The polymeric ammonium ion may be one in which the ammonium ion is chain-linked.

The positive electrode active material used for the positive electrode electrolyte has a concentration of 0.0001 to 2.0M, and the negative electrode active material used for the negative electrode electrolyte has a concentration of 0.0001 to 2.0M.

The positive electrode electrolyte 140 and the negative electrode electrolyte 150 include an aqueous solvent for dissociating the electrolyte, and the aqueous solvent may be a solvent containing water (H ₂ O).

The positive electrode electrolyte 140 is supplied to wet the positive electrode collector 110 and the negative electrode electrolyte 150 is supplied to wet the negative electrode collector 120.

As the cathode current collector 110 and the anode current collector 120, a plate type, a grid type mesh type, a sponge type felt type, or the like may be used. Examples of the positive electrode collector 110 and the negative electrode collector 120 include a conductive metal such as Au, Pt, Ni and the like, a conductive metal composite containing a metal such as Au, Pt, and Ni, a polyacetylene, Electrically conductive felt such as nickel felt, carbon felt, and graphite felt having the same specific surface area, relatively low cost, and excellent electrical conductivity can be used. In particular, carbon felt, which is a carbon material, has excellent rigidity and electrical conductivity, which can contribute to durability and power output.

The separation membrane 130 disposed between the cathode current collector 110 and the anode current collector 120 may be formed of an anion exchange membrane or both ion exchange membranes. For example, Nafion has strong mechanical strength and high alkali resistance, and can be used as a separator having negative ion selectivity.

The flow cell according to the present invention is advantageous in that it can be constructed in a short time because the structure of the battery is simple and the installation is simple. In addition, when a single stack malfunctions, the stack battery can be replaced only by the stack, so that it can be easily repaired, which is convenient for maintenance and is suitable for long-term use. Accordingly, chemical plants, Internet data centers (IDC), semiconductor companies, etc., where power stability is indispensable in the industry, are highly likely to be used as buffer for electric power outages. In addition, it is highly likely to be used as a substitute for a pumped-storage power plant, which was difficult to construct due to environmental degradation. In addition, it is possible to construct various sizes of facilities that output the power produced by the new and renewable energy generation complex where the quality of electric power is not constant and output the uniform quality power. In particular, It is expected that large-scale facilities of flow cells in which organic solvents can be utilized are also possible.

Hereinafter, experimental examples according to the present invention will be specifically shown, and the present invention is not limited to the following experimental examples.

<Experimental Example>

1. Preparation of Supported Electrolyte Solution

The supporting electrolyte used was a 1M sodium acetate solution at pH 4. The method of preparing the supporting electrolyte solution is as follows. 13.82 g of sodium acetate trihydrate (Daejung Chem. Co., 98.5%) was weighed, placed in a 100 mL volumetric flask, and water (H ₂ O) was added to the 100 mL mark to prepare the sodium acetate solution.

2. Preparation of active material solution

As a cathode active material _{Fe (terpy) 2 SO 4)} (Bis (2,2 ': 6', 2 "-terpyridine) iron (ⅱ) was used as the _{sulfate), Fe (terpy) 2} SO 4 has the following steps .

The amount corresponding to 5 mmol of FeSO ₄ .6H ₂ O (Daejung Chem. Co., 98.5%) was weighed and dissolved in distilled water. 2 equivalents of 2,2 ': 6', 2 "-terpyridine (Alfa Aesar., 97%) were weighed and dissolved in ethanol. The solution was mixed with the solution in which FeSO ₄ .6H ₂ O was dissolved. The reaction mixture was distilled under reduced pressure to remove the solvent, followed by precipitation with 200 mL of acetone (Daejung Chem Co., 99.5%), followed by filtration under reduced pressure to obtain Fe (terpy) ₂ SO ₄ . The above reaction is shown in Scheme 1 below.

[Reaction Scheme 1]

The amount of Fe (terpy) ₂ SO ₄ obtained through synthesis was weighed to an amount corresponding to 0.08 M, put into a 10 mL volumetric flask, and then the supporting electrolyte solution was added to a 10 mL mark to prepare a positive electrode electrolyte solution.

NaFe (EDTA) (Ferric sodium ethylenediaminetetraacetate) was used as an anode active material. Ferric sodium ethylenediaminetetraacetate hydrate (NaFe (EDTA) · 3H ₂ O) (Samchun pure Chem. Co.) was weighed in an amount corresponding to 0.08 M and placed in a 10 mL volumetric flask. .

Table 1 below shows the molecular weights and weights of the active materials used in the experimental examples.

Active material Molecular weight (g / mol) Weight (g)
(Based on 0.08M 10ml) Fe (terpy) ₂ SO ₄ 618.4476 0.4948 NaFe (EDTA) · 3H ₂ O 421.10 0.3438

3. Whole-house pretreatment

Carbon felt (NIPPON CARBON) used as a current collector was activated at 400 DEG C for 48 hours.

4. Cell assembly

A cell was prepared as follows.

As shown in FIGS. 2 to 11, the cells are stacked and assembled in the order of an outer case, a cathode current collector, a gasket, a membrane, a gasket, an anode current collector, and an outer case. In order to reduce the risk of leakage and the internal resistance of the cell, a strong pressure was applied to the outside of the cell using a bolt and a nut. Then, a carbon felt was wetted by inserting a positive electrode electrolyte and a negative electrode electrolyte on a carbon felt separated by a membrane.

2 to 4 were fabricated by using carbon felt as a positive collector and negative electrode collector and Nafion as an anion exchange membrane as a separator. Figs. 2 to 4 are photographs of an experimental battery cell. 5 is a cross-sectional view illustrating a method of assembling a battery cell. FIG. 6 is a front view showing an outer case of the battery cell, FIG. 7 is a side view showing an outer case of the battery cell, and FIG. 8 is a plan view showing an outer case of the battery cell. FIG. 9 is a front view showing the cover of the battery cell, FIG. 10 is a side view showing the cover of the battery cell, and FIG. 11 is a plan view showing the cover of the battery cell.

The battery cell was fabricated as follows. 5, a carbon felt 220a used as a positive electrode current collector is inserted into a concave portion 212a provided in the outer case 210a, and a silicone felt 220a is inserted into the concave portion 212a to prevent the electrolyte from leaking to the outside. A concave portion 212a is attached to the gasket 230a in a sealed manner and a separating film 240 is provided adjacent to the gasket 230a and a concave portion 112b The carbon felt 220b used as a negative electrode current collector is inserted into the gasket 230b and the concave portion 212b of the gasket 230b made of silicone is sealed to prevent the electrolyte from leaking to the outside. So that the outer case 210a and the outer case 210b are pressed together using a bolt to fabricate a battery cell.

As shown in FIGS. 6 to 8, the outer case 210 is provided with a concave portion 212 as a space capable of accommodating a carbon felt used as a cathode current collector and a cathode current collector. In addition, the outer case 210 is provided with a through hole 214 into which a bolt is inserted. The outer case 210 is provided with an opening 216 for injecting an electrolyte solution or for inserting the cap 250.

As shown in FIGS. 9 to 11, the lid 250 is provided with a through hole 252 for inserting a lead connecting a positive current collector or a negative current collector with a power supply.

5. Analysis Method

Cyclic voltammetry (CV) measurement was performed to observe the redox behavior of the active materials. Cyclic voltametry (CV) was measured using an SP-150 instrument from BioLogic science instruments. The working electrode was a platinum electrode (BASi, diameter 3 mm), the auxiliary electrode was platinum wire, the reference electrode was a saturated calomel electrode, and the scanning speed was 10 mV s ^-1 .

FIG. 12 is a graph showing electrochemical oxidation and reduction potentials measured as a measurement result using an active material, and FIG. 13 is a graph showing charge / discharge curves measured as a measurement result using an active material. Charging and discharging tests were carried out using a cell test system (Wonatech, Co. Ltd). The current density of charge and discharge was set to 6.432 mA, and charge and discharge proceeded to constant current (CC).

12 and 13, it was predicted that the active material would provide a voltage of about 1.0 V as a result of predicting the potential that can be provided at the time of discharging (indicated by an arrow) (see FIG. 12) Thereby providing a discharge value of approximately 1 V (see FIG. 13).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, This is possible.

110: positive electrode collector
115: anode cell
120: cathode collector
125: cathode cell
130:
140: anode electrolyte
150: cathode electrolyte
155: First tank
170: Second tank
160, 165, 175, 180: conduit

Claims (5)

A flow cell in which a positive electrode current collector, a negative electrode current collector, and a separator disposed between the positive electrode current collector and the negative electrode current collector are supplied with a positive electrode electrolyte and a negative electrode electrolyte to charge and discharge,
The cathode electrolytic solution and Fe (terpy) ₂ X _n (where, n is a natural number of 1 or 2 as a cathode active material, X is ^{_{SO 4 2-, Cl -, Br}} -, I -, F -, I 3 -, I ^{_{2 F -, Br 2 F -}} , Cl 2 F -, I 2 Br -, Br 2 I -, NO 3 -, PF 6 -, ClO 4 -, BF 4 -, SbF 6 -, CF 3 SO 3 -, ^{_{(CN) 2 N -, (}} CF 3 SO 2) 2 N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) 3 C -, CF 3 CO 2 -, C 3 F 7 CO ₂ ^- C ₂ O ₄ ^2- and CH ₃ CO ₂ ^- ),
Wherein the negative electrode active material comprises NaFe (EDTA) (ferric sodium ethylenediaminetetraacetate) as a negative electrode active material.
The method according to claim 1, wherein the at least one electrolyte solution selected from the cathode electrolyte and the cathode electrolyte further comprises a supporting electrolyte,
Wherein the supporting electrolyte is an electrolyte including a cation and an anion,
Wherein the cation comprises at least one material selected from a quaternary ammonium ion, a polymeric ammonium ion, a lithium ion, a sodium ion, a hydrogen ion and a potassium ion,
The anion is ^{Cl -, Br -, I -} , F -, I 3 -, I 2 F -, Br 2 F -, Cl 2 F -, I 2 Br -, Br 2 I -, NO 3 -, PF 6 ^{_{-, ClO 4 -, BF 4}} -, SbF 6 -, CF 3 SO 3 -, (CN) 2 N - 2 N, (C 2 F 5 SO 2) - -, (CF 3 SO 2) 2 N, ( CF ₃ SO ₂ ) ₃ C ^- , CF ₃ CO ₂ ^- , C ₃ F ₇ CO ₂ ^- and CH ₃ CO ₂ ^-
Wherein the supporting electrolyte has a concentration of 0.01 to 5M.
The lithium secondary battery according to claim 1, wherein the cathode active material has a concentration of 0.0001 to 2.0M,
Wherein the anode active material has a concentration of 0.0001 to 2.0M.
The flow cell according to claim 1, wherein the cathode electrolyte and the cathode electrolyte include an aqueous solvent for dissociating the electrolyte.
The flow cell according to claim 1, wherein the cathode current collector and the anode current collector include a felt having electrical conductivity.

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