KR20180121740A - Bipolar plate containing a flow module and redox flow battery comprising thereof - Google Patents

Abstract

The present invention relates to a bipolar plate flow path module for forming a bipolar plate flow path with a plurality of unit modules to minimize concentration fluctuation of an electrolyte between an inlet and an outlet of the flow path, a bipolar plate comprising the flow path module, and a redox flow battery using the same. The bipolar plate including the flow path module according to the present invention includes: a bipolar body having a first manifold through which an electrolyte flows in and a second manifold through which an electrolyte flows out; a flow path module including an injection flow path formed on a surface of the bipolar body in contact with the electrode and adapted to receive and inject the electrolyte through the first manifold, a plurality of unit flow paths each having the same length and each of which receives an electrolyte from an injection flow path and contacts the electrolyte with the electrode, and an outflow path portion receiving the electrolyte from each of the plurality of unit flow paths and draining out the electrolyte through the second manifold.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a bipolar plate including a bipolar plate containing a flow module and a redox flow battery,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a redox flow cell, and more particularly, to a bipolar plate including a flow path module for constituting a flow path of a bipolar plate with a plurality of unit modules and minimizing concentration fluctuation of an electrolyte between a flow path inlet and an outlet, And a redox flow cell using the same.

To solve air pollution caused by the use of fossil fuels, development is being made to produce renewable energy such as solar and wind power plants. As the proportion of renewable energy gradually increases, it is important to efficiently manage the surplus energy produced at peak times.

In order to manage surplus energy, a high-capacity energy storage system is required. Redox flow battery (RFB) is used for large-scale energy storage in terms of cost efficiency, long lifetime and large energy capacity. It is one of the most economical systems.

This redox flow cell has the advantage of stacking a plurality of unit cells and stacking them, but has a problem of low energy density and low energy efficiency. Here, the energy efficiency of the redox flow cell is closely related to the stack structure, the flow structure, the flow distribution, and the concentration gradient of the active material in the electrode, in addition to the core components.

As the redox flow cell uses an electrolyte having a high ionic conductivity, a leakage current (shunt-crrent) occurs due to formation of a passage through which the electrolyte moves, and this is recognized as one of the major causes of energy efficiency reduction. Since the voltage loss of the redox flow cell is also caused by the flow rate distribution of the electrolytic solution and the distribution of the flow rate through the manifold, a manifold design and a flow path design that can optimize the flow distribution in order to minimize the voltage loss are needed.

The bipolar plate used in the redox flow cell is mainly composed of a graphite plate having a flow-free pattern. Recently, however, studies have been made to introduce a flow path into a bipolar plate to improve the output characteristics.

Korean Patent Registration No. 20-0463822 discloses a "bipolar plate for a redox flow cell" in which a flow path is formed.

The disclosed bipolar plate has an electrolyte solution supply line, a plurality of longitudinal flow paths formed at regular intervals along the longitudinal direction of the body, and an electrolyte discharge line.

Here, a concentration deviation occurs between the electrolyte solution supply line and the electrolyte solution discharge line due to the plurality of longitudinal flow paths formed between the electrolyte solution supply line and the electrolyte solution discharge line.

On the other hand, in order to apply tens of MWh class ESS, it is essential to make the redox flow battery large in size and high output through high current density operation. Large-area bipolar plates are needed to maximize redox flow cells.

When the disclosed bipolar plate is large-sized, the distance between the electrolyte supply line and the electrolyte discharge line increases, so that there is a problem that a greater concentration deviation occurs as the bipolar plate becomes larger.

Accordingly, it is an object of the present invention to provide a bipolar plate including a channel module capable of minimizing a concentration deviation between an inlet through which an electrolyte flows in a bipolar plate and an outlet through which the electrolyte flows, and a redox flow cell using the same.

The flow path module for a bipolar plate according to the present invention is formed on a surface of a bipolar body in contact with an electrode and has an injection flow path for injecting an electrolyte solution and an electrolytic solution from the injection flow path, And an outflow channel portion that receives the electrolyte solution from each of the plurality of unit flow channels and flows out the electrolyte solution.

In the flow path module for a bipolar plate according to the present invention, the injection path portion may include an injection portion for injecting an electrolyte solution, a plurality of unit flow paths for distributing an electrolyte solution to the plurality of unit flow paths, And a plurality of injection channels.

In the flow path module for a bipolar plate according to the present invention, the plurality of unit flow paths are each characterized in that the residence time of the electrolyte solution is the same.

In the flow path module for a bipolar plate according to the present invention, each of the plurality of unit flow paths may include a plurality of contact portions extending from the injection channel and formed parallel to each other at a predetermined interval, And a bent portion that connects the upper and lower plates to each other in a staggered manner.

In the flow path module for a bipolar plate according to the present invention, the outflow channel portion may be divided into a plurality of unit flow paths and a plurality of outflow channels, And an outlet portion for receiving and discharging the electrolytic solution from the channel is formed.

In the flow path module for a bipolar plate according to the present invention, the plurality of unit flow paths are arranged in directions perpendicular to each other.

The bipolar plate including the flow path module according to the present invention includes a bipolar body having a first manifold through which an electrolyte flows and a second manifold through which an electrolyte flows out, the bipolar body being formed on a surface contacting the electrodes of the bipolar body, A plurality of unit flow paths each of which has an equal length and which receives an electrolyte solution from the injection flow path portion and which is in contact with an electrolyte solution; And an outflow channel part for receiving and discharging the electrolytic solution through the second manifold.

In the bipolar plate including the channel module according to the present invention, the bipolar body is formed of a material including at least one of graphite, carbon material, polymer composite, and metal.

In the bipolar plate including the channel module according to the present invention, the electrode may be formed of a material such as carbon felt, carbon paper, carbon cloth, carbon coating layer, metal foam Metal foam and a membrane.

The bipolar plate including the flow path module according to the present invention includes a bipolar body having a first manifold for introducing an electrolyte solution and a second manifold for discharging an electrolyte solution, A branch channel formed on a surface of the bipolar body that is in contact with the electrode and receives an electrolyte solution from the plurality of first branch channels and injects the electrolytic solution; A plurality of flow path modules each including a plurality of unit flow paths having the same length and an outflow flow path portion for transferring the electrolyte solution from each of the plurality of unit flow paths to discharge the electrolyte solution, And a plurality of second branch channels which flow out into the manifold It shall be.

In the bipolar plate including the flow path module according to the present invention, the plurality of flow path modules are arranged in a horizontal direction with respect to each other.

The redox flow cell according to the present invention includes a bipolar body having a first manifold through which an electrolytic solution flows and a second manifold through which an electrolyte flows out, a second bipolar body formed on a surface of the bipolar body in contact with the electrodes, A plurality of unit flow paths each having the same length and having an electrolyte solution in contact with the electrolyte solution; a plurality of unit flow paths each having the same length, And a flow path module including an outflow channel portion through which the gas is discharged through the second manifold.

The bipolar plate including the flow path module according to the present invention is characterized in that a plurality of unit flow paths having the same length are formed between the injection flow path portion and the outflow flow path portion and the plurality of unit flow paths receive the electrolyte solution from the injection flow path portion, It is possible to minimize the concentration deviation between the injection path portion and the outflow path portion.

1 is a schematic diagram showing a redox flow cell according to the present invention.
2 is a view illustrating a bipolar plate according to an embodiment of the present invention.
3 is a view illustrating a bipolar plate according to another embodiment of the present invention.

In the following description, only parts necessary for understanding the embodiments of the present invention will be described, and the description of other parts will be omitted so as not to obscure the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram showing a redox flow cell according to the present invention.

Referring to FIG. 1, a redox flow cell 600 according to the present invention includes a unit cell 100, a negative electrode electrolyte tank 200, and a positive electrode electrolyte tank 300.

The cathode unit 20 and the anode unit 30 are disposed so that the unit cells 100 face each other with the separator 10 interposed therebetween.

Here, the separator 10 serves to separate the cathode electrolyte and the anode electrolyte from each other during charging and discharging, and to selectively move ions only during charging and discharging. The separation membrane (10) is not particularly limited as the separation membrane (10) is commonly used in the art. For example, the separator 10 may be a polypropylene (PP) porous film. The separation membrane 10 may be a cation exchange membrane obtained by sulfonating a styrene-divinylbenzene copolymer, a cation exchange membrane having a sulfonic acid group introduced thereinto based on a copolymer of tetrafluoroethylene and perfluorosulfonylethoxyvinylether, A cation exchange membrane comprising a copolymer of tetrafluoroethylene and perfluorovinyl ether having a carboxy group in the side chain, a cation exchange membrane having a sulfonic acid group introduced thereinto based on an aromatic polysulfone copolymer, a copolymer of styrene-divinylbenzene as a base , An anion exchange membrane obtained by introducing a chloromethyl group and aminated, a quaternary pyridinium anion exchange membrane of a copolymer of vinylpyridine-divinylbenzene, an anion exchange membrane in which a chloromethyl group is introduced based on an aromatic polysulfone copolymer, Exchange membrane or the like can be used.

The cathode portion 20 is disposed to face the anode portion 30 with respect to the separator 10 and includes a cathode 21, a first flow frame 22, a first bipolar plate 23, And may be fixed by the first cell frame 25.

The cathode 21 may be inserted and disposed inside the first flow frame 22. The negative electrode 21 may be made of nonwoven fabric, carbon fiber, carbon paper or the like, but is not limited thereto. Preferably, the cathode 21 may be a carbon felt electrode formed of polyacrylonitrile (PAN) or rayon (Rayon) series. For example, the cathode 21 may be formed of one of carbon felt, carbon paper, carbon cloth, carbon coating layer, metal foam, and membrane. .

The first flow frame 22 may have a cathode 21 inserted therein and a channel serving as a passage for flowing the cathode electrolyte through the cathode 21. As the material of the first flow frame 22, a plastic resin such as polyethylene (PE), polypropylene (PP), polystyrene (PS), or vinyl chloride (PVC)

The first bipolar plate (23) is stacked on the outside of the first flow frame (22). The first bipolar plate 23 may be a conductive plate. For example, the first bipolar plate 23 may be a graphite plate.

The first current collector 24 is a passage through which electrons move, and serves to receive electrons from the outside when charging or to emit electrons to the outside when discharging. For example, copper or brass may be used as the current collector.

The first cell frame 25 may serve to fix the cathode 21, the first flow frame 22, the first bipolar plate 23, and the first collector 24. The first cell frame 25 may have an electrolyte injection port and an electrolyte discharge port.

The anode part 30 is arranged to face the cathode part 20 with respect to the separator 10 and the anode part 31 is connected to the second flow frame 32 through the second bipolar plate 33 and the current collector 34, And can be fixed by the second cell frame 35. [

On the other hand, the configuration of the anode portion 30 is substantially the same as that of the cathode portion 20, and a detailed description thereof will be omitted.

The negative electrode electrolyte tank 200 stores the negative electrode electrolyte supplied to the negative electrode portion 20 of the unit cell 100 and is connected to the electrolyte inlet and the electrolyte outlet of the first cell frame 25 through the first inlet pipe 210, The first outlet pipe 230 is connected to circulate the cathode electrolyte to the first cell frame 25. At this time, a first pump 220 may be provided between the first inlet pipe 210 and the first cell frame 25 to circulate the negative electrode electrolyte.

The positive electrode electrolyte tank 300 stores the positive electrode electrolyte supplied to the positive electrode portion 30 of the unit cell 100 and the electrolyte inlet and the electrolyte outlet of the second cell frame 35 are connected to the second inlet pipe 310, And the second outflow pipe 330 is connected to circulate the positive electrode electrolyte into the second cell frame 35. At this time, a second pump 320 may be provided between the second inlet pipe 310 and the second cell frame 35 to circulate the anode electrolyte.

Here, a generally used redox couple may be used as a negative electrode electrolyte and a positive electrode electrolyte solution. For example, the electrolytic solution may be an aqueous electrolytic solution such as V / V, Zn / Br, Zn / Ce or Fe / Cr or an organic electrolytic solution.

Hereinafter, the first and second bipolar plates 23 and 33 according to the present invention will be described in detail with reference to examples.

2 is a view illustrating a bipolar plate according to an embodiment of the present invention.

Referring to FIG. 2, a bipolar plate 400 according to an embodiment of the present invention includes a bipolar body 410 and a flow path module 420.

The bipolar body 410 may include a first manifold 411 through which the electrolyte flows, and a second manifold 412 through which the electrolyte flows.

Here, the first and second manifolds 411 and 412 may be formed on the upper and lower sides of the center of the bipolar body 410. The first and second manifolds 411 and 412 communicate with the flow frame, the current collector, or the cell frame, and are connected to the electrolyte tank to receive or discharge the electrolyte from the electrolyte tank. For example, the electrolyte flowing into the first manifold 411 through the electrolyte tank may pass through the flow path module 420, make contact with the electrodes, and then circulate through the second manifold 412 to the electrolyte tank again.

The flow path module 420 is formed on the center portion of the bipolar body 410, that is, on the surface contacting the electrodes, and allows the electrolytic solution to pass therethrough, thereby inducing an electrochemical reaction between the electrodes and the electrolytic solution.

The flow path module 420 includes an injection path portion 421, a unit flow path 422, and an outflow path portion 423.

The injection flow path portion 421 is formed on a surface contacting the electrode of the bipolar body 410, and an electrolyte can be injected. The injection path portion 421 includes an injection portion 421a connected to the first manifold 411 to supply and receive the electrolyte solution, a plurality of unit flow paths 422 corresponding to the plurality of unit flow paths 422 from the injection portion 421a, And a plurality of injection channels 421b for supplying an electrolyte solution to each of the plurality of unit flow paths 422 may be formed.

The plurality of unit flow paths 422 may be connected to the injection channel 421b to receive the electrolyte solution. The unit flow path 422 may be formed at a portion of the bipolar body 410 that is in contact with the electrode, so that the electrolyte may contact the electrode. The unit flow paths 422 may be arranged in directions perpendicular to each other. The unit flow path 422 may be disposed in a direction perpendicular to the first manifold 411 and the second manifold 412 while being spaced apart from the first manifold 411 by a predetermined distance, (421b) or the outflow channel (423a) so as to provide a space for forming the inlet channel (421b) or the outlet channel (423a) . Accordingly, the injection channel 421b or the outflow channel 423a may be formed on both sides of the unit flow path 422 to supply the electrolyte solution to the unit flow paths 422, respectively, or to discharge the electrolyte solution.

The residence times in which the electrolytic solution stays in each of the plurality of unit flow paths 422 can be set equal to each other. The unit flow path 422 extends from the injection channel 421b and includes a plurality of contact portions 422a formed parallel to each other at a predetermined interval and a plurality of contact portions 422a bent at the ends of the contact portions 422a, And a bending portion 422b that is staggered. That is, the unit flow path 422 may be formed in a serpentine shape.

The outflow channel portion 423 includes a plurality of outflow channels 423a that are distributed in a corresponding number to the plurality of unit flow channels 422 and are discharged from the plurality of unit flow channels 422 by receiving the electrolyte solution, And an outlet 423b that receives the electrolyte solution from the second manifold 412 and flows out to the second manifold 412.

On the other hand, concentration inevitably occurs between the electrolyte inflow point and the outflow point of the unit flow path 422.

Accordingly, the bipolar plate 400 according to the embodiment of the present invention has a plurality of the unit flow paths 422, so that the concentration deviation can be dispersed so that the bipolar plate 400 is brought into contact with the electrode with a concentration deviation that can be generated in one unit flow path 422 It is possible to cover all the areas.

The bipolar plate 400 including the flow path module according to the embodiment of the present invention includes a plurality of unit flow paths 422 having the same length between the injection path portion 421 and the outflow path portion 423, The concentration fluctuation between the injection flow channel unit 421 and the outflow channel unit 423 can be minimized by allowing the unit flow channel 422 of the unit flow channel unit 422 to receive the electrolyte solution from the injection flow channel unit 421.

Hereinafter, a bipolar plate according to another embodiment of the present invention will be described.

3 is a view illustrating a bipolar plate according to another embodiment of the present invention.

3, a bipolar plate 500 according to another embodiment of the present invention includes a bipolar plate 400, first and second branch channels 510 and 520, (420) are provided in plural. Therefore, the same reference numerals are used for the same components, and redundant explanations are omitted.

A bipolar plate 500 according to another embodiment of the present invention includes a bipolar body 410 having first and second manifolds 411 and 412 formed thereon and a plurality of A plurality of second branch channels 520 which receive the electrolyte solution from the first branch channel 510, the plurality of flow path modules 422 and the plurality of flow path modules 422 and flow out to the second manifold 412, .

The first branch channel 510 is distributed from the first manifold 411 and connected to the injection flow path portion 421 of each of the plurality of flow path modules 420 to transfer the electrolyte solution to each of the plurality of flow path modules 420 . The first branch channel 510 has a shape in which the cross-sectional area and length of the first branch channel 510 increases as the distance between the first branch channel 510 and the injection channel portion 421 of each of the plurality of flow channel modules 420 is increased with respect to the first manifold 411. Accordingly, the first branch channel 510 can uniformly supply the electrolyte solution to the flow path modules 420 from the first manifold 411, thereby minimizing the pressure loss.

The plurality of flow path modules 420 may be arranged in a horizontal direction. That is, when the area of the bipolar body 410 is increased by arranging the flow path modules 420 in which the unit flow paths 422 are arranged in the vertical direction in the horizontal direction, the number of the unit flow paths 422 in the flow path module 420 Or by adjusting the number of the flow-field modules 420.

The plurality of second branch channels 520 are connected to the outflow channel portions 423 of the plurality of flow channel modules 420 to allow the electrolyte discharged from the outflow channel portions 423 to flow out to the second manifold 412 have.

The second branch channel 520 has a shape in which the cross-sectional area and length of the second branch channel 520 increases as the distance from the outflow channel portion 423 of each of the plurality of flow channel modules 420 is increased with respect to the second manifold 412. Accordingly, the second branch channel 520 can uniformly discharge the electrolyte to the second manifold 411, thereby minimizing the pressure loss.

It should be noted that the embodiments disclosed in the drawings are merely examples of specific examples for the purpose of understanding, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

10: separator 20: cathode part
21: cathode 22: first flow frame
23: first bipolar plate 24: first current collector
25: first cell frame 30: anode part
31: anode 32: second flow frame
33: second bipolar plate 34: second collector
35: second cell frame 100: unit cell
200: cathode electrolyte tank 210: first inlet pipe
220: first pump 230: first outlet pipe
300: positive electrode electrolyte tank 310: second inlet pipe
320: second pump 330: second outlet pipe
400, 500: bipolar plate 410: bipolar body
411: first manifold 412: second manifold
420: flow path module 421:
421a: injection part 421b: injection channel
422: unit flow path 422a:
422b: bent portion 423: outflow channel portion
423a: outflow section 423b: outflow channel
510: first branch channel 520: second branch channel
600: redox flow cell

Claims (11)

A bipolar body having a first manifold through which the electrolyte flows and a second manifold through which the electrolyte flows;
An injection flow path formed on a surface of the bipolar body in contact with the electrode and adapted to receive and inject an electrolyte through the first manifold, an electrolyte solution supplied from the injection flow path to the electrode, A flow channel module including an outflow channel portion that receives the electrolyte solution from each of the plurality of unit flow channels and flows out the electrolyte solution through the second manifold;
Wherein the bipolar plate comprises a channel module. The method according to claim 1,
The infusion-
An injector for injecting an electrolyte;
A plurality of injection channels that are distributed from the injection unit and supply an electrolyte solution to each of the plurality of unit flow channels;
Wherein the bipolar plate includes a bipolar plate. 3. The method of claim 2,
Wherein the plurality of unit flow paths each have the same residence time at which the electrolyte remains. The method of claim 3,
Wherein each of the plurality of unit flow paths includes:
A plurality of contact portions extending from the injection channel and formed parallel to each other at a predetermined interval;
A bending portion bent at an end of the contact portion and staggeredly connecting adjacent contact portions to each other;
Wherein the bipolar plate includes a bipolar plate. The method according to claim 1,
The outflow channel portion
A plurality of outflow channels for receiving and discharging the electrolyte solution from each of the plurality of unit flow paths;
An outlet for receiving and discharging the electrolyte from the plurality of outlet channels;
Wherein the bipolar plate includes a bipolar plate. The method according to claim 1,
Wherein the plurality of unit flow paths are arranged in a direction perpendicular to each other. The method according to claim 6,
Wherein the bipolar body is formed of a material including at least one of graphite, carbon material, polymer composite, and metal. The method according to claim 6,
The electrode may be one of carbon felt, carbon paper, carbon cloth, carbon coating layer, metal foam, and membrane. A bipolar plate containing a Euro module. A bipolar body having a first manifold through which the electrolyte flows and a second manifold through which the electrolyte flows;
A plurality of first branch channels distributed from the first manifold to supply an electrolyte;
An injection flow path formed on a surface of the bipolar body in contact with the electrodes for supplying and injecting electrolyte from the plurality of first branch channels, an electrolytic solution contacted to the electrodes by receiving the electrolytic solution from the injection flow channel, A plurality of unit flow paths having the same length, and a plurality of flow path modules including an outflow flow path portion for transferring the electrolyte solution from each of the plurality of unit flow paths to flow out the electrolyte solution;
A plurality of second branch channels receiving the electrolyte solution from the plurality of flow path modules and flowing out to the second manifold;
Wherein the bipolar plate comprises a channel module. 10. The method of claim 9,
Wherein the plurality of flow path modules are disposed in a horizontal direction with respect to each other. A bipolar body having a first manifold through which the electrolyte flows and a second manifold through which the electrolyte flows out, an injection flow path formed on a surface of the bipolar body in contact with the electrodes, A plurality of unit flow paths each having the same length, each of the unit flow paths having an electrolyte flow path through which the electrolyte flows from the plurality of unit flow paths, And a bipolar plate having a flow path module including an outflow channel portion.

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