KR101975972B1 - Bipolar plate containing a flow module and redox flow battery comprising thereof - Google Patents

Abstract

The present invention comprises a bipolar plate flow path module using a bipolar plate flow path module for minimizing the concentration variation of electrolyte between the flow path inlet and outlet, the bipolar plate including the flow path module and a redox flow battery using the same. It is about. The bipolar plate including the flow path module according to the present invention is formed on a surface in contact with the electrode of the bipolar body, the bipolar body formed with the first manifold for introducing the electrolyte and the second manifold for the electrolyte, the first manifold The electrolyte flows through the injection flow path unit for receiving and injecting the electrolyte solution, and receives the electrolyte solution from the injection flow path unit to contact the electrolyte solution, and receives the electrolyte solution from each of the plurality of unit flow paths and the plurality of unit flow paths having the same length. And a flow passage module including an outlet flow passage portion flowing out through the second manifold.

Description

Bipolar plate containing a flow path module and a redox flow battery using the same

The present invention relates to a redox flow battery, and more particularly, to a bipolar plate including a flow path module configured to configure a plurality of unit modules in a flow path of a bipolar plate, thereby minimizing variation in concentration of electrolyte between a flow path inlet and an outlet. It relates to a redox flow battery using the same.

In order to solve the air pollution caused by the use of fossil fuels, developments are being made to produce renewable energy such as solar and wind power plants. As the proportion of renewable energy increases gradually, it is important to efficiently manage the surplus energy produced during peak hours.

In order to manage surplus energy, an ultra high-capacity energy storage system is required. The redox flow battery (RFB) is used for large-scale energy storage in terms of cost efficiency, long life, and large energy capacity. One of the most economical systems.

Such a redox flow battery has an advantage of stacking and stacking a plurality of unit cells, but there are problems of low energy density and low energy efficiency. In addition to the core components, the energy efficiency of the redox flow battery is closely related to the stack structure, the flow path structure, the flow distribution, and the concentration gradient of the active material in the electrode.

As redox flow batteries use electrolytes having high ionic conductivity, leakage currents (shunt-crrent) are generated due to the formation of passages through which the electrolyte moves, which is recognized as one of the major causes of energy efficiency reduction. Since the voltage loss of such a redox flow battery is also caused by the flow rate distribution of the electrolyte and the flow rate distribution through the manifold, a manifold design and a flow path design capable of optimizing the flow rate distribution are required to minimize the voltage loss.

Bipolar plates used in redox flow batteries have been mainly used for non-flow pattern graphite plates. Recently, however, studies have been conducted to introduce flow paths into bipolar plates to improve output characteristics.

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

The disclosed bipolar plate has an electrolyte 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, the concentration variation occurs between the electrolyte supply line and the electrolyte discharge line by the plurality of longitudinal flow paths formed between the electrolyte supply line and the electrolyte discharge line.

Recently, in order to apply dozens of MWh-class ESSs, a large area of a redox flow battery and high power through high current density operation are necessary. Large area bipolar plates are required for large area redox flow cells.

When the disclosed bipolar plate has a large area, the distance between the electrolyte supply line and the electrolyte discharge line becomes farther, so that the larger the bipolar plate, the more severe concentration variation occurs.

Accordingly, an object of the present invention is to provide a bipolar plate and a redox flow battery using the same flow path module that can minimize the variation in concentration between the inlet and the outlet of the electrolyte inlet in the bipolar plate.

The bipolar plate channel module according to the present invention is formed on the surface in contact with the electrode of the bipolar body and the injection flow path portion for injecting the electrolyte, and receives the electrolyte from each of the injection flow path to contact the electrolyte to the electrode, the same length It includes a plurality of unit flow passages having, and an outflow passage portion for receiving the electrolyte from each of the plurality of unit flow passages to drain the electrolyte.

In the bipolar plate flow path module according to the present invention, the injection flow path portion is divided into an injection portion for injecting an electrolyte solution and a number corresponding to the plurality of unit flow passages from the injection portion to supply the electrolyte solution to each of the plurality of unit flow paths. It characterized in that it comprises a plurality of injection channels.

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

In the bipolar plate flow path module according to the present invention, each of the plurality of unit flow paths, the plurality of contact portions extending from the injection channel, spaced apart at regular intervals and formed in parallel, the contact portion bent at the end of the contact portion adjacent It characterized in that it comprises a bent portion to be connected to each other.

In the bipolar plate channel module according to the present invention, the outlet flow path portion is divided into a number corresponding to the plurality of unit flow paths, a plurality of outlet channels for receiving the electrolyte from each of the plurality of unit flow paths and the plurality of outlets It is characterized in that the outlet portion is formed to receive the electrolyte from the channel and outflow.

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

The bipolar plate including the flow path module according to the present invention is formed on a surface of the bipolar body in contact with the electrode of the bipolar body, the bipolar body is formed with a first manifold for introducing the electrolyte and the second manifold for flowing out the electrolyte, the first manifold An injection flow path unit for receiving and injecting an electrolyte through the fold, and receiving the electrolyte solution from the injection flow path unit to contact the electrolyte solution to the electrode, a plurality of unit flow paths having the same length and the electrolyte from each of the plurality of unit flow paths It characterized in that it comprises a flow path module including an outlet flow path for receiving the electrolyte flows out through the second manifold.

In the bipolar plate comprising a flow path module according to the invention, the bipolar body is characterized in that formed of a material comprising at least one of graphite, carbon material, polymer composite and metal material.

In the bipolar plate including the flow path module according to the present invention, the electrode is carbon felt, carbon paper, carbon cloth, carbon coating layer, metal foam ( It is characterized in that one of the metal foam) and the membrane (membrane).

The bipolar plate including the flow path module according to the present invention includes a bipolar body having a first manifold for introducing electrolyte and a second manifold for outflow of electrolyte, and a plurality of firsts distributed from the first manifold to supply electrolyte. It is formed on the branch channel, the surface in contact with the electrode of the bipolar body, the injection flow path portion for receiving and injecting the electrolyte solution from the plurality of first branch channels, respectively, the electrolyte is received from the injection flow path portion to contact the electrolyte solution to the electrode And a plurality of flow path modules including a plurality of unit flow passages having the same length and an outflow flow passage part for receiving the electrolyte solution from each of the plurality of unit flow passages and for discharging the electrolyte solution, and receiving the electrolyte solution from the plurality of flow path modules, respectively. A plurality of second branch channels exiting the manifold It shall be.

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

The redox flow battery according to the present invention is formed on a surface of the bipolar body in contact with the electrode of the bipolar body, the first manifold for introducing the electrolyte and the second manifold for the electrolyte is formed, through the first manifold An injection passage portion for receiving and injecting an electrolyte solution, and receiving an electrolyte solution from the injection passage portion to contact the electrolyte solution with each other, a plurality of unit flow passages having the same length, and an electrolyte solution received from each of the plurality of unit flow passages It includes a bipolar plate having a flow path module including an outlet flow path for flowing out through the second manifold.

The bipolar plate including the flow path module according to the present invention forms a plurality of unit flow paths having the same length between the injection flow path part and the outflow flow path part, and allows the plurality of unit flow paths to receive electrolyte from the injection flow path part, respectively. The variation in concentration between the injection passage portion and the outlet passage portion can be minimized.

1 is a schematic diagram showing a redox flow battery according to the present invention.
2 is a view showing a bipolar plate according to an embodiment of the present invention.
3 is a view showing 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, it should be noted that the description of other parts will be omitted so as not to distract from the gist of the present invention.

The terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings, and the inventors are appropriate to the concept of terms in order to explain their invention in the best way. It should be interpreted as meanings and concepts in accordance with the technical spirit of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. It should be understood that there may be variations and variations.

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

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

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

In the unit cell 100, the cathode part 20 and the anode part 30 are disposed to face each other with the separator 10 interposed therebetween.

Here, the separator 10 separates the cathode electrolyte and the cathode electrolyte from each other during charge and discharge, and selectively moves only ions during charge and discharge. The separator 10 is not particularly limited as the separator 10 is generally used in the art. For example, the separator 10 may use a polypropylene (PP) -based porous film. In addition, the separation membrane 10 is a cation exchange membrane obtained by sulfonating a styrene-divinylbenzene copolymer, a cation exchange membrane having a sulfonic acid group introduced with a tetrafluoroethylene and perfluorosulfonyl based on a copolymer of oxyvinyl ether, Based on a cation exchange membrane composed of a copolymer of tetrafluoroethylene and a perfluorovinyl ether having a carboxyl group on the side chain, an aromatic polysulfone copolymer based on a cation exchange membrane having a sulfonic acid group, and a copolymer of styrene-divinylbenzene Anion exchange membrane introduced with a chloromethyl group and aminated, an anion exchange membrane obtained by quaternization of a copolymer of vinylpyridine-divinylbenzene, and an aromatic polysulfone copolymer based on an aromatic polysulfone copolymer. Exchange membranes and the like can be used.

The negative electrode unit 20 is disposed to face the positive electrode unit 30 based on the separator 10, and has a negative electrode 21, a first flow frame 22, a first bipolar plate 23, and a current collector 24. It includes, 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 a 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). For example, the cathode 21 may be formed of one of carbon felt, carbon paper, carbon cloth, carbon coating layer, metal foam, and membrane. Can be.

The first flow frame 22 may have a negative electrode 21 inserted therein and a flow passage that is a passage for flowing the negative electrolyte into the negative electrode 21. The material of the first flow frame 22 may be a plastic resin such as polyethylene (PE), polypropylene (PP), polystyrene (PS), or vinyl chloride (PVC).

The first bipolar plate 23 is stacked outside the first flow frame 22. The first bipolar plate 23 may be a conductive plate. For example, a graphite plate may be used for the first bipolar plate 23.

The first current collector 24 serves as a path through which electrons move and receives electrons from the outside during charging or gives out electrons to the outside during discharge. For example, the current collector may be copper or brass.

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 current collector 24. The first cell frame 25 may be formed with an electrolyte inlet and an electrolyte outlet.

The anode part 30 is disposed to face the cathode part 20 with respect to the separator 10, and has a positive electrode 31, a second flow frame 32, a second bipolar plate 33, and a current collector 34. It may include, and may be fixed by the second cell frame 35.

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

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

The anode electrolyte tank 300 stores the anode electrolyte supplied to the anode portion 30 of the unit cell 100, the electrolyte inlet and the electrolyte outlet of the second cell frame 35, and the second inlet pipe 310, respectively. The second outlet pipe 330 is connected to circulate the anode electrolyte to the second cell frame 35. In this case, a second pump 320 may be provided to circulate the anode electrolyte between the second inlet pipe 310 and the second cell frame 35.

Here, a redox couple, which is generally applied, may be used as the cathode electrolyte and the cathode electrolyte. For example, the electrolyte solution may be an aqueous electrolyte solution such as V / V, Zn / Br, Zn / Ce, Fe / Cr, or an organic electrolyte solution.

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

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

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 have a first manifold 411 for introducing electrolyte and a second manifold 412 for flowing out electrolyte.

In this case, the first and second manifolds 411 and 412 may be formed at an upper side and a lower side with respect to the center of the bipolar body 410. The first and second manifolds 411 and 412 may communicate with the flow frame, the current collector, or the cell frame, and may be connected to the electrolyte tank to receive or flow 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 to contact the electrode and then circulate back to the electrolyte tank through the second manifold 412.

The flow path module 420 may be formed at the center of the bipolar body 410, that is, a surface contacting the electrode, to induce an electrochemical reaction between the electrode and the electrolyte by passing the electrolyte.

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

The injection flow path part 421 is formed on a surface of the bipolar body 410 in contact with the electrode and may inject the electrolyte solution. The injection flow path part 421 is connected to the first manifold 411 to distribute the injection part 421a for receiving and injecting the electrolyte solution and the number corresponding to the plurality of unit flow paths 422 from the injection part 421a. Thus, a plurality of injection channels 421b may be formed to supply electrolyte to each of the plurality of unit flow paths 422.

A plurality of unit flow paths 422 may be provided to be connected to the injection channel 421b to receive an electrolyte solution. The unit flow path 422 may be formed at a portion of the bipolar body 410 in contact with the electrode to contact the electrolyte solution with the electrode. The unit flow path 422 may be disposed in a direction perpendicular to each other. For example, the unit flow passages 422 may be disposed between the first manifold 411 and the second manifold 412 in a vertical direction with a predetermined distance therebetween, and each unit flow passage 422 may be an injection channel. 421b or an outlet channel 423a so that a space for forming the outlet channel 423a may be disposed so as to move upwards or downwards as much as a space for forming the injection channel 421b or the outlet channel 423a in a stepped manner Can be. Accordingly, the injection channel 421b or the outflow channel 423a may be formed at both sides of the unit flow path 422 to supply electrolyte to each unit flow path 422 or to receive electrolyte and flow out.

The plurality of unit flow paths 422 may be set to have the same dwell time in which the electrolyte stays. The unit flow path 422 extends from the injection channel 421b, and the plurality of contact portions 422a which are formed to be spaced apart at regular intervals in parallel with each other and the adjacent contact portions 422a that are bent at the ends of the contact portions 422a to each other. It may be composed of a bent portion 422b to be staggeredly connected. That is, the unit flow path 422 may be formed in a serpentine shape.

The outlet flow path part 423 is divided into a number corresponding to the plurality of unit flow paths 422, and receives a plurality of outlet channels 423a for receiving electrolyte from each of the plurality of unit flow paths 422, and a plurality of outlet channels ( Receiving the electrolyte from the 423a may include an outlet 423b for outflow to the second manifold 412.

On the other hand, the concentration variation is inevitably generated between the electrolyte solution inlet point and the outlet point of the unit flow path 422.

Accordingly, the bipolar plate 400 according to the exemplary embodiment of the present invention is arranged in a plurality of unit flow paths 422 to disperse the concentration variation so as to contact the electrode with the concentration deviation that may occur in one unit flow path 422. Can cover all areas.

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

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

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

Referring to FIG. 3, the bipolar plate 500 according to another embodiment of the present invention includes the configuration of the bipolar plate 400 and the first and second branch channels 510 and 520 according to an embodiment of the present invention. Except that 420 is provided in plurality, it has substantially the same structure. Therefore, the same reference numerals are used for the same configuration, and duplicate descriptions are omitted.

Bipolar plate 500 according to another embodiment of the present invention is a bipolar body 410, the first and second manifold (411, 412) is formed, and a plurality of distribution from the first manifold 411 to supply the electrolyte A plurality of second branch channels 520 that receive electrolyte from each of the first branch channels 510, the plurality of flow path modules 422, and the plurality of flow path modules 422, and flow out to the second manifold 412. Include.

Here, the first branch channel 510 is distributed from the first manifold 411 and connected to the injection flow path part 421 of each of the plurality of flow path modules 420 to transfer electrolyte to each of the plurality of flow path modules 420. Can be. In addition, the first branch channel 510 has a shape in which the cross-sectional area and the length of the first branch channel 510 increase as the distance from the injection channel portion 421 of each of the plurality of flow path modules 420 increases. Accordingly, the first branch channel 510 may minimize pressure loss by uniformly supplying the electrolyte solution to each flow path module 420 from the first manifold 411.

The flow path module 420 may be provided in plurality, and may be disposed in a horizontal direction. That is, when the flow path module 420 in which the unit flow path 422 is disposed in the vertical direction is disposed in the horizontal direction, when the area of the bipolar body 410 increases, the number of unit flow paths 422 in the flow path module 420 is increased. Alternatively, the cover may be adjusted by adjusting the number of flow path modules 420.

The plurality of second branch channels 520 may be connected to the outlet flow path parts 423 of the plurality of flow path modules 420, respectively, and may discharge the electrolyte solution discharged from the outlet flow path parts 423 to the second manifold 412. have.

In addition, the second branch channel 520 has a shape in which the cross-sectional area and the length of the second branch channel 520 increase as the distance from the outlet flow path 423 of each of the plurality of flow path modules 420 increases. Accordingly, the second branch channel 520 may minimize the pressure loss by uniformly flowing the electrolyte into the second manifold 411.

On the other hand, the embodiments disclosed in the drawings are merely presented specific examples to aid understanding, and are not intended to limit the scope of the invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

10 Separation membrane 20 Cathode portion
21 cathode 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 current collector
35: second cell frame 100: unit cell
200: cathode electrolyte tank 210: first inlet pipe
220: first pump 230: first outlet pipe
300: anode 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: injection flow path
421a: injection portion 421b: injection channel
422: unit flow path 422a: contact portion
422b: bend portion 423: outflow channel portion
423a: outlet 423b: outlet channel
510: first branch channel 520: second branch channel
600: Redox Flow Battery

Claims (11)

A bipolar body having a first manifold introducing the electrolyte and a second manifold flowing out the electrolyte;
A plurality of first branch channels distributed from the first manifold to supply electrolyte;
An injection flow path part formed on a surface of the bipolar body that is in contact with an electrode and receiving electrolyte from each of the plurality of first branch channels, and receiving electrolyte from the injection flow path to contact the electrolyte with the electrode; A plurality of flow path modules including a plurality of unit flow paths having the same length and an outflow flow path part which receives the electrolyte solution from each of the plurality of unit flow paths and discharges the electrolyte solution;
A plurality of second branch channels each receiving electrolyte from the plurality of flow path modules and flowing out to a second manifold; Including,
Each of the plurality of unit flow paths,
A plurality of contacts extending from the injection channel and spaced apart at regular intervals in parallel;
A bent portion that is bent at an end of the contact portion and alternately connects adjacent contact portions with each other; Including,
The injection flow path unit,
An injection unit for injecting an electrolyte solution;
A plurality of injection channels distributed from the injection unit and supplying an electrolyte solution to each of the plurality of unit flow paths; Including,
The outflow passage portion,
A plurality of outlet channels configured to receive electrolyte from each of the plurality of unit flow paths and to discharge the electrolyte;
An outlet part which receives electrolyte from the plurality of outlet channels and flows out; Including,
The plurality of unit flow passages each have the same residence time in which the electrolyte stays and are arranged in a direction perpendicular to each other.
And a plurality of flow path modules arranged in a horizontal direction with each other. delete delete delete delete delete The method of claim 1,
The bipolar body is a bipolar plate comprising a flow path module, characterized in that formed of a material comprising at least one of graphite, carbon material, polymer composite and metal material. The method of claim 1,
The electrode may be one of carbon felt, carbon paper, carbon cloth, carbon coating layer, metal foam, and membrane. Bipolar plate containing the euro module. delete delete A bipolar body having a first manifold for injecting electrolyte and a second manifold for outflow of electrolyte, formed on a surface contacting the electrode of the bipolar body, and an injection flow path part for receiving and injecting electrolyte through the first manifold And receiving electrolyte from each of the injection flow paths to contact the electrolyte with the electrodes, and receiving the electrolyte from each of the plurality of unit flow paths having the same length and each of the plurality of unit flow paths, and allowing the electrolyte to flow out through the second manifold. A bipolar plate having a flow path module including an outflow flow path; Including,
Each of the plurality of unit flow paths,
A plurality of contacts extending from the injection channel and spaced apart at regular intervals in parallel;
A bent portion that is bent at an end of the contact portion and alternately connects adjacent contact portions with each other; Including,
The injection flow path unit,
An injection unit for injecting an electrolyte solution;
A plurality of injection channels distributed from the injection unit and supplying an electrolyte solution to each of the plurality of unit flow paths; Including,
The outflow passage portion,
A plurality of outlet channels configured to receive electrolyte from each of the plurality of unit flow paths and to discharge the electrolyte;
An outlet part which receives electrolyte from the plurality of outlet channels and flows out; Including,
The plurality of unit flow passages each have the same residence time in which the electrolyte stays and are arranged in a direction perpendicular to each other.
The plurality of flow path modules are redox flow battery, characterized in that arranged in a horizontal direction with each other.

Images